2 * Copyright © 2014 Red Hat
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 #include <linux/bitfield.h>
24 #include <linux/delay.h>
25 #include <linux/errno.h>
26 #include <linux/i2c.h>
27 #include <linux/init.h>
28 #include <linux/kernel.h>
29 #include <linux/random.h>
30 #include <linux/sched.h>
31 #include <linux/seq_file.h>
32 #include <linux/iopoll.h>
34 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
35 #include <linux/stacktrace.h>
36 #include <linux/sort.h>
37 #include <linux/timekeeping.h>
38 #include <linux/math64.h>
41 #include <drm/display/drm_dp_mst_helper.h>
42 #include <drm/drm_atomic.h>
43 #include <drm/drm_atomic_helper.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_edid.h>
46 #include <drm/drm_fixed.h>
47 #include <drm/drm_print.h>
48 #include <drm/drm_probe_helper.h>
50 #include "drm_dp_helper_internal.h"
51 #include "drm_dp_mst_topology_internal.h"
56 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
57 * protocol. The helpers contain a topology manager and bandwidth manager.
58 * The helpers encapsulate the sending and received of sideband msgs.
60 struct drm_dp_pending_up_req {
61 struct drm_dp_sideband_msg_hdr hdr;
62 struct drm_dp_sideband_msg_req_body msg;
63 struct list_head next;
66 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
69 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
71 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
72 int id, u8 start_slot, u8 num_slots);
74 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
75 struct drm_dp_mst_port *port,
76 int offset, int size, u8 *bytes);
77 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
78 struct drm_dp_mst_port *port,
79 int offset, int size, u8 *bytes);
81 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
82 struct drm_dp_mst_branch *mstb);
85 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
86 struct drm_dp_mst_branch *mstb);
88 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
89 struct drm_dp_mst_branch *mstb,
90 struct drm_dp_mst_port *port);
91 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
94 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
95 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
96 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
98 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
99 struct drm_dp_mst_branch *branch);
101 #define DBG_PREFIX "[dp_mst]"
103 #define DP_STR(x) [DP_ ## x] = #x
105 static const char *drm_dp_mst_req_type_str(u8 req_type)
107 static const char * const req_type_str[] = {
108 DP_STR(GET_MSG_TRANSACTION_VERSION),
109 DP_STR(LINK_ADDRESS),
110 DP_STR(CONNECTION_STATUS_NOTIFY),
111 DP_STR(ENUM_PATH_RESOURCES),
112 DP_STR(ALLOCATE_PAYLOAD),
113 DP_STR(QUERY_PAYLOAD),
114 DP_STR(RESOURCE_STATUS_NOTIFY),
115 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
116 DP_STR(REMOTE_DPCD_READ),
117 DP_STR(REMOTE_DPCD_WRITE),
118 DP_STR(REMOTE_I2C_READ),
119 DP_STR(REMOTE_I2C_WRITE),
120 DP_STR(POWER_UP_PHY),
121 DP_STR(POWER_DOWN_PHY),
122 DP_STR(SINK_EVENT_NOTIFY),
123 DP_STR(QUERY_STREAM_ENC_STATUS),
126 if (req_type >= ARRAY_SIZE(req_type_str) ||
127 !req_type_str[req_type])
130 return req_type_str[req_type];
134 #define DP_STR(x) [DP_NAK_ ## x] = #x
136 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
138 static const char * const nak_reason_str[] = {
139 DP_STR(WRITE_FAILURE),
140 DP_STR(INVALID_READ),
144 DP_STR(LINK_FAILURE),
145 DP_STR(NO_RESOURCES),
148 DP_STR(ALLOCATE_FAIL),
151 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
152 !nak_reason_str[nak_reason])
155 return nak_reason_str[nak_reason];
159 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
161 static const char *drm_dp_mst_sideband_tx_state_str(int state)
163 static const char * const sideband_reason_str[] = {
171 if (state >= ARRAY_SIZE(sideband_reason_str) ||
172 !sideband_reason_str[state])
175 return sideband_reason_str[state];
179 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
184 for (i = 0; i < lct; i++) {
186 unpacked_rad[i] = rad[i / 2] >> 4;
188 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
191 /* TODO: Eventually add something to printk so we can format the rad
194 return snprintf(out, len, "%*phC", lct, unpacked_rad);
197 /* sideband msg handling */
198 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
203 int number_of_bits = num_nibbles * 4;
206 while (number_of_bits != 0) {
209 remainder |= (data[array_index] & bitmask) >> bitshift;
217 if ((remainder & 0x10) == 0x10)
222 while (number_of_bits != 0) {
225 if ((remainder & 0x10) != 0)
232 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
237 int number_of_bits = number_of_bytes * 8;
240 while (number_of_bits != 0) {
243 remainder |= (data[array_index] & bitmask) >> bitshift;
251 if ((remainder & 0x100) == 0x100)
256 while (number_of_bits != 0) {
259 if ((remainder & 0x100) != 0)
263 return remainder & 0xff;
265 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
269 size += (hdr->lct / 2);
273 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
280 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
281 for (i = 0; i < (hdr->lct / 2); i++)
282 buf[idx++] = hdr->rad[i];
283 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
284 (hdr->msg_len & 0x3f);
285 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
287 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
288 buf[idx - 1] |= (crc4 & 0xf);
293 static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr,
294 struct drm_dp_sideband_msg_hdr *hdr,
295 u8 *buf, int buflen, u8 *hdrlen)
305 len += ((buf[0] & 0xf0) >> 4) / 2;
308 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
310 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
311 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
315 hdr->lct = (buf[0] & 0xf0) >> 4;
316 hdr->lcr = (buf[0] & 0xf);
318 for (i = 0; i < (hdr->lct / 2); i++)
319 hdr->rad[i] = buf[idx++];
320 hdr->broadcast = (buf[idx] >> 7) & 0x1;
321 hdr->path_msg = (buf[idx] >> 6) & 0x1;
322 hdr->msg_len = buf[idx] & 0x3f;
324 hdr->somt = (buf[idx] >> 7) & 0x1;
325 hdr->eomt = (buf[idx] >> 6) & 0x1;
326 hdr->seqno = (buf[idx] >> 4) & 0x1;
333 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
334 struct drm_dp_sideband_msg_tx *raw)
340 buf[idx++] = req->req_type & 0x7f;
342 switch (req->req_type) {
343 case DP_ENUM_PATH_RESOURCES:
344 case DP_POWER_DOWN_PHY:
345 case DP_POWER_UP_PHY:
346 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
349 case DP_ALLOCATE_PAYLOAD:
350 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
351 (req->u.allocate_payload.number_sdp_streams & 0xf);
353 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
355 buf[idx] = (req->u.allocate_payload.pbn >> 8);
357 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
359 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
360 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
361 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
364 if (req->u.allocate_payload.number_sdp_streams & 1) {
365 i = req->u.allocate_payload.number_sdp_streams - 1;
366 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
370 case DP_QUERY_PAYLOAD:
371 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
373 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
376 case DP_REMOTE_DPCD_READ:
377 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
378 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
380 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
382 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
384 buf[idx] = (req->u.dpcd_read.num_bytes);
388 case DP_REMOTE_DPCD_WRITE:
389 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
390 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
392 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
394 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
396 buf[idx] = (req->u.dpcd_write.num_bytes);
398 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
399 idx += req->u.dpcd_write.num_bytes;
401 case DP_REMOTE_I2C_READ:
402 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
403 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
405 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
406 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
408 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
410 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
411 idx += req->u.i2c_read.transactions[i].num_bytes;
413 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
414 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
417 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
419 buf[idx] = (req->u.i2c_read.num_bytes_read);
423 case DP_REMOTE_I2C_WRITE:
424 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
426 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
428 buf[idx] = (req->u.i2c_write.num_bytes);
430 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
431 idx += req->u.i2c_write.num_bytes;
433 case DP_QUERY_STREAM_ENC_STATUS: {
434 const struct drm_dp_query_stream_enc_status *msg;
436 msg = &req->u.enc_status;
437 buf[idx] = msg->stream_id;
439 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
440 idx += sizeof(msg->client_id);
442 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
443 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
444 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
445 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
452 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
454 /* Decode a sideband request we've encoded, mainly used for debugging */
456 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
457 struct drm_dp_sideband_msg_req_body *req)
459 const u8 *buf = raw->msg;
462 req->req_type = buf[idx++] & 0x7f;
463 switch (req->req_type) {
464 case DP_ENUM_PATH_RESOURCES:
465 case DP_POWER_DOWN_PHY:
466 case DP_POWER_UP_PHY:
467 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
469 case DP_ALLOCATE_PAYLOAD:
471 struct drm_dp_allocate_payload *a =
472 &req->u.allocate_payload;
474 a->number_sdp_streams = buf[idx] & 0xf;
475 a->port_number = (buf[idx] >> 4) & 0xf;
477 WARN_ON(buf[++idx] & 0x80);
478 a->vcpi = buf[idx] & 0x7f;
480 a->pbn = buf[++idx] << 8;
481 a->pbn |= buf[++idx];
484 for (i = 0; i < a->number_sdp_streams; i++) {
485 a->sdp_stream_sink[i] =
486 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
490 case DP_QUERY_PAYLOAD:
491 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
492 WARN_ON(buf[++idx] & 0x80);
493 req->u.query_payload.vcpi = buf[idx] & 0x7f;
495 case DP_REMOTE_DPCD_READ:
497 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
499 r->port_number = (buf[idx] >> 4) & 0xf;
501 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
502 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
503 r->dpcd_address |= buf[++idx] & 0xff;
505 r->num_bytes = buf[++idx];
508 case DP_REMOTE_DPCD_WRITE:
510 struct drm_dp_remote_dpcd_write *w =
513 w->port_number = (buf[idx] >> 4) & 0xf;
515 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
516 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
517 w->dpcd_address |= buf[++idx] & 0xff;
519 w->num_bytes = buf[++idx];
521 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
527 case DP_REMOTE_I2C_READ:
529 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
530 struct drm_dp_remote_i2c_read_tx *tx;
533 r->num_transactions = buf[idx] & 0x3;
534 r->port_number = (buf[idx] >> 4) & 0xf;
535 for (i = 0; i < r->num_transactions; i++) {
536 tx = &r->transactions[i];
538 tx->i2c_dev_id = buf[++idx] & 0x7f;
539 tx->num_bytes = buf[++idx];
540 tx->bytes = kmemdup(&buf[++idx],
547 idx += tx->num_bytes;
548 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
549 tx->i2c_transaction_delay = buf[idx] & 0xf;
553 for (i = 0; i < r->num_transactions; i++) {
554 tx = &r->transactions[i];
560 r->read_i2c_device_id = buf[++idx] & 0x7f;
561 r->num_bytes_read = buf[++idx];
564 case DP_REMOTE_I2C_WRITE:
566 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
568 w->port_number = (buf[idx] >> 4) & 0xf;
569 w->write_i2c_device_id = buf[++idx] & 0x7f;
570 w->num_bytes = buf[++idx];
571 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
577 case DP_QUERY_STREAM_ENC_STATUS:
578 req->u.enc_status.stream_id = buf[idx++];
579 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
580 req->u.enc_status.client_id[i] = buf[idx++];
582 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
584 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
586 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
588 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
595 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
598 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
599 int indent, struct drm_printer *printer)
603 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
604 if (req->req_type == DP_LINK_ADDRESS) {
605 /* No contents to print */
606 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
610 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
613 switch (req->req_type) {
614 case DP_ENUM_PATH_RESOURCES:
615 case DP_POWER_DOWN_PHY:
616 case DP_POWER_UP_PHY:
617 P("port=%d\n", req->u.port_num.port_number);
619 case DP_ALLOCATE_PAYLOAD:
620 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
621 req->u.allocate_payload.port_number,
622 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
623 req->u.allocate_payload.number_sdp_streams,
624 req->u.allocate_payload.number_sdp_streams,
625 req->u.allocate_payload.sdp_stream_sink);
627 case DP_QUERY_PAYLOAD:
628 P("port=%d vcpi=%d\n",
629 req->u.query_payload.port_number,
630 req->u.query_payload.vcpi);
632 case DP_REMOTE_DPCD_READ:
633 P("port=%d dpcd_addr=%05x len=%d\n",
634 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
635 req->u.dpcd_read.num_bytes);
637 case DP_REMOTE_DPCD_WRITE:
638 P("port=%d addr=%05x len=%d: %*ph\n",
639 req->u.dpcd_write.port_number,
640 req->u.dpcd_write.dpcd_address,
641 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
642 req->u.dpcd_write.bytes);
644 case DP_REMOTE_I2C_READ:
645 P("port=%d num_tx=%d id=%d size=%d:\n",
646 req->u.i2c_read.port_number,
647 req->u.i2c_read.num_transactions,
648 req->u.i2c_read.read_i2c_device_id,
649 req->u.i2c_read.num_bytes_read);
652 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
653 const struct drm_dp_remote_i2c_read_tx *rtx =
654 &req->u.i2c_read.transactions[i];
656 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
657 i, rtx->i2c_dev_id, rtx->num_bytes,
658 rtx->no_stop_bit, rtx->i2c_transaction_delay,
659 rtx->num_bytes, rtx->bytes);
662 case DP_REMOTE_I2C_WRITE:
663 P("port=%d id=%d size=%d: %*ph\n",
664 req->u.i2c_write.port_number,
665 req->u.i2c_write.write_i2c_device_id,
666 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
667 req->u.i2c_write.bytes);
669 case DP_QUERY_STREAM_ENC_STATUS:
670 P("stream_id=%u client_id=%*ph stream_event=%x "
671 "valid_event=%d stream_behavior=%x valid_behavior=%d",
672 req->u.enc_status.stream_id,
673 (int)ARRAY_SIZE(req->u.enc_status.client_id),
674 req->u.enc_status.client_id, req->u.enc_status.stream_event,
675 req->u.enc_status.valid_stream_event,
676 req->u.enc_status.stream_behavior,
677 req->u.enc_status.valid_stream_behavior);
685 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
688 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
689 const struct drm_dp_sideband_msg_tx *txmsg)
691 struct drm_dp_sideband_msg_req_body req;
696 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
698 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
699 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
700 drm_dp_mst_sideband_tx_state_str(txmsg->state),
701 txmsg->path_msg, buf);
703 ret = drm_dp_decode_sideband_req(txmsg, &req);
705 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
708 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
710 switch (req.req_type) {
711 case DP_REMOTE_DPCD_WRITE:
712 kfree(req.u.dpcd_write.bytes);
714 case DP_REMOTE_I2C_READ:
715 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
716 kfree(req.u.i2c_read.transactions[i].bytes);
718 case DP_REMOTE_I2C_WRITE:
719 kfree(req.u.i2c_write.bytes);
724 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
728 crc4 = drm_dp_msg_data_crc4(msg, len);
732 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
733 struct drm_dp_sideband_msg_tx *raw)
738 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
743 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
744 struct drm_dp_sideband_msg_hdr *hdr,
748 * ignore out-of-order messages or messages that are part of a
751 if (!hdr->somt && !msg->have_somt)
754 /* get length contained in this portion */
755 msg->curchunk_idx = 0;
756 msg->curchunk_len = hdr->msg_len;
757 msg->curchunk_hdrlen = hdrlen;
759 /* we have already gotten an somt - don't bother parsing */
760 if (hdr->somt && msg->have_somt)
764 memcpy(&msg->initial_hdr, hdr,
765 sizeof(struct drm_dp_sideband_msg_hdr));
766 msg->have_somt = true;
769 msg->have_eomt = true;
774 /* this adds a chunk of msg to the builder to get the final msg */
775 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
776 u8 *replybuf, u8 replybuflen)
780 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
781 msg->curchunk_idx += replybuflen;
783 if (msg->curchunk_idx >= msg->curchunk_len) {
785 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
786 if (crc4 != msg->chunk[msg->curchunk_len - 1])
787 print_hex_dump(KERN_DEBUG, "wrong crc",
788 DUMP_PREFIX_NONE, 16, 1,
789 msg->chunk, msg->curchunk_len, false);
790 /* copy chunk into bigger msg */
791 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
792 msg->curlen += msg->curchunk_len - 1;
797 static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr,
798 struct drm_dp_sideband_msg_rx *raw,
799 struct drm_dp_sideband_msg_reply_body *repmsg)
804 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
806 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
808 if (idx > raw->curlen)
810 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
811 if (raw->msg[idx] & 0x80)
812 repmsg->u.link_addr.ports[i].input_port = 1;
814 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
815 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
818 if (idx > raw->curlen)
820 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
821 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
822 if (repmsg->u.link_addr.ports[i].input_port == 0)
823 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
825 if (idx > raw->curlen)
827 if (repmsg->u.link_addr.ports[i].input_port == 0) {
828 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
830 if (idx > raw->curlen)
832 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
834 if (idx > raw->curlen)
836 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
837 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
841 if (idx > raw->curlen)
847 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
851 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
852 struct drm_dp_sideband_msg_reply_body *repmsg)
856 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
858 if (idx > raw->curlen)
860 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
862 if (idx > raw->curlen)
865 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
868 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
872 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
873 struct drm_dp_sideband_msg_reply_body *repmsg)
877 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
879 if (idx > raw->curlen)
883 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
887 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
888 struct drm_dp_sideband_msg_reply_body *repmsg)
892 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
894 if (idx > raw->curlen)
896 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
899 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
902 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
906 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
907 struct drm_dp_sideband_msg_reply_body *repmsg)
911 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
912 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
914 if (idx > raw->curlen)
916 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
918 if (idx > raw->curlen)
920 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
922 if (idx > raw->curlen)
926 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
930 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
931 struct drm_dp_sideband_msg_reply_body *repmsg)
935 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
937 if (idx > raw->curlen)
939 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
941 if (idx > raw->curlen)
943 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
945 if (idx > raw->curlen)
949 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
953 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
954 struct drm_dp_sideband_msg_reply_body *repmsg)
958 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
960 if (idx > raw->curlen)
962 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
964 if (idx > raw->curlen)
968 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
972 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
973 struct drm_dp_sideband_msg_reply_body *repmsg)
977 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
979 if (idx > raw->curlen) {
980 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
988 drm_dp_sideband_parse_query_stream_enc_status(
989 struct drm_dp_sideband_msg_rx *raw,
990 struct drm_dp_sideband_msg_reply_body *repmsg)
992 struct drm_dp_query_stream_enc_status_ack_reply *reply;
994 reply = &repmsg->u.enc_status;
996 reply->stream_id = raw->msg[3];
998 reply->reply_signed = raw->msg[2] & BIT(0);
1001 * NOTE: It's my impression from reading the spec that the below parsing
1002 * is correct. However I noticed while testing with an HDCP 1.4 display
1003 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I
1004 * would expect both bits to be set. So keep the parsing following the
1005 * spec, but beware reality might not match the spec (at least for some
1008 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4);
1009 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3);
1011 reply->query_capable_device_present = raw->msg[2] & BIT(5);
1012 reply->legacy_device_present = raw->msg[2] & BIT(6);
1013 reply->unauthorizable_device_present = raw->msg[2] & BIT(7);
1015 reply->auth_completed = !!(raw->msg[1] & BIT(3));
1016 reply->encryption_enabled = !!(raw->msg[1] & BIT(4));
1017 reply->repeater_present = !!(raw->msg[1] & BIT(5));
1018 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6;
1023 static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr,
1024 struct drm_dp_sideband_msg_rx *raw,
1025 struct drm_dp_sideband_msg_reply_body *msg)
1027 memset(msg, 0, sizeof(*msg));
1028 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
1029 msg->req_type = (raw->msg[0] & 0x7f);
1031 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
1032 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
1033 msg->u.nak.reason = raw->msg[17];
1034 msg->u.nak.nak_data = raw->msg[18];
1038 switch (msg->req_type) {
1039 case DP_LINK_ADDRESS:
1040 return drm_dp_sideband_parse_link_address(mgr, raw, msg);
1041 case DP_QUERY_PAYLOAD:
1042 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
1043 case DP_REMOTE_DPCD_READ:
1044 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
1045 case DP_REMOTE_DPCD_WRITE:
1046 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
1047 case DP_REMOTE_I2C_READ:
1048 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
1049 case DP_REMOTE_I2C_WRITE:
1050 return true; /* since there's nothing to parse */
1051 case DP_ENUM_PATH_RESOURCES:
1052 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
1053 case DP_ALLOCATE_PAYLOAD:
1054 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
1055 case DP_POWER_DOWN_PHY:
1056 case DP_POWER_UP_PHY:
1057 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
1058 case DP_CLEAR_PAYLOAD_ID_TABLE:
1059 return true; /* since there's nothing to parse */
1060 case DP_QUERY_STREAM_ENC_STATUS:
1061 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg);
1063 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n",
1064 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1070 drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1071 struct drm_dp_sideband_msg_rx *raw,
1072 struct drm_dp_sideband_msg_req_body *msg)
1076 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1078 if (idx > raw->curlen)
1081 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
1083 if (idx > raw->curlen)
1086 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
1087 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
1088 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
1089 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
1090 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1094 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n",
1099 static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1100 struct drm_dp_sideband_msg_rx *raw,
1101 struct drm_dp_sideband_msg_req_body *msg)
1105 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1107 if (idx > raw->curlen)
1110 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1112 if (idx > raw->curlen)
1115 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1119 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen);
1123 static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
1124 struct drm_dp_sideband_msg_rx *raw,
1125 struct drm_dp_sideband_msg_req_body *msg)
1127 memset(msg, 0, sizeof(*msg));
1128 msg->req_type = (raw->msg[0] & 0x7f);
1130 switch (msg->req_type) {
1131 case DP_CONNECTION_STATUS_NOTIFY:
1132 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg);
1133 case DP_RESOURCE_STATUS_NOTIFY:
1134 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg);
1136 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n",
1137 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1142 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1143 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1145 struct drm_dp_sideband_msg_req_body req;
1147 req.req_type = DP_REMOTE_DPCD_WRITE;
1148 req.u.dpcd_write.port_number = port_num;
1149 req.u.dpcd_write.dpcd_address = offset;
1150 req.u.dpcd_write.num_bytes = num_bytes;
1151 req.u.dpcd_write.bytes = bytes;
1152 drm_dp_encode_sideband_req(&req, msg);
1155 static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1157 struct drm_dp_sideband_msg_req_body req;
1159 req.req_type = DP_LINK_ADDRESS;
1160 drm_dp_encode_sideband_req(&req, msg);
1163 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1165 struct drm_dp_sideband_msg_req_body req;
1167 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1168 drm_dp_encode_sideband_req(&req, msg);
1169 msg->path_msg = true;
1172 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1175 struct drm_dp_sideband_msg_req_body req;
1177 req.req_type = DP_ENUM_PATH_RESOURCES;
1178 req.u.port_num.port_number = port_num;
1179 drm_dp_encode_sideband_req(&req, msg);
1180 msg->path_msg = true;
1184 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1186 u8 vcpi, uint16_t pbn,
1187 u8 number_sdp_streams,
1188 u8 *sdp_stream_sink)
1190 struct drm_dp_sideband_msg_req_body req;
1192 memset(&req, 0, sizeof(req));
1193 req.req_type = DP_ALLOCATE_PAYLOAD;
1194 req.u.allocate_payload.port_number = port_num;
1195 req.u.allocate_payload.vcpi = vcpi;
1196 req.u.allocate_payload.pbn = pbn;
1197 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1198 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1199 number_sdp_streams);
1200 drm_dp_encode_sideband_req(&req, msg);
1201 msg->path_msg = true;
1204 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1205 int port_num, bool power_up)
1207 struct drm_dp_sideband_msg_req_body req;
1210 req.req_type = DP_POWER_UP_PHY;
1212 req.req_type = DP_POWER_DOWN_PHY;
1214 req.u.port_num.port_number = port_num;
1215 drm_dp_encode_sideband_req(&req, msg);
1216 msg->path_msg = true;
1220 build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id,
1223 struct drm_dp_sideband_msg_req_body req;
1225 req.req_type = DP_QUERY_STREAM_ENC_STATUS;
1226 req.u.enc_status.stream_id = stream_id;
1227 memcpy(req.u.enc_status.client_id, q_id,
1228 sizeof(req.u.enc_status.client_id));
1229 req.u.enc_status.stream_event = 0;
1230 req.u.enc_status.valid_stream_event = false;
1231 req.u.enc_status.stream_behavior = 0;
1232 req.u.enc_status.valid_stream_behavior = false;
1234 drm_dp_encode_sideband_req(&req, msg);
1238 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1239 struct drm_dp_sideband_msg_tx *txmsg)
1244 * All updates to txmsg->state are protected by mgr->qlock, and the two
1245 * cases we check here are terminal states. For those the barriers
1246 * provided by the wake_up/wait_event pair are enough.
1248 state = READ_ONCE(txmsg->state);
1249 return (state == DRM_DP_SIDEBAND_TX_RX ||
1250 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1253 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1254 struct drm_dp_sideband_msg_tx *txmsg)
1256 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1257 unsigned long wait_timeout = msecs_to_jiffies(4000);
1258 unsigned long wait_expires = jiffies + wait_timeout;
1263 * If the driver provides a way for this, change to
1264 * poll-waiting for the MST reply interrupt if we didn't receive
1265 * it for 50 msec. This would cater for cases where the HPD
1266 * pulse signal got lost somewhere, even though the sink raised
1267 * the corresponding MST interrupt correctly. One example is the
1268 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1269 * filters out short pulses with a duration less than ~540 usec.
1271 * The poll period is 50 msec to avoid missing an interrupt
1272 * after the sink has cleared it (after a 110msec timeout
1273 * since it raised the interrupt).
1275 ret = wait_event_timeout(mgr->tx_waitq,
1276 check_txmsg_state(mgr, txmsg),
1277 mgr->cbs->poll_hpd_irq ?
1278 msecs_to_jiffies(50) :
1281 if (ret || !mgr->cbs->poll_hpd_irq ||
1282 time_after(jiffies, wait_expires))
1285 mgr->cbs->poll_hpd_irq(mgr);
1288 mutex_lock(&mgr->qlock);
1290 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1295 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n",
1296 txmsg, txmsg->state, txmsg->seqno);
1298 /* dump some state */
1302 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1303 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1304 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1305 list_del(&txmsg->next);
1308 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1309 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1311 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1313 mutex_unlock(&mgr->qlock);
1315 drm_dp_mst_kick_tx(mgr);
1319 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1321 struct drm_dp_mst_branch *mstb;
1323 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1329 memcpy(mstb->rad, rad, lct / 2);
1330 INIT_LIST_HEAD(&mstb->ports);
1331 kref_init(&mstb->topology_kref);
1332 kref_init(&mstb->malloc_kref);
1336 static void drm_dp_free_mst_branch_device(struct kref *kref)
1338 struct drm_dp_mst_branch *mstb =
1339 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1341 if (mstb->port_parent)
1342 drm_dp_mst_put_port_malloc(mstb->port_parent);
1348 * DOC: Branch device and port refcounting
1350 * Topology refcount overview
1351 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1353 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1354 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1355 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1357 * Topology refcounts are not exposed to drivers, and are handled internally
1358 * by the DP MST helpers. The helpers use them in order to prevent the
1359 * in-memory topology state from being changed in the middle of critical
1360 * operations like changing the internal state of payload allocations. This
1361 * means each branch and port will be considered to be connected to the rest
1362 * of the topology until its topology refcount reaches zero. Additionally,
1363 * for ports this means that their associated &struct drm_connector will stay
1364 * registered with userspace until the port's refcount reaches 0.
1366 * Malloc refcount overview
1367 * ~~~~~~~~~~~~~~~~~~~~~~~~
1369 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1370 * drm_dp_mst_branch allocated even after all of its topology references have
1371 * been dropped, so that the driver or MST helpers can safely access each
1372 * branch's last known state before it was disconnected from the topology.
1373 * When the malloc refcount of a port or branch reaches 0, the memory
1374 * allocation containing the &struct drm_dp_mst_branch or &struct
1375 * drm_dp_mst_port respectively will be freed.
1377 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1378 * to drivers. As of writing this documentation, there are no drivers that
1379 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1380 * helpers. Exposing this API to drivers in a race-free manner would take more
1381 * tweaking of the refcounting scheme, however patches are welcome provided
1382 * there is a legitimate driver usecase for this.
1384 * Refcount relationships in a topology
1385 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1387 * Let's take a look at why the relationship between topology and malloc
1388 * refcounts is designed the way it is.
1390 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1392 * An example of topology and malloc refs in a DP MST topology with two
1393 * active payloads. Topology refcount increments are indicated by solid
1394 * lines, and malloc refcount increments are indicated by dashed lines.
1395 * Each starts from the branch which incremented the refcount, and ends at
1396 * the branch to which the refcount belongs to, i.e. the arrow points the
1397 * same way as the C pointers used to reference a structure.
1399 * As you can see in the above figure, every branch increments the topology
1400 * refcount of its children, and increments the malloc refcount of its
1401 * parent. Additionally, every payload increments the malloc refcount of its
1402 * assigned port by 1.
1404 * So, what would happen if MSTB #3 from the above figure was unplugged from
1405 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1406 * topology would start to look like the figure below.
1408 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1410 * Ports and branch devices which have been released from memory are
1411 * colored grey, and references which have been removed are colored red.
1413 * Whenever a port or branch device's topology refcount reaches zero, it will
1414 * decrement the topology refcounts of all its children, the malloc refcount
1415 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1416 * #4, this means they both have been disconnected from the topology and freed
1417 * from memory. But, because payload #2 is still holding a reference to port
1418 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1419 * is still accessible from memory. This also means port #3 has not yet
1420 * decremented the malloc refcount of MSTB #3, so its &struct
1421 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1422 * malloc refcount reaches 0.
1424 * This relationship is necessary because in order to release payload #2, we
1425 * need to be able to figure out the last relative of port #3 that's still
1426 * connected to the topology. In this case, we would travel up the topology as
1429 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1431 * And finally, remove payload #2 by communicating with port #2 through
1432 * sideband transactions.
1436 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1438 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1440 * Increments &drm_dp_mst_branch.malloc_kref. When
1441 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1442 * will be released and @mstb may no longer be used.
1444 * See also: drm_dp_mst_put_mstb_malloc()
1447 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1449 kref_get(&mstb->malloc_kref);
1450 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1454 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1456 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1458 * Decrements &drm_dp_mst_branch.malloc_kref. When
1459 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1460 * will be released and @mstb may no longer be used.
1462 * See also: drm_dp_mst_get_mstb_malloc()
1465 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1467 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1468 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1471 static void drm_dp_free_mst_port(struct kref *kref)
1473 struct drm_dp_mst_port *port =
1474 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1476 drm_dp_mst_put_mstb_malloc(port->parent);
1481 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1482 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1484 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1485 * reaches 0, the memory allocation for @port will be released and @port may
1486 * no longer be used.
1488 * Because @port could potentially be freed at any time by the DP MST helpers
1489 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1490 * function, drivers that which to make use of &struct drm_dp_mst_port should
1491 * ensure that they grab at least one main malloc reference to their MST ports
1492 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1493 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1495 * See also: drm_dp_mst_put_port_malloc()
1498 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1500 kref_get(&port->malloc_kref);
1501 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref));
1503 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1506 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1507 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1509 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1510 * reaches 0, the memory allocation for @port will be released and @port may
1511 * no longer be used.
1513 * See also: drm_dp_mst_get_port_malloc()
1516 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1518 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1519 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1521 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1523 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1525 #define STACK_DEPTH 8
1527 static noinline void
1528 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1529 struct drm_dp_mst_topology_ref_history *history,
1530 enum drm_dp_mst_topology_ref_type type)
1532 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1533 depot_stack_handle_t backtrace;
1534 ulong stack_entries[STACK_DEPTH];
1538 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1539 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1543 /* Try to find an existing entry for this backtrace */
1544 for (i = 0; i < history->len; i++) {
1545 if (history->entries[i].backtrace == backtrace) {
1546 entry = &history->entries[i];
1551 /* Otherwise add one */
1553 struct drm_dp_mst_topology_ref_entry *new;
1554 int new_len = history->len + 1;
1556 new = krealloc(history->entries, sizeof(*new) * new_len,
1561 entry = &new[history->len];
1562 history->len = new_len;
1563 history->entries = new;
1565 entry->backtrace = backtrace;
1570 entry->ts_nsec = ktime_get_ns();
1574 topology_ref_history_cmp(const void *a, const void *b)
1576 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1578 if (entry_a->ts_nsec > entry_b->ts_nsec)
1580 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1586 static inline const char *
1587 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1589 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1596 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1597 void *ptr, const char *type_str)
1599 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1600 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1609 /* First, sort the list so that it goes from oldest to newest
1612 sort(history->entries, history->len, sizeof(*history->entries),
1613 topology_ref_history_cmp, NULL);
1615 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1618 for (i = 0; i < history->len; i++) {
1619 const struct drm_dp_mst_topology_ref_entry *entry =
1620 &history->entries[i];
1621 u64 ts_nsec = entry->ts_nsec;
1622 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1624 stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4);
1626 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1628 topology_ref_type_to_str(entry->type),
1629 ts_nsec, rem_nsec / 1000, buf);
1632 /* Now free the history, since this is the only time we expose it */
1633 kfree(history->entries);
1638 static __always_inline void
1639 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1641 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1645 static __always_inline void
1646 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1648 __dump_topology_ref_history(&port->topology_ref_history, port,
1652 static __always_inline void
1653 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1654 enum drm_dp_mst_topology_ref_type type)
1656 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1659 static __always_inline void
1660 save_port_topology_ref(struct drm_dp_mst_port *port,
1661 enum drm_dp_mst_topology_ref_type type)
1663 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1667 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1669 mutex_lock(&mgr->topology_ref_history_lock);
1673 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1675 mutex_unlock(&mgr->topology_ref_history_lock);
1679 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1681 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1683 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1685 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1686 #define save_mstb_topology_ref(mstb, type)
1687 #define save_port_topology_ref(port, type)
1690 struct drm_dp_mst_atomic_payload *
1691 drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state,
1692 struct drm_dp_mst_port *port)
1694 struct drm_dp_mst_atomic_payload *payload;
1696 list_for_each_entry(payload, &state->payloads, next)
1697 if (payload->port == port)
1702 EXPORT_SYMBOL(drm_atomic_get_mst_payload_state);
1704 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1706 struct drm_dp_mst_branch *mstb =
1707 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1708 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1710 drm_dp_mst_dump_mstb_topology_history(mstb);
1712 INIT_LIST_HEAD(&mstb->destroy_next);
1715 * This can get called under mgr->mutex, so we need to perform the
1716 * actual destruction of the mstb in another worker
1718 mutex_lock(&mgr->delayed_destroy_lock);
1719 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1720 mutex_unlock(&mgr->delayed_destroy_lock);
1721 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1725 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1726 * branch device unless it's zero
1727 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1729 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1730 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1731 * reached 0). Holding a topology reference implies that a malloc reference
1732 * will be held to @mstb as long as the user holds the topology reference.
1734 * Care should be taken to ensure that the user has at least one malloc
1735 * reference to @mstb. If you already have a topology reference to @mstb, you
1736 * should use drm_dp_mst_topology_get_mstb() instead.
1739 * drm_dp_mst_topology_get_mstb()
1740 * drm_dp_mst_topology_put_mstb()
1743 * * 1: A topology reference was grabbed successfully
1744 * * 0: @port is no longer in the topology, no reference was grabbed
1746 static int __must_check
1747 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1751 topology_ref_history_lock(mstb->mgr);
1752 ret = kref_get_unless_zero(&mstb->topology_kref);
1754 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1755 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1758 topology_ref_history_unlock(mstb->mgr);
1764 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1766 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1768 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1769 * not it's already reached 0. This is only valid to use in scenarios where
1770 * you are already guaranteed to have at least one active topology reference
1771 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1774 * drm_dp_mst_topology_try_get_mstb()
1775 * drm_dp_mst_topology_put_mstb()
1777 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1779 topology_ref_history_lock(mstb->mgr);
1781 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1782 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1783 kref_get(&mstb->topology_kref);
1784 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1786 topology_ref_history_unlock(mstb->mgr);
1790 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1792 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1794 * Releases a topology reference from @mstb by decrementing
1795 * &drm_dp_mst_branch.topology_kref.
1798 * drm_dp_mst_topology_try_get_mstb()
1799 * drm_dp_mst_topology_get_mstb()
1802 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1804 topology_ref_history_lock(mstb->mgr);
1806 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1);
1807 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1809 topology_ref_history_unlock(mstb->mgr);
1810 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1813 static void drm_dp_destroy_port(struct kref *kref)
1815 struct drm_dp_mst_port *port =
1816 container_of(kref, struct drm_dp_mst_port, topology_kref);
1817 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1819 drm_dp_mst_dump_port_topology_history(port);
1821 /* There's nothing that needs locking to destroy an input port yet */
1823 drm_dp_mst_put_port_malloc(port);
1827 drm_edid_free(port->cached_edid);
1830 * we can't destroy the connector here, as we might be holding the
1831 * mode_config.mutex from an EDID retrieval
1833 mutex_lock(&mgr->delayed_destroy_lock);
1834 list_add(&port->next, &mgr->destroy_port_list);
1835 mutex_unlock(&mgr->delayed_destroy_lock);
1836 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1840 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1841 * port unless it's zero
1842 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1844 * Attempts to grab a topology reference to @port, if it hasn't yet been
1845 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1846 * 0). Holding a topology reference implies that a malloc reference will be
1847 * held to @port as long as the user holds the topology reference.
1849 * Care should be taken to ensure that the user has at least one malloc
1850 * reference to @port. If you already have a topology reference to @port, you
1851 * should use drm_dp_mst_topology_get_port() instead.
1854 * drm_dp_mst_topology_get_port()
1855 * drm_dp_mst_topology_put_port()
1858 * * 1: A topology reference was grabbed successfully
1859 * * 0: @port is no longer in the topology, no reference was grabbed
1861 static int __must_check
1862 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1866 topology_ref_history_lock(port->mgr);
1867 ret = kref_get_unless_zero(&port->topology_kref);
1869 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1870 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1873 topology_ref_history_unlock(port->mgr);
1878 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1879 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1881 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1882 * not it's already reached 0. This is only valid to use in scenarios where
1883 * you are already guaranteed to have at least one active topology reference
1884 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1887 * drm_dp_mst_topology_try_get_port()
1888 * drm_dp_mst_topology_put_port()
1890 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1892 topology_ref_history_lock(port->mgr);
1894 WARN_ON(kref_read(&port->topology_kref) == 0);
1895 kref_get(&port->topology_kref);
1896 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1897 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1899 topology_ref_history_unlock(port->mgr);
1903 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1904 * @port: The &struct drm_dp_mst_port to release the topology reference from
1906 * Releases a topology reference from @port by decrementing
1907 * &drm_dp_mst_port.topology_kref.
1910 * drm_dp_mst_topology_try_get_port()
1911 * drm_dp_mst_topology_get_port()
1913 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1915 topology_ref_history_lock(port->mgr);
1917 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1);
1918 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1920 topology_ref_history_unlock(port->mgr);
1921 kref_put(&port->topology_kref, drm_dp_destroy_port);
1924 static struct drm_dp_mst_branch *
1925 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1926 struct drm_dp_mst_branch *to_find)
1928 struct drm_dp_mst_port *port;
1929 struct drm_dp_mst_branch *rmstb;
1931 if (to_find == mstb)
1934 list_for_each_entry(port, &mstb->ports, next) {
1936 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1937 port->mstb, to_find);
1945 static struct drm_dp_mst_branch *
1946 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1947 struct drm_dp_mst_branch *mstb)
1949 struct drm_dp_mst_branch *rmstb = NULL;
1951 mutex_lock(&mgr->lock);
1952 if (mgr->mst_primary) {
1953 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1954 mgr->mst_primary, mstb);
1956 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1959 mutex_unlock(&mgr->lock);
1963 static struct drm_dp_mst_port *
1964 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1965 struct drm_dp_mst_port *to_find)
1967 struct drm_dp_mst_port *port, *mport;
1969 list_for_each_entry(port, &mstb->ports, next) {
1970 if (port == to_find)
1974 mport = drm_dp_mst_topology_get_port_validated_locked(
1975 port->mstb, to_find);
1983 static struct drm_dp_mst_port *
1984 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1985 struct drm_dp_mst_port *port)
1987 struct drm_dp_mst_port *rport = NULL;
1989 mutex_lock(&mgr->lock);
1990 if (mgr->mst_primary) {
1991 rport = drm_dp_mst_topology_get_port_validated_locked(
1992 mgr->mst_primary, port);
1994 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1997 mutex_unlock(&mgr->lock);
2001 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
2003 struct drm_dp_mst_port *port;
2006 list_for_each_entry(port, &mstb->ports, next) {
2007 if (port->port_num == port_num) {
2008 ret = drm_dp_mst_topology_try_get_port(port);
2009 return ret ? port : NULL;
2017 * calculate a new RAD for this MST branch device
2018 * if parent has an LCT of 2 then it has 1 nibble of RAD,
2019 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
2021 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
2024 int parent_lct = port->parent->lct;
2026 int idx = (parent_lct - 1) / 2;
2028 if (parent_lct > 1) {
2029 memcpy(rad, port->parent->rad, idx + 1);
2030 shift = (parent_lct % 2) ? 4 : 0;
2034 rad[idx] |= port->port_num << shift;
2035 return parent_lct + 1;
2038 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
2041 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2042 case DP_PEER_DEVICE_SST_SINK:
2044 case DP_PEER_DEVICE_MST_BRANCHING:
2045 /* For sst branch device */
2055 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
2058 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2059 struct drm_dp_mst_branch *mstb;
2063 if (port->pdt == new_pdt && port->mcs == new_mcs)
2066 /* Teardown the old pdt, if there is one */
2067 if (port->pdt != DP_PEER_DEVICE_NONE) {
2068 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2070 * If the new PDT would also have an i2c bus,
2071 * don't bother with reregistering it
2073 if (new_pdt != DP_PEER_DEVICE_NONE &&
2074 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2075 port->pdt = new_pdt;
2076 port->mcs = new_mcs;
2080 /* remove i2c over sideband */
2081 drm_dp_mst_unregister_i2c_bus(port);
2083 mutex_lock(&mgr->lock);
2084 drm_dp_mst_topology_put_mstb(port->mstb);
2086 mutex_unlock(&mgr->lock);
2090 port->pdt = new_pdt;
2091 port->mcs = new_mcs;
2093 if (port->pdt != DP_PEER_DEVICE_NONE) {
2094 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2095 /* add i2c over sideband */
2096 ret = drm_dp_mst_register_i2c_bus(port);
2098 lct = drm_dp_calculate_rad(port, rad);
2099 mstb = drm_dp_add_mst_branch_device(lct, rad);
2102 drm_err(mgr->dev, "Failed to create MSTB for port %p", port);
2106 mutex_lock(&mgr->lock);
2108 mstb->mgr = port->mgr;
2109 mstb->port_parent = port;
2112 * Make sure this port's memory allocation stays
2113 * around until its child MSTB releases it
2115 drm_dp_mst_get_port_malloc(port);
2116 mutex_unlock(&mgr->lock);
2118 /* And make sure we send a link address for this */
2125 port->pdt = DP_PEER_DEVICE_NONE;
2130 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2131 * @aux: Fake sideband AUX CH
2132 * @offset: address of the (first) register to read
2133 * @buffer: buffer to store the register values
2134 * @size: number of bytes in @buffer
2136 * Performs the same functionality for remote devices via
2137 * sideband messaging as drm_dp_dpcd_read() does for local
2138 * devices via actual AUX CH.
2140 * Return: Number of bytes read, or negative error code on failure.
2142 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2143 unsigned int offset, void *buffer, size_t size)
2145 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2148 return drm_dp_send_dpcd_read(port->mgr, port,
2149 offset, size, buffer);
2153 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2154 * @aux: Fake sideband AUX CH
2155 * @offset: address of the (first) register to write
2156 * @buffer: buffer containing the values to write
2157 * @size: number of bytes in @buffer
2159 * Performs the same functionality for remote devices via
2160 * sideband messaging as drm_dp_dpcd_write() does for local
2161 * devices via actual AUX CH.
2163 * Return: number of bytes written on success, negative error code on failure.
2165 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2166 unsigned int offset, void *buffer, size_t size)
2168 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2171 return drm_dp_send_dpcd_write(port->mgr, port,
2172 offset, size, buffer);
2175 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2179 memcpy(mstb->guid, guid, 16);
2181 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2182 if (mstb->port_parent) {
2183 ret = drm_dp_send_dpcd_write(mstb->mgr,
2185 DP_GUID, 16, mstb->guid);
2187 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2188 DP_GUID, mstb->guid, 16);
2192 if (ret < 16 && ret > 0)
2195 return ret == 16 ? 0 : ret;
2198 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2201 size_t proppath_size)
2206 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2207 for (i = 0; i < (mstb->lct - 1); i++) {
2208 int shift = (i % 2) ? 0 : 4;
2209 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2211 snprintf(temp, sizeof(temp), "-%d", port_num);
2212 strlcat(proppath, temp, proppath_size);
2214 snprintf(temp, sizeof(temp), "-%d", pnum);
2215 strlcat(proppath, temp, proppath_size);
2219 * drm_dp_mst_connector_late_register() - Late MST connector registration
2220 * @connector: The MST connector
2221 * @port: The MST port for this connector
2223 * Helper to register the remote aux device for this MST port. Drivers should
2224 * call this from their mst connector's late_register hook to enable MST aux
2227 * Return: 0 on success, negative error code on failure.
2229 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2230 struct drm_dp_mst_port *port)
2232 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n",
2233 port->aux.name, connector->kdev->kobj.name);
2235 port->aux.dev = connector->kdev;
2236 return drm_dp_aux_register_devnode(&port->aux);
2238 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2241 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2242 * @connector: The MST connector
2243 * @port: The MST port for this connector
2245 * Helper to unregister the remote aux device for this MST port, registered by
2246 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2247 * connector's early_unregister hook.
2249 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2250 struct drm_dp_mst_port *port)
2252 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n",
2253 port->aux.name, connector->kdev->kobj.name);
2254 drm_dp_aux_unregister_devnode(&port->aux);
2256 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2259 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2260 struct drm_dp_mst_port *port)
2262 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2266 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2267 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2268 if (!port->connector) {
2273 if (port->pdt != DP_PEER_DEVICE_NONE &&
2274 drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
2275 port->port_num >= DP_MST_LOGICAL_PORT_0)
2276 port->cached_edid = drm_edid_read_ddc(port->connector,
2279 drm_connector_register(port->connector);
2283 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret);
2287 * Drop a topology reference, and unlink the port from the in-memory topology
2291 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2292 struct drm_dp_mst_port *port)
2294 mutex_lock(&mgr->lock);
2295 port->parent->num_ports--;
2296 list_del(&port->next);
2297 mutex_unlock(&mgr->lock);
2298 drm_dp_mst_topology_put_port(port);
2301 static struct drm_dp_mst_port *
2302 drm_dp_mst_add_port(struct drm_device *dev,
2303 struct drm_dp_mst_topology_mgr *mgr,
2304 struct drm_dp_mst_branch *mstb, u8 port_number)
2306 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2311 kref_init(&port->topology_kref);
2312 kref_init(&port->malloc_kref);
2313 port->parent = mstb;
2314 port->port_num = port_number;
2316 port->aux.name = "DPMST";
2317 port->aux.dev = dev->dev;
2318 port->aux.is_remote = true;
2320 /* initialize the MST downstream port's AUX crc work queue */
2321 port->aux.drm_dev = dev;
2322 drm_dp_remote_aux_init(&port->aux);
2325 * Make sure the memory allocation for our parent branch stays
2326 * around until our own memory allocation is released
2328 drm_dp_mst_get_mstb_malloc(mstb);
2334 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2335 struct drm_device *dev,
2336 struct drm_dp_link_addr_reply_port *port_msg)
2338 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2339 struct drm_dp_mst_port *port;
2340 int old_ddps = 0, ret;
2341 u8 new_pdt = DP_PEER_DEVICE_NONE;
2343 bool created = false, send_link_addr = false, changed = false;
2345 port = drm_dp_get_port(mstb, port_msg->port_number);
2347 port = drm_dp_mst_add_port(dev, mgr, mstb,
2348 port_msg->port_number);
2353 } else if (!port->input && port_msg->input_port && port->connector) {
2354 /* Since port->connector can't be changed here, we create a
2355 * new port if input_port changes from 0 to 1
2357 drm_dp_mst_topology_unlink_port(mgr, port);
2358 drm_dp_mst_topology_put_port(port);
2359 port = drm_dp_mst_add_port(dev, mgr, mstb,
2360 port_msg->port_number);
2365 } else if (port->input && !port_msg->input_port) {
2367 } else if (port->connector) {
2368 /* We're updating a port that's exposed to userspace, so do it
2371 drm_modeset_lock(&mgr->base.lock, NULL);
2373 old_ddps = port->ddps;
2374 changed = port->ddps != port_msg->ddps ||
2376 (port->ldps != port_msg->legacy_device_plug_status ||
2377 port->dpcd_rev != port_msg->dpcd_revision ||
2378 port->mcs != port_msg->mcs ||
2379 port->pdt != port_msg->peer_device_type ||
2380 port->num_sdp_stream_sinks !=
2381 port_msg->num_sdp_stream_sinks));
2384 port->input = port_msg->input_port;
2386 new_pdt = port_msg->peer_device_type;
2387 new_mcs = port_msg->mcs;
2388 port->ddps = port_msg->ddps;
2389 port->ldps = port_msg->legacy_device_plug_status;
2390 port->dpcd_rev = port_msg->dpcd_revision;
2391 port->num_sdp_streams = port_msg->num_sdp_streams;
2392 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2394 /* manage mstb port lists with mgr lock - take a reference
2397 mutex_lock(&mgr->lock);
2398 drm_dp_mst_topology_get_port(port);
2399 list_add(&port->next, &mstb->ports);
2401 mutex_unlock(&mgr->lock);
2405 * Reprobe PBN caps on both hotplug, and when re-probing the link
2406 * for our parent mstb
2408 if (old_ddps != port->ddps || !created) {
2409 if (port->ddps && !port->input) {
2410 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2419 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2421 send_link_addr = true;
2422 } else if (ret < 0) {
2423 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret);
2428 * If this port wasn't just created, then we're reprobing because
2429 * we're coming out of suspend. In this case, always resend the link
2430 * address if there's an MSTB on this port
2432 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2434 send_link_addr = true;
2436 if (port->connector)
2437 drm_modeset_unlock(&mgr->base.lock);
2438 else if (!port->input)
2439 drm_dp_mst_port_add_connector(mstb, port);
2441 if (send_link_addr && port->mstb) {
2442 ret = drm_dp_send_link_address(mgr, port->mstb);
2443 if (ret == 1) /* MSTB below us changed */
2449 /* put reference to this port */
2450 drm_dp_mst_topology_put_port(port);
2454 drm_dp_mst_topology_unlink_port(mgr, port);
2455 if (port->connector)
2456 drm_modeset_unlock(&mgr->base.lock);
2458 drm_dp_mst_topology_put_port(port);
2463 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2464 struct drm_dp_connection_status_notify *conn_stat)
2466 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2467 struct drm_dp_mst_port *port;
2471 bool dowork = false, create_connector = false;
2473 port = drm_dp_get_port(mstb, conn_stat->port_number);
2477 if (port->connector) {
2478 if (!port->input && conn_stat->input_port) {
2480 * We can't remove a connector from an already exposed
2481 * port, so just throw the port out and make sure we
2482 * reprobe the link address of it's parent MSTB
2484 drm_dp_mst_topology_unlink_port(mgr, port);
2485 mstb->link_address_sent = false;
2490 /* Locking is only needed if the port's exposed to userspace */
2491 drm_modeset_lock(&mgr->base.lock, NULL);
2492 } else if (port->input && !conn_stat->input_port) {
2493 create_connector = true;
2494 /* Reprobe link address so we get num_sdp_streams */
2495 mstb->link_address_sent = false;
2499 old_ddps = port->ddps;
2500 port->input = conn_stat->input_port;
2501 port->ldps = conn_stat->legacy_device_plug_status;
2502 port->ddps = conn_stat->displayport_device_plug_status;
2504 if (old_ddps != port->ddps) {
2505 if (port->ddps && !port->input)
2506 drm_dp_send_enum_path_resources(mgr, mstb, port);
2511 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2512 new_mcs = conn_stat->message_capability_status;
2513 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2516 } else if (ret < 0) {
2517 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret);
2521 if (port->connector)
2522 drm_modeset_unlock(&mgr->base.lock);
2523 else if (create_connector)
2524 drm_dp_mst_port_add_connector(mstb, port);
2527 drm_dp_mst_topology_put_port(port);
2531 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2534 struct drm_dp_mst_branch *mstb;
2535 struct drm_dp_mst_port *port;
2537 /* find the port by iterating down */
2539 mutex_lock(&mgr->lock);
2540 mstb = mgr->mst_primary;
2545 for (i = 0; i < lct - 1; i++) {
2546 int shift = (i % 2) ? 0 : 4;
2547 int port_num = (rad[i / 2] >> shift) & 0xf;
2549 list_for_each_entry(port, &mstb->ports, next) {
2550 if (port->port_num == port_num) {
2554 "failed to lookup MSTB with lct %d, rad %02x\n",
2563 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2567 mutex_unlock(&mgr->lock);
2571 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2572 struct drm_dp_mst_branch *mstb,
2573 const uint8_t *guid)
2575 struct drm_dp_mst_branch *found_mstb;
2576 struct drm_dp_mst_port *port;
2581 if (memcmp(mstb->guid, guid, 16) == 0)
2585 list_for_each_entry(port, &mstb->ports, next) {
2586 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2595 static struct drm_dp_mst_branch *
2596 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2597 const uint8_t *guid)
2599 struct drm_dp_mst_branch *mstb;
2602 /* find the port by iterating down */
2603 mutex_lock(&mgr->lock);
2605 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2607 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2612 mutex_unlock(&mgr->lock);
2616 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2617 struct drm_dp_mst_branch *mstb)
2619 struct drm_dp_mst_port *port;
2621 bool changed = false;
2623 if (!mstb->link_address_sent) {
2624 ret = drm_dp_send_link_address(mgr, mstb);
2631 list_for_each_entry(port, &mstb->ports, next) {
2632 if (port->input || !port->ddps || !port->mstb)
2635 ret = drm_dp_check_and_send_link_address(mgr, port->mstb);
2645 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2647 struct drm_dp_mst_topology_mgr *mgr =
2648 container_of(work, struct drm_dp_mst_topology_mgr, work);
2649 struct drm_device *dev = mgr->dev;
2650 struct drm_dp_mst_branch *mstb;
2652 bool clear_payload_id_table;
2654 mutex_lock(&mgr->probe_lock);
2656 mutex_lock(&mgr->lock);
2657 clear_payload_id_table = !mgr->payload_id_table_cleared;
2658 mgr->payload_id_table_cleared = true;
2660 mstb = mgr->mst_primary;
2662 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2666 mutex_unlock(&mgr->lock);
2668 mutex_unlock(&mgr->probe_lock);
2673 * Certain branch devices seem to incorrectly report an available_pbn
2674 * of 0 on downstream sinks, even after clearing the
2675 * DP_PAYLOAD_ALLOCATE_* registers in
2676 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2677 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2678 * things work again.
2680 if (clear_payload_id_table) {
2681 drm_dbg_kms(dev, "Clearing payload ID table\n");
2682 drm_dp_send_clear_payload_id_table(mgr, mstb);
2685 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2686 drm_dp_mst_topology_put_mstb(mstb);
2688 mutex_unlock(&mgr->probe_lock);
2690 drm_kms_helper_hotplug_event(dev);
2693 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2698 if (memchr_inv(guid, 0, 16))
2701 salt = get_jiffies_64();
2703 memcpy(&guid[0], &salt, sizeof(u64));
2704 memcpy(&guid[8], &salt, sizeof(u64));
2709 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2710 u8 port_num, u32 offset, u8 num_bytes)
2712 struct drm_dp_sideband_msg_req_body req;
2714 req.req_type = DP_REMOTE_DPCD_READ;
2715 req.u.dpcd_read.port_number = port_num;
2716 req.u.dpcd_read.dpcd_address = offset;
2717 req.u.dpcd_read.num_bytes = num_bytes;
2718 drm_dp_encode_sideband_req(&req, msg);
2721 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2722 bool up, u8 *msg, int len)
2725 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2726 int tosend, total, offset;
2733 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2735 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2738 if (ret != tosend) {
2739 if (ret == -EIO && retries < 5) {
2743 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
2749 } while (total > 0);
2753 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2754 struct drm_dp_sideband_msg_tx *txmsg)
2756 struct drm_dp_mst_branch *mstb = txmsg->dst;
2759 req_type = txmsg->msg[0] & 0x7f;
2760 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2761 req_type == DP_RESOURCE_STATUS_NOTIFY ||
2762 req_type == DP_CLEAR_PAYLOAD_ID_TABLE)
2766 hdr->path_msg = txmsg->path_msg;
2767 if (hdr->broadcast) {
2771 hdr->lct = mstb->lct;
2772 hdr->lcr = mstb->lct - 1;
2775 memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
2780 * process a single block of the next message in the sideband queue
2782 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2783 struct drm_dp_sideband_msg_tx *txmsg,
2787 struct drm_dp_sideband_msg_hdr hdr;
2788 int len, space, idx, tosend;
2791 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2794 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2796 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2797 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2799 /* make hdr from dst mst */
2800 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2804 /* amount left to send in this message */
2805 len = txmsg->cur_len - txmsg->cur_offset;
2807 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2808 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2810 tosend = min(len, space);
2811 if (len == txmsg->cur_len)
2817 hdr.msg_len = tosend + 1;
2818 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2819 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2820 /* add crc at end */
2821 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2824 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2826 if (drm_debug_enabled(DRM_UT_DP)) {
2827 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2829 drm_printf(&p, "sideband msg failed to send\n");
2830 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2835 txmsg->cur_offset += tosend;
2836 if (txmsg->cur_offset == txmsg->cur_len) {
2837 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2843 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2845 struct drm_dp_sideband_msg_tx *txmsg;
2848 WARN_ON(!mutex_is_locked(&mgr->qlock));
2850 /* construct a chunk from the first msg in the tx_msg queue */
2851 if (list_empty(&mgr->tx_msg_downq))
2854 txmsg = list_first_entry(&mgr->tx_msg_downq,
2855 struct drm_dp_sideband_msg_tx, next);
2856 ret = process_single_tx_qlock(mgr, txmsg, false);
2858 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret);
2859 list_del(&txmsg->next);
2860 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2861 wake_up_all(&mgr->tx_waitq);
2865 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2866 struct drm_dp_sideband_msg_tx *txmsg)
2868 mutex_lock(&mgr->qlock);
2869 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2871 if (drm_debug_enabled(DRM_UT_DP)) {
2872 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2874 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2877 if (list_is_singular(&mgr->tx_msg_downq))
2878 process_single_down_tx_qlock(mgr);
2879 mutex_unlock(&mgr->qlock);
2883 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr,
2884 struct drm_dp_link_address_ack_reply *reply)
2886 struct drm_dp_link_addr_reply_port *port_reply;
2889 for (i = 0; i < reply->nports; i++) {
2890 port_reply = &reply->ports[i];
2891 drm_dbg_kms(mgr->dev,
2892 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2894 port_reply->input_port,
2895 port_reply->peer_device_type,
2896 port_reply->port_number,
2897 port_reply->dpcd_revision,
2900 port_reply->legacy_device_plug_status,
2901 port_reply->num_sdp_streams,
2902 port_reply->num_sdp_stream_sinks);
2906 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2907 struct drm_dp_mst_branch *mstb)
2909 struct drm_dp_sideband_msg_tx *txmsg;
2910 struct drm_dp_link_address_ack_reply *reply;
2911 struct drm_dp_mst_port *port, *tmp;
2912 int i, ret, port_mask = 0;
2913 bool changed = false;
2915 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2920 build_link_address(txmsg);
2922 mstb->link_address_sent = true;
2923 drm_dp_queue_down_tx(mgr, txmsg);
2925 /* FIXME: Actually do some real error handling here */
2926 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2928 drm_err(mgr->dev, "Sending link address failed with %d\n", ret);
2931 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2932 drm_err(mgr->dev, "link address NAK received\n");
2937 reply = &txmsg->reply.u.link_addr;
2938 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports);
2939 drm_dp_dump_link_address(mgr, reply);
2941 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2945 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2946 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret);
2950 for (i = 0; i < reply->nports; i++) {
2951 port_mask |= BIT(reply->ports[i].port_number);
2952 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2960 /* Prune any ports that are currently a part of mstb in our in-memory
2961 * topology, but were not seen in this link address. Usually this
2962 * means that they were removed while the topology was out of sync,
2963 * e.g. during suspend/resume
2965 mutex_lock(&mgr->lock);
2966 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2967 if (port_mask & BIT(port->port_num))
2970 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n",
2972 list_del(&port->next);
2973 drm_dp_mst_topology_put_port(port);
2976 mutex_unlock(&mgr->lock);
2980 mstb->link_address_sent = false;
2982 return ret < 0 ? ret : changed;
2986 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2987 struct drm_dp_mst_branch *mstb)
2989 struct drm_dp_sideband_msg_tx *txmsg;
2992 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2997 build_clear_payload_id_table(txmsg);
2999 drm_dp_queue_down_tx(mgr, txmsg);
3001 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3002 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3003 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n");
3009 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
3010 struct drm_dp_mst_branch *mstb,
3011 struct drm_dp_mst_port *port)
3013 struct drm_dp_enum_path_resources_ack_reply *path_res;
3014 struct drm_dp_sideband_msg_tx *txmsg;
3017 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3022 build_enum_path_resources(txmsg, port->port_num);
3024 drm_dp_queue_down_tx(mgr, txmsg);
3026 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3029 path_res = &txmsg->reply.u.path_resources;
3031 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3032 drm_dbg_kms(mgr->dev, "enum path resources nak received\n");
3034 if (port->port_num != path_res->port_number)
3035 DRM_ERROR("got incorrect port in response\n");
3037 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n",
3038 path_res->port_number,
3039 path_res->full_payload_bw_number,
3040 path_res->avail_payload_bw_number);
3043 * If something changed, make sure we send a
3046 if (port->full_pbn != path_res->full_payload_bw_number ||
3047 port->fec_capable != path_res->fec_capable)
3050 port->full_pbn = path_res->full_payload_bw_number;
3051 port->fec_capable = path_res->fec_capable;
3059 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3061 if (!mstb->port_parent)
3064 if (mstb->port_parent->mstb != mstb)
3065 return mstb->port_parent;
3067 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3071 * Searches upwards in the topology starting from mstb to try to find the
3072 * closest available parent of mstb that's still connected to the rest of the
3073 * topology. This can be used in order to perform operations like releasing
3074 * payloads, where the branch device which owned the payload may no longer be
3075 * around and thus would require that the payload on the last living relative
3078 static struct drm_dp_mst_branch *
3079 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3080 struct drm_dp_mst_branch *mstb,
3083 struct drm_dp_mst_branch *rmstb = NULL;
3084 struct drm_dp_mst_port *found_port;
3086 mutex_lock(&mgr->lock);
3087 if (!mgr->mst_primary)
3091 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3095 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3096 rmstb = found_port->parent;
3097 *port_num = found_port->port_num;
3099 /* Search again, starting from this parent */
3100 mstb = found_port->parent;
3104 mutex_unlock(&mgr->lock);
3108 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3109 struct drm_dp_mst_port *port,
3113 struct drm_dp_sideband_msg_tx *txmsg;
3114 struct drm_dp_mst_branch *mstb;
3116 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3119 port_num = port->port_num;
3120 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3122 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3130 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3136 for (i = 0; i < port->num_sdp_streams; i++)
3140 build_allocate_payload(txmsg, port_num,
3142 pbn, port->num_sdp_streams, sinks);
3144 drm_dp_queue_down_tx(mgr, txmsg);
3147 * FIXME: there is a small chance that between getting the last
3148 * connected mstb and sending the payload message, the last connected
3149 * mstb could also be removed from the topology. In the future, this
3150 * needs to be fixed by restarting the
3151 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3152 * timeout if the topology is still connected to the system.
3154 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3156 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3163 drm_dp_mst_topology_put_mstb(mstb);
3167 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3168 struct drm_dp_mst_port *port, bool power_up)
3170 struct drm_dp_sideband_msg_tx *txmsg;
3173 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3177 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3179 drm_dp_mst_topology_put_port(port);
3183 txmsg->dst = port->parent;
3184 build_power_updown_phy(txmsg, port->port_num, power_up);
3185 drm_dp_queue_down_tx(mgr, txmsg);
3187 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3189 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3195 drm_dp_mst_topology_put_port(port);
3199 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3201 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
3202 struct drm_dp_mst_port *port,
3203 struct drm_dp_query_stream_enc_status_ack_reply *status)
3205 struct drm_dp_mst_topology_state *state;
3206 struct drm_dp_mst_atomic_payload *payload;
3207 struct drm_dp_sideband_msg_tx *txmsg;
3211 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3215 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3221 get_random_bytes(nonce, sizeof(nonce));
3223 drm_modeset_lock(&mgr->base.lock, NULL);
3224 state = to_drm_dp_mst_topology_state(mgr->base.state);
3225 payload = drm_atomic_get_mst_payload_state(state, port);
3228 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
3229 * transaction at the MST Branch device directly connected to the
3232 txmsg->dst = mgr->mst_primary;
3234 build_query_stream_enc_status(txmsg, payload->vcpi, nonce);
3236 drm_dp_queue_down_tx(mgr, txmsg);
3238 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
3241 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3242 drm_dbg_kms(mgr->dev, "query encryption status nak received\n");
3248 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
3251 drm_modeset_unlock(&mgr->base.lock);
3252 drm_dp_mst_topology_put_port(port);
3257 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
3259 static int drm_dp_create_payload_at_dfp(struct drm_dp_mst_topology_mgr *mgr,
3260 struct drm_dp_mst_atomic_payload *payload)
3262 return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot,
3263 payload->time_slots);
3266 static int drm_dp_create_payload_to_remote(struct drm_dp_mst_topology_mgr *mgr,
3267 struct drm_dp_mst_atomic_payload *payload)
3270 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port);
3275 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn);
3276 drm_dp_mst_topology_put_port(port);
3280 static void drm_dp_destroy_payload_at_remote_and_dfp(struct drm_dp_mst_topology_mgr *mgr,
3281 struct drm_dp_mst_topology_state *mst_state,
3282 struct drm_dp_mst_atomic_payload *payload)
3284 drm_dbg_kms(mgr->dev, "\n");
3286 /* it's okay for these to fail */
3287 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE) {
3288 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0);
3289 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP;
3292 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_DFP)
3293 drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0);
3297 * drm_dp_add_payload_part1() - Execute payload update part 1
3298 * @mgr: Manager to use.
3299 * @mst_state: The MST atomic state
3300 * @payload: The payload to write
3302 * Determines the starting time slot for the given payload, and programs the VCPI for this payload
3303 * into the DPCD of DPRX. After calling this, the driver should generate ACT and payload packets.
3305 * Returns: 0 on success, error code on failure.
3307 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
3308 struct drm_dp_mst_topology_state *mst_state,
3309 struct drm_dp_mst_atomic_payload *payload)
3311 struct drm_dp_mst_port *port;
3314 /* Update mst mgr info */
3315 if (mgr->payload_count == 0)
3316 mgr->next_start_slot = mst_state->start_slot;
3318 payload->vc_start_slot = mgr->next_start_slot;
3320 mgr->payload_count++;
3321 mgr->next_start_slot += payload->time_slots;
3323 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL;
3325 /* Allocate payload to immediate downstream facing port */
3326 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port);
3328 drm_dbg_kms(mgr->dev,
3329 "VCPI %d for port %p not in topology, not creating a payload to remote\n",
3330 payload->vcpi, payload->port);
3334 ret = drm_dp_create_payload_at_dfp(mgr, payload);
3336 drm_dbg_kms(mgr->dev, "Failed to create MST payload for port %p: %d\n",
3337 payload->port, ret);
3341 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP;
3344 drm_dp_mst_topology_put_port(port);
3348 EXPORT_SYMBOL(drm_dp_add_payload_part1);
3351 * drm_dp_remove_payload_part1() - Remove an MST payload along the virtual channel
3352 * @mgr: Manager to use.
3353 * @mst_state: The MST atomic state
3354 * @payload: The payload to remove
3356 * Removes a payload along the virtual channel if it was successfully allocated.
3357 * After calling this, the driver should set HW to generate ACT and then switch to new
3358 * payload allocation state.
3360 void drm_dp_remove_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
3361 struct drm_dp_mst_topology_state *mst_state,
3362 struct drm_dp_mst_atomic_payload *payload)
3364 /* Remove remote payload allocation */
3365 bool send_remove = false;
3367 mutex_lock(&mgr->lock);
3368 send_remove = drm_dp_mst_port_downstream_of_branch(payload->port, mgr->mst_primary);
3369 mutex_unlock(&mgr->lock);
3372 drm_dp_destroy_payload_at_remote_and_dfp(mgr, mst_state, payload);
3374 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n",
3377 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL;
3379 EXPORT_SYMBOL(drm_dp_remove_payload_part1);
3382 * drm_dp_remove_payload_part2() - Remove an MST payload locally
3383 * @mgr: Manager to use.
3384 * @mst_state: The MST atomic state
3385 * @old_payload: The payload with its old state
3386 * @new_payload: The payload with its latest state
3388 * Updates the starting time slots of all other payloads which would have been shifted towards
3389 * the start of the payload ID table as a result of removing a payload. Driver should call this
3390 * function whenever it removes a payload in its HW. It's independent to the result of payload
3391 * allocation/deallocation at branch devices along the virtual channel.
3393 void drm_dp_remove_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
3394 struct drm_dp_mst_topology_state *mst_state,
3395 const struct drm_dp_mst_atomic_payload *old_payload,
3396 struct drm_dp_mst_atomic_payload *new_payload)
3398 struct drm_dp_mst_atomic_payload *pos;
3400 /* Remove local payload allocation */
3401 list_for_each_entry(pos, &mst_state->payloads, next) {
3402 if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot)
3403 pos->vc_start_slot -= old_payload->time_slots;
3405 new_payload->vc_start_slot = -1;
3407 mgr->payload_count--;
3408 mgr->next_start_slot -= old_payload->time_slots;
3410 if (new_payload->delete)
3411 drm_dp_mst_put_port_malloc(new_payload->port);
3413 new_payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE;
3415 EXPORT_SYMBOL(drm_dp_remove_payload_part2);
3417 * drm_dp_add_payload_part2() - Execute payload update part 2
3418 * @mgr: Manager to use.
3419 * @state: The global atomic state
3420 * @payload: The payload to update
3422 * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this
3423 * function will send the sideband messages to finish allocating this payload.
3425 * Returns: 0 on success, negative error code on failure.
3427 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
3428 struct drm_atomic_state *state,
3429 struct drm_dp_mst_atomic_payload *payload)
3433 /* Skip failed payloads */
3434 if (payload->payload_allocation_status != DRM_DP_MST_PAYLOAD_ALLOCATION_DFP) {
3435 drm_dbg_kms(state->dev, "Part 1 of payload creation for %s failed, skipping part 2\n",
3436 payload->port->connector->name);
3440 /* Allocate payload to remote end */
3441 ret = drm_dp_create_payload_to_remote(mgr, payload);
3443 drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n",
3444 payload->port, ret);
3446 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE;
3450 EXPORT_SYMBOL(drm_dp_add_payload_part2);
3452 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3453 struct drm_dp_mst_port *port,
3454 int offset, int size, u8 *bytes)
3457 struct drm_dp_sideband_msg_tx *txmsg;
3458 struct drm_dp_mst_branch *mstb;
3460 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3464 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3470 build_dpcd_read(txmsg, port->port_num, offset, size);
3471 txmsg->dst = port->parent;
3473 drm_dp_queue_down_tx(mgr, txmsg);
3475 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3479 if (txmsg->reply.reply_type == 1) {
3480 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3481 mstb, port->port_num, offset, size);
3486 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3491 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3493 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3498 drm_dp_mst_topology_put_mstb(mstb);
3503 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3504 struct drm_dp_mst_port *port,
3505 int offset, int size, u8 *bytes)
3508 struct drm_dp_sideband_msg_tx *txmsg;
3509 struct drm_dp_mst_branch *mstb;
3511 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3515 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3521 build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3524 drm_dp_queue_down_tx(mgr, txmsg);
3526 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3528 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3536 drm_dp_mst_topology_put_mstb(mstb);
3540 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3542 struct drm_dp_sideband_msg_reply_body reply;
3544 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3545 reply.req_type = req_type;
3546 drm_dp_encode_sideband_reply(&reply, msg);
3550 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3551 struct drm_dp_mst_branch *mstb,
3552 int req_type, bool broadcast)
3554 struct drm_dp_sideband_msg_tx *txmsg;
3556 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3561 drm_dp_encode_up_ack_reply(txmsg, req_type);
3563 mutex_lock(&mgr->qlock);
3564 /* construct a chunk from the first msg in the tx_msg queue */
3565 process_single_tx_qlock(mgr, txmsg, true);
3566 mutex_unlock(&mgr->qlock);
3573 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link
3574 * @mgr: The &drm_dp_mst_topology_mgr to use
3575 * @link_rate: link rate in 10kbits/s units
3576 * @link_lane_count: lane count
3578 * Calculate the total bandwidth of a MultiStream Transport link. The returned
3579 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to
3580 * convert the number of PBNs required for a given stream to the number of
3581 * timeslots this stream requires in each MTP.
3583 * Returns the BW / timeslot value in 20.12 fixed point format.
3585 fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
3586 int link_rate, int link_lane_count)
3588 int ch_coding_efficiency =
3589 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate));
3592 if (link_rate == 0 || link_lane_count == 0)
3593 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n",
3594 link_rate, link_lane_count);
3596 /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */
3597 ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count,
3598 ch_coding_efficiency),
3599 (1000000ULL * 8 * 5400) >> 12);
3603 EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
3606 * drm_dp_read_mst_cap() - check whether or not a sink supports MST
3607 * @aux: The DP AUX channel to use
3608 * @dpcd: A cached copy of the DPCD capabilities for this sink
3610 * Returns: %True if the sink supports MST, %false otherwise
3612 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
3613 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
3617 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
3620 if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
3623 return mstm_cap & DP_MST_CAP;
3625 EXPORT_SYMBOL(drm_dp_read_mst_cap);
3628 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3629 * @mgr: manager to set state for
3630 * @mst_state: true to enable MST on this connector - false to disable.
3632 * This is called by the driver when it detects an MST capable device plugged
3633 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3635 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3638 struct drm_dp_mst_branch *mstb = NULL;
3640 mutex_lock(&mgr->lock);
3641 if (mst_state == mgr->mst_state)
3644 mgr->mst_state = mst_state;
3645 /* set the device into MST mode */
3647 WARN_ON(mgr->mst_primary);
3650 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd);
3652 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n",
3653 mgr->aux->name, ret);
3657 /* add initial branch device at LCT 1 */
3658 mstb = drm_dp_add_mst_branch_device(1, NULL);
3665 /* give this the main reference */
3666 mgr->mst_primary = mstb;
3667 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3669 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3672 DP_UPSTREAM_IS_SRC);
3676 /* Write reset payload */
3677 drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f);
3679 queue_work(system_long_wq, &mgr->work);
3683 /* disable MST on the device */
3684 mstb = mgr->mst_primary;
3685 mgr->mst_primary = NULL;
3686 /* this can fail if the device is gone */
3687 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3689 mgr->payload_id_table_cleared = false;
3691 memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv));
3692 memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv));
3696 mutex_unlock(&mgr->lock);
3698 drm_dp_mst_topology_put_mstb(mstb);
3702 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3705 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3707 struct drm_dp_mst_port *port;
3709 /* The link address will need to be re-sent on resume */
3710 mstb->link_address_sent = false;
3712 list_for_each_entry(port, &mstb->ports, next)
3714 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3718 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3719 * @mgr: manager to suspend
3721 * This function tells the MST device that we can't handle UP messages
3722 * anymore. This should stop it from sending any since we are suspended.
3724 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3726 mutex_lock(&mgr->lock);
3727 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3728 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3729 mutex_unlock(&mgr->lock);
3730 flush_work(&mgr->up_req_work);
3731 flush_work(&mgr->work);
3732 flush_work(&mgr->delayed_destroy_work);
3734 mutex_lock(&mgr->lock);
3735 if (mgr->mst_state && mgr->mst_primary)
3736 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3737 mutex_unlock(&mgr->lock);
3739 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3742 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3743 * @mgr: manager to resume
3744 * @sync: whether or not to perform topology reprobing synchronously
3746 * This will fetch DPCD and see if the device is still there,
3747 * if it is, it will rewrite the MSTM control bits, and return.
3749 * If the device fails this returns -1, and the driver should do
3750 * a full MST reprobe, in case we were undocked.
3752 * During system resume (where it is assumed that the driver will be calling
3753 * drm_atomic_helper_resume()) this function should be called beforehand with
3754 * @sync set to true. In contexts like runtime resume where the driver is not
3755 * expected to be calling drm_atomic_helper_resume(), this function should be
3756 * called with @sync set to false in order to avoid deadlocking.
3758 * Returns: -1 if the MST topology was removed while we were suspended, 0
3761 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3767 mutex_lock(&mgr->lock);
3768 if (!mgr->mst_primary)
3771 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) {
3772 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3776 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3779 DP_UPSTREAM_IS_SRC);
3781 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
3785 /* Some hubs forget their guids after they resume */
3786 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3788 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3792 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3794 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n");
3799 * For the final step of resuming the topology, we need to bring the
3800 * state of our in-memory topology back into sync with reality. So,
3801 * restart the probing process as if we're probing a new hub
3803 queue_work(system_long_wq, &mgr->work);
3804 mutex_unlock(&mgr->lock);
3807 drm_dbg_kms(mgr->dev,
3808 "Waiting for link probe work to finish re-syncing topology...\n");
3809 flush_work(&mgr->work);
3815 mutex_unlock(&mgr->lock);
3818 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3821 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3822 struct drm_dp_mst_branch **mstb)
3826 int replylen, curreply;
3829 struct drm_dp_sideband_msg_hdr hdr;
3830 struct drm_dp_sideband_msg_rx *msg =
3831 up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3832 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3833 DP_SIDEBAND_MSG_DOWN_REP_BASE;
3838 len = min(mgr->max_dpcd_transaction_bytes, 16);
3839 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3841 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
3845 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen);
3847 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3848 1, replyblock, len, false);
3849 drm_dbg_kms(mgr->dev, "ERROR: failed header\n");
3854 /* Caller is responsible for giving back this reference */
3855 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3857 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct);
3862 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3863 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]);
3867 replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3868 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3870 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]);
3874 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3876 while (replylen > 0) {
3877 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3878 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3881 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
3886 ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3888 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n");
3898 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3900 struct drm_dp_sideband_msg_tx *txmsg;
3901 struct drm_dp_mst_branch *mstb = NULL;
3902 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3904 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3905 goto out_clear_reply;
3907 /* Multi-packet message transmission, don't clear the reply */
3908 if (!msg->have_eomt)
3911 /* find the message */
3912 mutex_lock(&mgr->qlock);
3913 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3914 struct drm_dp_sideband_msg_tx, next);
3915 mutex_unlock(&mgr->qlock);
3917 /* Were we actually expecting a response, and from this mstb? */
3918 if (!txmsg || txmsg->dst != mstb) {
3919 struct drm_dp_sideband_msg_hdr *hdr;
3921 hdr = &msg->initial_hdr;
3922 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
3923 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
3924 goto out_clear_reply;
3927 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply);
3929 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3930 drm_dbg_kms(mgr->dev,
3931 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3932 txmsg->reply.req_type,
3933 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3934 txmsg->reply.u.nak.reason,
3935 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3936 txmsg->reply.u.nak.nak_data);
3939 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3940 drm_dp_mst_topology_put_mstb(mstb);
3942 mutex_lock(&mgr->qlock);
3943 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3944 list_del(&txmsg->next);
3945 mutex_unlock(&mgr->qlock);
3947 wake_up_all(&mgr->tx_waitq);
3952 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3955 drm_dp_mst_topology_put_mstb(mstb);
3961 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3962 struct drm_dp_pending_up_req *up_req)
3964 struct drm_dp_mst_branch *mstb = NULL;
3965 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3966 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3967 bool hotplug = false, dowork = false;
3969 if (hdr->broadcast) {
3970 const u8 *guid = NULL;
3972 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3973 guid = msg->u.conn_stat.guid;
3974 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3975 guid = msg->u.resource_stat.guid;
3978 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3980 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3984 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct);
3988 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3989 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3990 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3994 drm_dp_mst_topology_put_mstb(mstb);
3997 queue_work(system_long_wq, &mgr->work);
4001 static void drm_dp_mst_up_req_work(struct work_struct *work)
4003 struct drm_dp_mst_topology_mgr *mgr =
4004 container_of(work, struct drm_dp_mst_topology_mgr,
4006 struct drm_dp_pending_up_req *up_req;
4007 bool send_hotplug = false;
4009 mutex_lock(&mgr->probe_lock);
4011 mutex_lock(&mgr->up_req_lock);
4012 up_req = list_first_entry_or_null(&mgr->up_req_list,
4013 struct drm_dp_pending_up_req,
4016 list_del(&up_req->next);
4017 mutex_unlock(&mgr->up_req_lock);
4022 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
4025 mutex_unlock(&mgr->probe_lock);
4028 drm_kms_helper_hotplug_event(mgr->dev);
4031 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
4033 struct drm_dp_pending_up_req *up_req;
4035 if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
4038 if (!mgr->up_req_recv.have_eomt)
4041 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
4045 INIT_LIST_HEAD(&up_req->next);
4047 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);
4049 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
4050 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
4051 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
4052 up_req->msg.req_type);
4057 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
4060 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
4061 const struct drm_dp_connection_status_notify *conn_stat =
4062 &up_req->msg.u.conn_stat;
4064 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
4065 conn_stat->port_number,
4066 conn_stat->legacy_device_plug_status,
4067 conn_stat->displayport_device_plug_status,
4068 conn_stat->message_capability_status,
4069 conn_stat->input_port,
4070 conn_stat->peer_device_type);
4071 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
4072 const struct drm_dp_resource_status_notify *res_stat =
4073 &up_req->msg.u.resource_stat;
4075 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
4076 res_stat->port_number,
4077 res_stat->available_pbn);
4080 up_req->hdr = mgr->up_req_recv.initial_hdr;
4081 mutex_lock(&mgr->up_req_lock);
4082 list_add_tail(&up_req->next, &mgr->up_req_list);
4083 mutex_unlock(&mgr->up_req_lock);
4084 queue_work(system_long_wq, &mgr->up_req_work);
4087 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
4092 * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event
4093 * @mgr: manager to notify irq for.
4094 * @esi: 4 bytes from SINK_COUNT_ESI
4095 * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI
4096 * @handled: whether the hpd interrupt was consumed or not
4098 * This should be called from the driver when it detects a HPD IRQ,
4099 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
4100 * topology manager will process the sideband messages received
4101 * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the
4102 * corresponding flags that Driver has to ack the DP receiver later.
4104 * Note that driver shall also call
4105 * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set
4106 * after calling this function, to try to kick off a new request in
4107 * the queue if the previous message transaction is completed.
4110 * drm_dp_mst_hpd_irq_send_new_request()
4112 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi,
4113 u8 *ack, bool *handled)
4118 sc = DP_GET_SINK_COUNT(esi[0]);
4120 if (sc != mgr->sink_count) {
4121 mgr->sink_count = sc;
4125 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
4126 ret = drm_dp_mst_handle_down_rep(mgr);
4128 ack[1] |= DP_DOWN_REP_MSG_RDY;
4131 if (esi[1] & DP_UP_REQ_MSG_RDY) {
4132 ret |= drm_dp_mst_handle_up_req(mgr);
4134 ack[1] |= DP_UP_REQ_MSG_RDY;
4139 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event);
4142 * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request
4143 * @mgr: manager to notify irq for.
4145 * This should be called from the driver when mst irq event is handled
4146 * and acked. Note that new down request should only be sent when
4147 * previous message transaction is completed. Source is not supposed to generate
4148 * interleaved message transactions.
4150 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr)
4152 struct drm_dp_sideband_msg_tx *txmsg;
4155 mutex_lock(&mgr->qlock);
4156 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
4157 struct drm_dp_sideband_msg_tx, next);
4158 /* If last transaction is not completed yet*/
4160 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
4161 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
4163 mutex_unlock(&mgr->qlock);
4166 drm_dp_mst_kick_tx(mgr);
4168 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request);
4170 * drm_dp_mst_detect_port() - get connection status for an MST port
4171 * @connector: DRM connector for this port
4172 * @ctx: The acquisition context to use for grabbing locks
4173 * @mgr: manager for this port
4174 * @port: pointer to a port
4176 * This returns the current connection state for a port.
4179 drm_dp_mst_detect_port(struct drm_connector *connector,
4180 struct drm_modeset_acquire_ctx *ctx,
4181 struct drm_dp_mst_topology_mgr *mgr,
4182 struct drm_dp_mst_port *port)
4186 /* we need to search for the port in the mgr in case it's gone */
4187 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4189 return connector_status_disconnected;
4191 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4195 ret = connector_status_disconnected;
4200 switch (port->pdt) {
4201 case DP_PEER_DEVICE_NONE:
4203 case DP_PEER_DEVICE_MST_BRANCHING:
4205 ret = connector_status_connected;
4208 case DP_PEER_DEVICE_SST_SINK:
4209 ret = connector_status_connected;
4210 /* for logical ports - cache the EDID */
4211 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
4212 port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
4214 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4216 ret = connector_status_connected;
4220 drm_dp_mst_topology_put_port(port);
4223 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4226 * drm_dp_mst_edid_read() - get EDID for an MST port
4227 * @connector: toplevel connector to get EDID for
4228 * @mgr: manager for this port
4229 * @port: unverified pointer to a port.
4231 * This returns an EDID for the port connected to a connector,
4232 * It validates the pointer still exists so the caller doesn't require a
4235 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
4236 struct drm_dp_mst_topology_mgr *mgr,
4237 struct drm_dp_mst_port *port)
4239 const struct drm_edid *drm_edid;
4241 /* we need to search for the port in the mgr in case it's gone */
4242 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4246 if (port->cached_edid)
4247 drm_edid = drm_edid_dup(port->cached_edid);
4249 drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
4251 drm_dp_mst_topology_put_port(port);
4255 EXPORT_SYMBOL(drm_dp_mst_edid_read);
4258 * drm_dp_mst_get_edid() - get EDID for an MST port
4259 * @connector: toplevel connector to get EDID for
4260 * @mgr: manager for this port
4261 * @port: unverified pointer to a port.
4263 * This function is deprecated; please use drm_dp_mst_edid_read() instead.
4265 * This returns an EDID for the port connected to a connector,
4266 * It validates the pointer still exists so the caller doesn't require a
4269 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
4270 struct drm_dp_mst_topology_mgr *mgr,
4271 struct drm_dp_mst_port *port)
4273 const struct drm_edid *drm_edid;
4276 drm_edid = drm_dp_mst_edid_read(connector, mgr, port);
4278 edid = drm_edid_duplicate(drm_edid_raw(drm_edid));
4280 drm_edid_free(drm_edid);
4284 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4287 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state
4288 * @state: global atomic state
4289 * @mgr: MST topology manager for the port
4290 * @port: port to find time slots for
4291 * @pbn: bandwidth required for the mode in PBN
4293 * Allocates time slots to @port, replacing any previous time slot allocations it may
4294 * have had. Any atomic drivers which support MST must call this function in
4295 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to
4296 * change the current time slot allocation for the new state, and ensure the MST
4297 * atomic state is added whenever the state of payloads in the topology changes.
4299 * Allocations set by this function are not checked against the bandwidth
4300 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4302 * Additionally, it is OK to call this function multiple times on the same
4303 * @port as needed. It is not OK however, to call this function and
4304 * drm_dp_atomic_release_time_slots() in the same atomic check phase.
4307 * drm_dp_atomic_release_time_slots()
4308 * drm_dp_mst_atomic_check()
4311 * Total slots in the atomic state assigned for this port, or a negative error
4312 * code if the port no longer exists
4314 int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state,
4315 struct drm_dp_mst_topology_mgr *mgr,
4316 struct drm_dp_mst_port *port, int pbn)
4318 struct drm_dp_mst_topology_state *topology_state;
4319 struct drm_dp_mst_atomic_payload *payload = NULL;
4320 struct drm_connector_state *conn_state;
4321 int prev_slots = 0, prev_bw = 0, req_slots;
4323 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4324 if (IS_ERR(topology_state))
4325 return PTR_ERR(topology_state);
4327 conn_state = drm_atomic_get_new_connector_state(state, port->connector);
4328 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc);
4330 /* Find the current allocation for this port, if any */
4331 payload = drm_atomic_get_mst_payload_state(topology_state, port);
4333 prev_slots = payload->time_slots;
4334 prev_bw = payload->pbn;
4337 * This should never happen, unless the driver tries
4338 * releasing and allocating the same timeslot allocation,
4341 if (drm_WARN_ON(mgr->dev, payload->delete)) {
4343 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n",
4349 req_slots = DIV_ROUND_UP(dfixed_const(pbn), topology_state->pbn_div.full);
4351 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n",
4352 port->connector->base.id, port->connector->name,
4353 port, prev_slots, req_slots);
4354 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4355 port->connector->base.id, port->connector->name,
4356 port, prev_bw, pbn);
4358 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */
4360 payload = kzalloc(sizeof(*payload), GFP_KERNEL);
4364 drm_dp_mst_get_port_malloc(port);
4365 payload->port = port;
4366 payload->vc_start_slot = -1;
4367 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE;
4368 list_add(&payload->next, &topology_state->payloads);
4370 payload->time_slots = req_slots;
4375 EXPORT_SYMBOL(drm_dp_atomic_find_time_slots);
4378 * drm_dp_atomic_release_time_slots() - Release allocated time slots
4379 * @state: global atomic state
4380 * @mgr: MST topology manager for the port
4381 * @port: The port to release the time slots from
4383 * Releases any time slots that have been allocated to a port in the atomic
4384 * state. Any atomic drivers which support MST must call this function
4385 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback.
4386 * This helper will check whether time slots would be released by the new state and
4387 * respond accordingly, along with ensuring the MST state is always added to the
4388 * atomic state whenever a new state would modify the state of payloads on the
4391 * It is OK to call this even if @port has been removed from the system.
4392 * Additionally, it is OK to call this function multiple times on the same
4393 * @port as needed. It is not OK however, to call this function and
4394 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check
4398 * drm_dp_atomic_find_time_slots()
4399 * drm_dp_mst_atomic_check()
4402 * 0 on success, negative error code otherwise
4404 int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state,
4405 struct drm_dp_mst_topology_mgr *mgr,
4406 struct drm_dp_mst_port *port)
4408 struct drm_dp_mst_topology_state *topology_state;
4409 struct drm_dp_mst_atomic_payload *payload;
4410 struct drm_connector_state *old_conn_state, *new_conn_state;
4411 bool update_payload = true;
4413 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector);
4414 if (!old_conn_state->crtc)
4417 /* If the CRTC isn't disabled by this state, don't release it's payload */
4418 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector);
4419 if (new_conn_state->crtc) {
4420 struct drm_crtc_state *crtc_state =
4421 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
4423 /* No modeset means no payload changes, so it's safe to not pull in the MST state */
4424 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state))
4427 if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
4428 update_payload = false;
4431 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4432 if (IS_ERR(topology_state))
4433 return PTR_ERR(topology_state);
4435 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc);
4436 if (!update_payload)
4439 payload = drm_atomic_get_mst_payload_state(topology_state, port);
4440 if (WARN_ON(!payload)) {
4441 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n",
4442 port, &topology_state->base);
4446 if (new_conn_state->crtc)
4449 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots);
4450 if (!payload->delete) {
4452 payload->delete = true;
4453 topology_state->payload_mask &= ~BIT(payload->vcpi - 1);
4458 EXPORT_SYMBOL(drm_dp_atomic_release_time_slots);
4461 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers
4462 * @state: global atomic state
4464 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs
4465 * currently assigned to an MST topology. Drivers must call this hook from their
4466 * &drm_mode_config_helper_funcs.atomic_commit_setup hook.
4469 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise
4471 int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state)
4473 struct drm_dp_mst_topology_mgr *mgr;
4474 struct drm_dp_mst_topology_state *mst_state;
4475 struct drm_crtc *crtc;
4476 struct drm_crtc_state *crtc_state;
4477 int i, j, commit_idx, num_commit_deps;
4479 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
4480 if (!mst_state->pending_crtc_mask)
4483 num_commit_deps = hweight32(mst_state->pending_crtc_mask);
4484 mst_state->commit_deps = kmalloc_array(num_commit_deps,
4485 sizeof(*mst_state->commit_deps), GFP_KERNEL);
4486 if (!mst_state->commit_deps)
4488 mst_state->num_commit_deps = num_commit_deps;
4491 for_each_new_crtc_in_state(state, crtc, crtc_state, j) {
4492 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) {
4493 mst_state->commit_deps[commit_idx++] =
4494 drm_crtc_commit_get(crtc_state->commit);
4501 EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit);
4504 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies,
4505 * prepare new MST state for commit
4506 * @state: global atomic state
4508 * Goes through any MST topologies in this atomic state, and waits for any pending commits which
4509 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before
4510 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing
4511 * with eachother by forcing them to be executed sequentially in situations where the only resources
4512 * the modeset objects in these commits share are an MST topology.
4514 * This function also prepares the new MST state for commit by performing some state preparation
4515 * which can't be done until this point, such as reading back the final VC start slots (which are
4516 * determined at commit-time) from the previous state.
4518 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(),
4519 * or whatever their equivalent of that is.
4521 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state)
4523 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state;
4524 struct drm_dp_mst_topology_mgr *mgr;
4525 struct drm_dp_mst_atomic_payload *old_payload, *new_payload;
4528 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) {
4529 for (j = 0; j < old_mst_state->num_commit_deps; j++) {
4530 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]);
4532 drm_err(state->dev, "Failed to wait for %s: %d\n",
4533 old_mst_state->commit_deps[j]->crtc->name, ret);
4536 /* Now that previous state is committed, it's safe to copy over the start slot
4537 * and allocation status assignments
4539 list_for_each_entry(old_payload, &old_mst_state->payloads, next) {
4540 if (old_payload->delete)
4543 new_payload = drm_atomic_get_mst_payload_state(new_mst_state,
4545 new_payload->vc_start_slot = old_payload->vc_start_slot;
4546 new_payload->payload_allocation_status =
4547 old_payload->payload_allocation_status;
4551 EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies);
4554 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating
4556 * @new_conn_state: The new connector state of the &drm_connector
4557 * @mgr: The MST topology manager for the &drm_connector
4559 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to
4560 * serialize non-blocking commits happening on the real DP connector of an MST topology switching
4561 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's
4562 * MST topology will never share the same &drm_encoder.
4564 * This function takes care of this serialization issue, by checking a root MST connector's atomic
4565 * state to determine if it is about to have a modeset - and then pulling in the MST topology state
4566 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask.
4568 * Drivers implementing MST must call this function from the
4569 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of
4570 * driving MST sinks.
4573 * 0 on success, negative error code otherwise
4575 int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state,
4576 struct drm_dp_mst_topology_mgr *mgr)
4578 struct drm_atomic_state *state = new_conn_state->state;
4579 struct drm_connector_state *old_conn_state =
4580 drm_atomic_get_old_connector_state(state, new_conn_state->connector);
4581 struct drm_crtc_state *crtc_state;
4582 struct drm_dp_mst_topology_state *mst_state = NULL;
4584 if (new_conn_state->crtc) {
4585 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
4586 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) {
4587 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
4588 if (IS_ERR(mst_state))
4589 return PTR_ERR(mst_state);
4591 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc);
4595 if (old_conn_state->crtc) {
4596 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc);
4597 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) {
4599 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
4600 if (IS_ERR(mst_state))
4601 return PTR_ERR(mst_state);
4604 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc);
4610 EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check);
4613 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
4614 * @mst_state: mst_state to update
4615 * @link_encoding_cap: the ecoding format on the link
4617 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
4619 if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
4620 mst_state->total_avail_slots = 64;
4621 mst_state->start_slot = 0;
4623 mst_state->total_avail_slots = 63;
4624 mst_state->start_slot = 1;
4627 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
4628 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
4631 EXPORT_SYMBOL(drm_dp_mst_update_slots);
4633 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4634 int id, u8 start_slot, u8 num_slots)
4636 u8 payload_alloc[3], status;
4640 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4641 DP_PAYLOAD_TABLE_UPDATED);
4643 payload_alloc[0] = id;
4644 payload_alloc[1] = start_slot;
4645 payload_alloc[2] = num_slots;
4647 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4649 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
4654 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4656 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
4660 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4663 usleep_range(10000, 20000);
4666 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
4676 static int do_get_act_status(struct drm_dp_aux *aux)
4681 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4689 * drm_dp_check_act_status() - Polls for ACT handled status.
4690 * @mgr: manager to use
4692 * Tries waiting for the MST hub to finish updating it's payload table by
4693 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4697 * 0 if the ACT was handled in time, negative error code on failure.
4699 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4702 * There doesn't seem to be any recommended retry count or timeout in
4703 * the MST specification. Since some hubs have been observed to take
4704 * over 1 second to update their payload allocations under certain
4705 * conditions, we use a rather large timeout value.
4707 const int timeout_ms = 3000;
4710 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4711 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4712 200, timeout_ms * USEC_PER_MSEC);
4713 if (ret < 0 && status >= 0) {
4714 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
4715 timeout_ms, status);
4717 } else if (status < 0) {
4719 * Failure here isn't unexpected - the hub may have
4720 * just been unplugged
4722 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
4728 EXPORT_SYMBOL(drm_dp_check_act_status);
4731 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4733 * @bpp: bpp as .4 binary fixed point
4735 * This uses the formula in the spec to calculate the PBN value for a mode.
4737 int drm_dp_calc_pbn_mode(int clock, int bpp)
4740 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4741 * common multiplier to render an integer PBN for all link rate/lane
4742 * counts combinations
4744 * peak_kbps = clock * bpp / 16
4745 * peak_kbps *= SSC overhead / 1000000
4746 * peak_kbps /= 8 convert to Kbytes
4747 * peak_kBps *= (64/54) / 1000 convert to PBN
4750 * TODO: Use the actual link and mode parameters to calculate
4751 * the overhead. For now it's assumed that these are
4752 * 4 link lanes, 4096 hactive pixels, which don't add any
4753 * significant data padding overhead and that there is no DSC
4756 int overhead = drm_dp_bw_overhead(4, 4096, 0, bpp,
4757 DRM_DP_BW_OVERHEAD_MST |
4758 DRM_DP_BW_OVERHEAD_SSC_REF_CLK);
4760 return DIV64_U64_ROUND_UP(mul_u32_u32(clock * bpp, 64 * overhead >> 4),
4761 1000000ULL * 8 * 54 * 1000);
4763 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4765 /* we want to kick the TX after we've ack the up/down IRQs. */
4766 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4768 queue_work(system_long_wq, &mgr->tx_work);
4772 * Helper function for parsing DP device types into convenient strings
4773 * for use with dp_mst_topology
4775 static const char *pdt_to_string(u8 pdt)
4778 case DP_PEER_DEVICE_NONE:
4780 case DP_PEER_DEVICE_SOURCE_OR_SST:
4781 return "SOURCE OR SST";
4782 case DP_PEER_DEVICE_MST_BRANCHING:
4783 return "MST BRANCHING";
4784 case DP_PEER_DEVICE_SST_SINK:
4786 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4787 return "DP LEGACY CONV";
4793 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4794 struct drm_dp_mst_branch *mstb)
4796 struct drm_dp_mst_port *port;
4797 int tabs = mstb->lct;
4801 for (i = 0; i < tabs; i++)
4805 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports);
4806 list_for_each_entry(port, &mstb->ports, next) {
4807 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n",
4811 port->input ? "input" : "output",
4812 pdt_to_string(port->pdt),
4815 port->num_sdp_streams,
4816 port->num_sdp_stream_sinks,
4817 port->fec_capable ? "true" : "false",
4820 drm_dp_mst_dump_mstb(m, port->mstb);
4824 #define DP_PAYLOAD_TABLE_SIZE 64
4826 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4831 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4832 if (drm_dp_dpcd_read(mgr->aux,
4833 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4840 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4841 struct drm_dp_mst_port *port, char *name,
4844 struct edid *mst_edid;
4846 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4847 drm_edid_get_monitor_name(mst_edid, name, namelen);
4852 * drm_dp_mst_dump_topology(): dump topology to seq file.
4853 * @m: seq_file to dump output to
4854 * @mgr: manager to dump current topology for.
4856 * helper to dump MST topology to a seq file for debugfs.
4858 void drm_dp_mst_dump_topology(struct seq_file *m,
4859 struct drm_dp_mst_topology_mgr *mgr)
4861 struct drm_dp_mst_topology_state *state;
4862 struct drm_dp_mst_atomic_payload *payload;
4865 static const char *const status[] = {
4872 mutex_lock(&mgr->lock);
4873 if (mgr->mst_primary)
4874 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4877 mutex_unlock(&mgr->lock);
4879 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock);
4883 state = to_drm_dp_mst_topology_state(mgr->base.state);
4884 seq_printf(m, "\n*** Atomic state info ***\n");
4885 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n",
4886 state->payload_mask, mgr->max_payloads, state->start_slot,
4887 dfixed_trunc(state->pbn_div));
4889 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | status | sink name |\n");
4890 for (i = 0; i < mgr->max_payloads; i++) {
4891 list_for_each_entry(payload, &state->payloads, next) {
4894 if (payload->vcpi != i || payload->delete)
4897 fetch_monitor_name(mgr, payload->port, name, sizeof(name));
4898 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %8s %19s\n",
4900 payload->port->port_num,
4902 payload->vc_start_slot,
4903 payload->vc_start_slot + payload->time_slots - 1,
4905 payload->dsc_enabled ? "Y" : "N",
4906 status[payload->payload_allocation_status],
4907 (*name != 0) ? name : "Unknown");
4911 seq_printf(m, "\n*** DPCD Info ***\n");
4912 mutex_lock(&mgr->lock);
4913 if (mgr->mst_primary) {
4914 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4917 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) {
4918 seq_printf(m, "dpcd read failed\n");
4921 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4923 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4925 seq_printf(m, "faux/mst read failed\n");
4928 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4930 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4932 seq_printf(m, "mst ctrl read failed\n");
4935 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4937 /* dump the standard OUI branch header */
4938 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4939 if (ret != DP_BRANCH_OUI_HEADER_SIZE) {
4940 seq_printf(m, "branch oui read failed\n");
4943 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4945 for (i = 0x3; i < 0x8 && buf[i]; i++)
4946 seq_printf(m, "%c", buf[i]);
4947 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4948 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4949 if (dump_dp_payload_table(mgr, buf))
4950 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4954 mutex_unlock(&mgr->lock);
4955 drm_modeset_unlock(&mgr->base.lock);
4957 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4959 static void drm_dp_tx_work(struct work_struct *work)
4961 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4963 mutex_lock(&mgr->qlock);
4964 if (!list_empty(&mgr->tx_msg_downq))
4965 process_single_down_tx_qlock(mgr);
4966 mutex_unlock(&mgr->qlock);
4970 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4972 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4974 if (port->connector) {
4975 drm_connector_unregister(port->connector);
4976 drm_connector_put(port->connector);
4979 drm_dp_mst_put_port_malloc(port);
4983 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4985 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4986 struct drm_dp_mst_port *port, *port_tmp;
4987 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4988 bool wake_tx = false;
4990 mutex_lock(&mgr->lock);
4991 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4992 list_del(&port->next);
4993 drm_dp_mst_topology_put_port(port);
4995 mutex_unlock(&mgr->lock);
4997 /* drop any tx slot msg */
4998 mutex_lock(&mstb->mgr->qlock);
4999 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
5000 if (txmsg->dst != mstb)
5003 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
5004 list_del(&txmsg->next);
5007 mutex_unlock(&mstb->mgr->qlock);
5010 wake_up_all(&mstb->mgr->tx_waitq);
5012 drm_dp_mst_put_mstb_malloc(mstb);
5015 static void drm_dp_delayed_destroy_work(struct work_struct *work)
5017 struct drm_dp_mst_topology_mgr *mgr =
5018 container_of(work, struct drm_dp_mst_topology_mgr,
5019 delayed_destroy_work);
5020 bool send_hotplug = false, go_again;
5023 * Not a regular list traverse as we have to drop the destroy
5024 * connector lock before destroying the mstb/port, to avoid AB->BA
5025 * ordering between this lock and the config mutex.
5031 struct drm_dp_mst_branch *mstb;
5033 mutex_lock(&mgr->delayed_destroy_lock);
5034 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
5035 struct drm_dp_mst_branch,
5038 list_del(&mstb->destroy_next);
5039 mutex_unlock(&mgr->delayed_destroy_lock);
5044 drm_dp_delayed_destroy_mstb(mstb);
5049 struct drm_dp_mst_port *port;
5051 mutex_lock(&mgr->delayed_destroy_lock);
5052 port = list_first_entry_or_null(&mgr->destroy_port_list,
5053 struct drm_dp_mst_port,
5056 list_del(&port->next);
5057 mutex_unlock(&mgr->delayed_destroy_lock);
5062 drm_dp_delayed_destroy_port(port);
5063 send_hotplug = true;
5069 drm_kms_helper_hotplug_event(mgr->dev);
5072 static struct drm_private_state *
5073 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
5075 struct drm_dp_mst_topology_state *state, *old_state =
5076 to_dp_mst_topology_state(obj->state);
5077 struct drm_dp_mst_atomic_payload *pos, *payload;
5079 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
5083 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
5085 INIT_LIST_HEAD(&state->payloads);
5086 state->commit_deps = NULL;
5087 state->num_commit_deps = 0;
5088 state->pending_crtc_mask = 0;
5090 list_for_each_entry(pos, &old_state->payloads, next) {
5091 /* Prune leftover freed timeslot allocations */
5095 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL);
5099 drm_dp_mst_get_port_malloc(payload->port);
5100 list_add(&payload->next, &state->payloads);
5103 return &state->base;
5106 list_for_each_entry_safe(pos, payload, &state->payloads, next) {
5107 drm_dp_mst_put_port_malloc(pos->port);
5115 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
5116 struct drm_private_state *state)
5118 struct drm_dp_mst_topology_state *mst_state =
5119 to_dp_mst_topology_state(state);
5120 struct drm_dp_mst_atomic_payload *pos, *tmp;
5123 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) {
5124 /* We only keep references to ports with active payloads */
5126 drm_dp_mst_put_port_malloc(pos->port);
5130 for (i = 0; i < mst_state->num_commit_deps; i++)
5131 drm_crtc_commit_put(mst_state->commit_deps[i]);
5133 kfree(mst_state->commit_deps);
5137 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
5138 struct drm_dp_mst_branch *branch)
5140 while (port->parent) {
5141 if (port->parent == branch)
5144 if (port->parent->port_parent)
5145 port = port->parent->port_parent;
5153 drm_dp_mst_port_downstream_of_parent_locked(struct drm_dp_mst_topology_mgr *mgr,
5154 struct drm_dp_mst_port *port,
5155 struct drm_dp_mst_port *parent)
5157 if (!mgr->mst_primary)
5160 port = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary,
5168 parent = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary,
5176 return drm_dp_mst_port_downstream_of_branch(port, parent->mstb);
5180 * drm_dp_mst_port_downstream_of_parent - check if a port is downstream of a parent port
5181 * @mgr: MST topology manager
5182 * @port: the port being looked up
5183 * @parent: the parent port
5185 * The function returns %true if @port is downstream of @parent. If @parent is
5186 * %NULL - denoting the root port - the function returns %true if @port is in
5190 drm_dp_mst_port_downstream_of_parent(struct drm_dp_mst_topology_mgr *mgr,
5191 struct drm_dp_mst_port *port,
5192 struct drm_dp_mst_port *parent)
5196 mutex_lock(&mgr->lock);
5197 ret = drm_dp_mst_port_downstream_of_parent_locked(mgr, port, parent);
5198 mutex_unlock(&mgr->lock);
5202 EXPORT_SYMBOL(drm_dp_mst_port_downstream_of_parent);
5205 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5206 struct drm_dp_mst_topology_state *state,
5207 struct drm_dp_mst_port **failing_port);
5210 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
5211 struct drm_dp_mst_topology_state *state,
5212 struct drm_dp_mst_port **failing_port)
5214 struct drm_dp_mst_atomic_payload *payload;
5215 struct drm_dp_mst_port *port;
5216 int pbn_used = 0, ret;
5219 /* Check that we have at least one port in our state that's downstream
5220 * of this branch, otherwise we can skip this branch
5222 list_for_each_entry(payload, &state->payloads, next) {
5223 if (!payload->pbn ||
5224 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb))
5233 if (mstb->port_parent)
5234 drm_dbg_atomic(mstb->mgr->dev,
5235 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
5236 mstb->port_parent->parent, mstb->port_parent, mstb);
5238 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb);
5240 list_for_each_entry(port, &mstb->ports, next) {
5241 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state, failing_port);
5252 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5253 struct drm_dp_mst_topology_state *state,
5254 struct drm_dp_mst_port **failing_port)
5256 struct drm_dp_mst_atomic_payload *payload;
5259 if (port->pdt == DP_PEER_DEVICE_NONE)
5262 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
5263 payload = drm_atomic_get_mst_payload_state(state, port);
5268 * This could happen if the sink deasserted its HPD line, but
5269 * the branch device still reports it as attached (PDT != NONE).
5271 if (!port->full_pbn) {
5272 drm_dbg_atomic(port->mgr->dev,
5273 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n",
5274 port->parent, port);
5275 *failing_port = port;
5279 pbn_used = payload->pbn;
5281 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
5288 if (pbn_used > port->full_pbn) {
5289 drm_dbg_atomic(port->mgr->dev,
5290 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
5291 port->parent, port, pbn_used, port->full_pbn);
5292 *failing_port = port;
5296 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
5297 port->parent, port, pbn_used, port->full_pbn);
5303 drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr,
5304 struct drm_dp_mst_topology_state *mst_state)
5306 struct drm_dp_mst_atomic_payload *payload;
5307 int avail_slots = mst_state->total_avail_slots, payload_count = 0;
5309 list_for_each_entry(payload, &mst_state->payloads, next) {
5310 /* Releasing payloads is always OK-even if the port is gone */
5311 if (payload->delete) {
5312 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n",
5317 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n",
5318 payload->port, payload->time_slots);
5320 avail_slots -= payload->time_slots;
5321 if (avail_slots < 0) {
5322 drm_dbg_atomic(mgr->dev,
5323 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n",
5324 payload->port, mst_state, avail_slots + payload->time_slots);
5328 if (++payload_count > mgr->max_payloads) {
5329 drm_dbg_atomic(mgr->dev,
5330 "[MST MGR:%p] state %p has too many payloads (max=%d)\n",
5331 mgr, mst_state, mgr->max_payloads);
5336 if (!payload->vcpi) {
5337 payload->vcpi = ffz(mst_state->payload_mask) + 1;
5338 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n",
5339 payload->port, payload->vcpi);
5340 mst_state->payload_mask |= BIT(payload->vcpi - 1);
5345 mst_state->pbn_div.full = dfixed_const(0);
5347 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n",
5348 mgr, mst_state, dfixed_trunc(mst_state->pbn_div), avail_slots,
5349 mst_state->total_avail_slots - avail_slots);
5355 * drm_dp_mst_add_affected_dsc_crtcs
5356 * @state: Pointer to the new struct drm_dp_mst_topology_state
5357 * @mgr: MST topology manager
5359 * Whenever there is a change in mst topology
5360 * DSC configuration would have to be recalculated
5361 * therefore we need to trigger modeset on all affected
5362 * CRTCs in that topology
5365 * drm_dp_mst_atomic_enable_dsc()
5367 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5369 struct drm_dp_mst_topology_state *mst_state;
5370 struct drm_dp_mst_atomic_payload *pos;
5371 struct drm_connector *connector;
5372 struct drm_connector_state *conn_state;
5373 struct drm_crtc *crtc;
5374 struct drm_crtc_state *crtc_state;
5376 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5378 if (IS_ERR(mst_state))
5379 return PTR_ERR(mst_state);
5381 list_for_each_entry(pos, &mst_state->payloads, next) {
5383 connector = pos->port->connector;
5388 conn_state = drm_atomic_get_connector_state(state, connector);
5390 if (IS_ERR(conn_state))
5391 return PTR_ERR(conn_state);
5393 crtc = conn_state->crtc;
5398 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5401 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5403 if (IS_ERR(crtc_state))
5404 return PTR_ERR(crtc_state);
5406 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5409 crtc_state->mode_changed = true;
5413 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5416 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5417 * @state: Pointer to the new drm_atomic_state
5418 * @port: Pointer to the affected MST Port
5419 * @pbn: Newly recalculated bw required for link with DSC enabled
5420 * @enable: Boolean flag to enable or disable DSC on the port
5422 * This function enables DSC on the given Port
5423 * by recalculating its vcpi from pbn provided
5424 * and sets dsc_enable flag to keep track of which
5425 * ports have DSC enabled
5428 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5429 struct drm_dp_mst_port *port,
5430 int pbn, bool enable)
5432 struct drm_dp_mst_topology_state *mst_state;
5433 struct drm_dp_mst_atomic_payload *payload;
5436 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5437 if (IS_ERR(mst_state))
5438 return PTR_ERR(mst_state);
5440 payload = drm_atomic_get_mst_payload_state(mst_state, port);
5442 drm_dbg_atomic(state->dev,
5443 "[MST PORT:%p] Couldn't find payload in mst state %p\n",
5448 if (payload->dsc_enabled == enable) {
5449 drm_dbg_atomic(state->dev,
5450 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n",
5451 port, enable, payload->time_slots);
5452 time_slots = payload->time_slots;
5456 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn);
5457 drm_dbg_atomic(state->dev,
5458 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n",
5464 payload->dsc_enabled = enable;
5468 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5471 * drm_dp_mst_atomic_check_mgr - Check the atomic state of an MST topology manager
5472 * @state: The global atomic state
5473 * @mgr: Manager to check
5474 * @mst_state: The MST atomic state for @mgr
5475 * @failing_port: Returns the port with a BW limitation
5477 * Checks the given MST manager's topology state for an atomic update to ensure
5478 * that it's valid. This includes checking whether there's enough bandwidth to
5479 * support the new timeslot allocations in the atomic update.
5481 * Any atomic drivers supporting DP MST must make sure to call this or
5482 * the drm_dp_mst_atomic_check() function after checking the rest of their state
5483 * in their &drm_mode_config_funcs.atomic_check() callback.
5486 * drm_dp_mst_atomic_check()
5487 * drm_dp_atomic_find_time_slots()
5488 * drm_dp_atomic_release_time_slots()
5491 * - 0 if the new state is valid
5492 * - %-ENOSPC, if the new state is invalid, because of BW limitation
5493 * @failing_port is set to:
5494 * - The non-root port where a BW limit check failed
5495 * with all the ports downstream of @failing_port passing
5496 * the BW limit check.
5497 * The returned port pointer is valid until at least
5498 * one payload downstream of it exists.
5499 * - %NULL if the BW limit check failed at the root port
5500 * with all the ports downstream of the root port passing
5501 * the BW limit check.
5502 * - %-EINVAL, if the new state is invalid, because the root port has
5503 * too many payloads.
5505 int drm_dp_mst_atomic_check_mgr(struct drm_atomic_state *state,
5506 struct drm_dp_mst_topology_mgr *mgr,
5507 struct drm_dp_mst_topology_state *mst_state,
5508 struct drm_dp_mst_port **failing_port)
5512 *failing_port = NULL;
5514 if (!mgr->mst_state)
5517 mutex_lock(&mgr->lock);
5518 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5521 mutex_unlock(&mgr->lock);
5526 return drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state);
5528 EXPORT_SYMBOL(drm_dp_mst_atomic_check_mgr);
5531 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5532 * atomic update is valid
5533 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5535 * Checks the given topology state for an atomic update to ensure that it's
5536 * valid, calling drm_dp_mst_atomic_check_mgr() for all MST manager in the
5537 * atomic state. This includes checking whether there's enough bandwidth to
5538 * support the new timeslot allocations in the atomic update.
5540 * Any atomic drivers supporting DP MST must make sure to call this after
5541 * checking the rest of their state in their
5542 * &drm_mode_config_funcs.atomic_check() callback.
5545 * drm_dp_mst_atomic_check_mgr()
5546 * drm_dp_atomic_find_time_slots()
5547 * drm_dp_atomic_release_time_slots()
5551 * 0 if the new state is valid, negative error code otherwise.
5553 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5555 struct drm_dp_mst_topology_mgr *mgr;
5556 struct drm_dp_mst_topology_state *mst_state;
5559 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5560 struct drm_dp_mst_port *tmp_port;
5562 ret = drm_dp_mst_atomic_check_mgr(state, mgr, mst_state, &tmp_port);
5569 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5571 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5572 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5573 .atomic_destroy_state = drm_dp_mst_destroy_state,
5575 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5578 * drm_atomic_get_mst_topology_state: get MST topology state
5579 * @state: global atomic state
5580 * @mgr: MST topology manager, also the private object in this case
5582 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5583 * state vtable so that the private object state returned is that of a MST
5588 * The MST topology state or error pointer.
5590 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5591 struct drm_dp_mst_topology_mgr *mgr)
5593 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5595 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5598 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any
5599 * @state: global atomic state
5600 * @mgr: MST topology manager, also the private object in this case
5602 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic
5603 * state vtable so that the private object state returned is that of a MST
5608 * The old MST topology state, or NULL if there's no topology state for this MST mgr
5609 * in the global atomic state
5611 struct drm_dp_mst_topology_state *
5612 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
5613 struct drm_dp_mst_topology_mgr *mgr)
5615 struct drm_private_state *old_priv_state =
5616 drm_atomic_get_old_private_obj_state(state, &mgr->base);
5618 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL;
5620 EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state);
5623 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any
5624 * @state: global atomic state
5625 * @mgr: MST topology manager, also the private object in this case
5627 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic
5628 * state vtable so that the private object state returned is that of a MST
5633 * The new MST topology state, or NULL if there's no topology state for this MST mgr
5634 * in the global atomic state
5636 struct drm_dp_mst_topology_state *
5637 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
5638 struct drm_dp_mst_topology_mgr *mgr)
5640 struct drm_private_state *new_priv_state =
5641 drm_atomic_get_new_private_obj_state(state, &mgr->base);
5643 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL;
5645 EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state);
5648 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5649 * @mgr: manager struct to initialise
5650 * @dev: device providing this structure - for i2c addition.
5651 * @aux: DP helper aux channel to talk to this device
5652 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5653 * @max_payloads: maximum number of payloads this GPU can source
5654 * @conn_base_id: the connector object ID the MST device is connected to.
5656 * Return 0 for success, or negative error code on failure
5658 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5659 struct drm_device *dev, struct drm_dp_aux *aux,
5660 int max_dpcd_transaction_bytes, int max_payloads,
5663 struct drm_dp_mst_topology_state *mst_state;
5665 mutex_init(&mgr->lock);
5666 mutex_init(&mgr->qlock);
5667 mutex_init(&mgr->delayed_destroy_lock);
5668 mutex_init(&mgr->up_req_lock);
5669 mutex_init(&mgr->probe_lock);
5670 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5671 mutex_init(&mgr->topology_ref_history_lock);
5674 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5675 INIT_LIST_HEAD(&mgr->destroy_port_list);
5676 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5677 INIT_LIST_HEAD(&mgr->up_req_list);
5680 * delayed_destroy_work will be queued on a dedicated WQ, so that any
5681 * requeuing will be also flushed when deiniting the topology manager.
5683 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5684 if (mgr->delayed_destroy_wq == NULL)
5687 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5688 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5689 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5690 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5691 init_waitqueue_head(&mgr->tx_waitq);
5694 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5695 mgr->max_payloads = max_payloads;
5696 mgr->conn_base_id = conn_base_id;
5698 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5699 if (mst_state == NULL)
5702 mst_state->total_avail_slots = 63;
5703 mst_state->start_slot = 1;
5705 mst_state->mgr = mgr;
5706 INIT_LIST_HEAD(&mst_state->payloads);
5708 drm_atomic_private_obj_init(dev, &mgr->base,
5710 &drm_dp_mst_topology_state_funcs);
5714 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5717 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5718 * @mgr: manager to destroy
5720 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5722 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5723 flush_work(&mgr->work);
5724 /* The following will also drain any requeued work on the WQ. */
5725 if (mgr->delayed_destroy_wq) {
5726 destroy_workqueue(mgr->delayed_destroy_wq);
5727 mgr->delayed_destroy_wq = NULL;
5731 drm_atomic_private_obj_fini(&mgr->base);
5734 mutex_destroy(&mgr->delayed_destroy_lock);
5735 mutex_destroy(&mgr->qlock);
5736 mutex_destroy(&mgr->lock);
5737 mutex_destroy(&mgr->up_req_lock);
5738 mutex_destroy(&mgr->probe_lock);
5739 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5740 mutex_destroy(&mgr->topology_ref_history_lock);
5743 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5745 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5749 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5752 for (i = 0; i < num - 1; i++) {
5753 if (msgs[i].flags & I2C_M_RD ||
5758 return msgs[num - 1].flags & I2C_M_RD &&
5759 msgs[num - 1].len <= 0xff;
5762 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num)
5766 for (i = 0; i < num - 1; i++) {
5767 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) ||
5772 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff;
5775 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb,
5776 struct drm_dp_mst_port *port,
5777 struct i2c_msg *msgs, int num)
5779 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5781 struct drm_dp_sideband_msg_req_body msg;
5782 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5785 memset(&msg, 0, sizeof(msg));
5786 msg.req_type = DP_REMOTE_I2C_READ;
5787 msg.u.i2c_read.num_transactions = num - 1;
5788 msg.u.i2c_read.port_number = port->port_num;
5789 for (i = 0; i < num - 1; i++) {
5790 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5791 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5792 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5793 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5795 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5796 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5798 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5805 drm_dp_encode_sideband_req(&msg, txmsg);
5807 drm_dp_queue_down_tx(mgr, txmsg);
5809 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5812 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5816 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5820 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5828 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb,
5829 struct drm_dp_mst_port *port,
5830 struct i2c_msg *msgs, int num)
5832 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5834 struct drm_dp_sideband_msg_req_body msg;
5835 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5838 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5843 for (i = 0; i < num; i++) {
5844 memset(&msg, 0, sizeof(msg));
5845 msg.req_type = DP_REMOTE_I2C_WRITE;
5846 msg.u.i2c_write.port_number = port->port_num;
5847 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr;
5848 msg.u.i2c_write.num_bytes = msgs[i].len;
5849 msg.u.i2c_write.bytes = msgs[i].buf;
5851 memset(txmsg, 0, sizeof(*txmsg));
5854 drm_dp_encode_sideband_req(&msg, txmsg);
5855 drm_dp_queue_down_tx(mgr, txmsg);
5857 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5859 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5874 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter,
5875 struct i2c_msg *msgs, int num)
5877 struct drm_dp_aux *aux = adapter->algo_data;
5878 struct drm_dp_mst_port *port =
5879 container_of(aux, struct drm_dp_mst_port, aux);
5880 struct drm_dp_mst_branch *mstb;
5881 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5884 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5888 if (remote_i2c_read_ok(msgs, num)) {
5889 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num);
5890 } else if (remote_i2c_write_ok(msgs, num)) {
5891 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num);
5893 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n");
5897 drm_dp_mst_topology_put_mstb(mstb);
5901 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5903 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5904 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5905 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5906 I2C_FUNC_10BIT_ADDR;
5909 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5910 .functionality = drm_dp_mst_i2c_functionality,
5911 .master_xfer = drm_dp_mst_i2c_xfer,
5915 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5916 * @port: The port to add the I2C bus on
5918 * Returns 0 on success or a negative error code on failure.
5920 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5922 struct drm_dp_aux *aux = &port->aux;
5923 struct device *parent_dev = port->mgr->dev->dev;
5925 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5926 aux->ddc.algo_data = aux;
5927 aux->ddc.retries = 3;
5929 aux->ddc.owner = THIS_MODULE;
5930 /* FIXME: set the kdev of the port's connector as parent */
5931 aux->ddc.dev.parent = parent_dev;
5932 aux->ddc.dev.of_node = parent_dev->of_node;
5934 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5935 sizeof(aux->ddc.name));
5937 return i2c_add_adapter(&aux->ddc);
5941 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5942 * @port: The port to remove the I2C bus from
5944 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5946 i2c_del_adapter(&port->aux.ddc);
5950 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5951 * @port: The port to check
5953 * A single physical MST hub object can be represented in the topology
5954 * by multiple branches, with virtual ports between those branches.
5956 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5957 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5958 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5960 * May acquire mgr->lock
5963 * true if the port is a virtual DP peer device, false otherwise
5965 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5967 struct drm_dp_mst_port *downstream_port;
5969 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5972 /* Virtual DP Sink (Internal Display Panel) */
5973 if (port->port_num >= 8)
5976 /* DP-to-HDMI Protocol Converter */
5977 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5983 mutex_lock(&port->mgr->lock);
5984 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5986 port->mstb->num_ports == 2) {
5987 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5988 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5989 !downstream_port->input) {
5990 mutex_unlock(&port->mgr->lock);
5995 mutex_unlock(&port->mgr->lock);
6001 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
6002 * @port: The port to check. A leaf of the MST tree with an attached display.
6004 * Depending on the situation, DSC may be enabled via the endpoint aux,
6005 * the immediately upstream aux, or the connector's physical aux.
6007 * This is both the correct aux to read DSC_CAPABILITY and the
6008 * correct aux to write DSC_ENABLED.
6010 * This operation can be expensive (up to four aux reads), so
6011 * the caller should cache the return.
6014 * NULL if DSC cannot be enabled on this port, otherwise the aux device
6016 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
6018 struct drm_dp_mst_port *immediate_upstream_port;
6019 struct drm_dp_aux *immediate_upstream_aux;
6020 struct drm_dp_mst_port *fec_port;
6021 struct drm_dp_desc desc = {};
6028 if (port->parent->port_parent)
6029 immediate_upstream_port = port->parent->port_parent;
6031 immediate_upstream_port = NULL;
6033 fec_port = immediate_upstream_port;
6036 * Each physical link (i.e. not a virtual port) between the
6037 * output and the primary device must support FEC
6039 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
6040 !fec_port->fec_capable)
6043 fec_port = fec_port->parent->port_parent;
6046 /* DP-to-DP peer device */
6047 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
6050 if (drm_dp_dpcd_read(&port->aux,
6051 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
6053 if (drm_dp_dpcd_read(&port->aux,
6054 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
6056 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
6057 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
6060 /* Enpoint decompression with DP-to-DP peer device */
6061 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
6062 (endpoint_fec & DP_FEC_CAPABLE) &&
6063 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) {
6064 port->passthrough_aux = &immediate_upstream_port->aux;
6068 /* Virtual DPCD decompression with DP-to-DP peer device */
6069 return &immediate_upstream_port->aux;
6072 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
6073 if (drm_dp_mst_is_virtual_dpcd(port))
6078 * Applies to ports for which:
6079 * - Physical aux has Synaptics OUI
6080 * - DPv1.4 or higher
6081 * - Port is on primary branch device
6082 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
6084 if (immediate_upstream_port)
6085 immediate_upstream_aux = &immediate_upstream_port->aux;
6087 immediate_upstream_aux = port->mgr->aux;
6089 if (drm_dp_read_desc(immediate_upstream_aux, &desc, true))
6092 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) {
6093 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
6095 if (drm_dp_read_dpcd_caps(immediate_upstream_aux, dpcd_ext) < 0)
6098 if (dpcd_ext[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
6099 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) &&
6100 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK)
6101 != DP_DWN_STRM_PORT_TYPE_ANALOG)))
6102 return immediate_upstream_aux;
6106 * The check below verifies if the MST sink
6107 * connected to the GPU is capable of DSC -
6108 * therefore the endpoint needs to be
6109 * both DSC and FEC capable.
6111 if (drm_dp_dpcd_read(&port->aux,
6112 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
6114 if (drm_dp_dpcd_read(&port->aux,
6115 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
6117 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
6118 (endpoint_fec & DP_FEC_CAPABLE))
6123 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);