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/delay.h>
24 #include <linux/errno.h>
25 #include <linux/i2c.h>
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/seq_file.h>
31 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
32 #include <linux/stacktrace.h>
33 #include <linux/sort.h>
34 #include <linux/timekeeping.h>
35 #include <linux/math64.h>
38 #include <drm/drm_atomic.h>
39 #include <drm/drm_atomic_helper.h>
40 #include <drm/drm_dp_mst_helper.h>
41 #include <drm/drm_drv.h>
42 #include <drm/drm_print.h>
43 #include <drm/drm_probe_helper.h>
45 #include "drm_crtc_helper_internal.h"
46 #include "drm_dp_mst_topology_internal.h"
51 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
52 * protocol. The helpers contain a topology manager and bandwidth manager.
53 * The helpers encapsulate the sending and received of sideband msgs.
55 struct drm_dp_pending_up_req {
56 struct drm_dp_sideband_msg_hdr hdr;
57 struct drm_dp_sideband_msg_req_body msg;
58 struct list_head next;
61 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
64 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
66 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
68 struct drm_dp_payload *payload);
70 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
71 struct drm_dp_mst_port *port,
72 int offset, int size, u8 *bytes);
73 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
74 struct drm_dp_mst_port *port,
75 int offset, int size, u8 *bytes);
77 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
78 struct drm_dp_mst_branch *mstb);
81 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
82 struct drm_dp_mst_branch *mstb);
84 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
85 struct drm_dp_mst_branch *mstb,
86 struct drm_dp_mst_port *port);
87 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
90 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
91 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
92 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
94 #define DBG_PREFIX "[dp_mst]"
96 #define DP_STR(x) [DP_ ## x] = #x
98 static const char *drm_dp_mst_req_type_str(u8 req_type)
100 static const char * const req_type_str[] = {
101 DP_STR(GET_MSG_TRANSACTION_VERSION),
102 DP_STR(LINK_ADDRESS),
103 DP_STR(CONNECTION_STATUS_NOTIFY),
104 DP_STR(ENUM_PATH_RESOURCES),
105 DP_STR(ALLOCATE_PAYLOAD),
106 DP_STR(QUERY_PAYLOAD),
107 DP_STR(RESOURCE_STATUS_NOTIFY),
108 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
109 DP_STR(REMOTE_DPCD_READ),
110 DP_STR(REMOTE_DPCD_WRITE),
111 DP_STR(REMOTE_I2C_READ),
112 DP_STR(REMOTE_I2C_WRITE),
113 DP_STR(POWER_UP_PHY),
114 DP_STR(POWER_DOWN_PHY),
115 DP_STR(SINK_EVENT_NOTIFY),
116 DP_STR(QUERY_STREAM_ENC_STATUS),
119 if (req_type >= ARRAY_SIZE(req_type_str) ||
120 !req_type_str[req_type])
123 return req_type_str[req_type];
127 #define DP_STR(x) [DP_NAK_ ## x] = #x
129 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
131 static const char * const nak_reason_str[] = {
132 DP_STR(WRITE_FAILURE),
133 DP_STR(INVALID_READ),
137 DP_STR(LINK_FAILURE),
138 DP_STR(NO_RESOURCES),
141 DP_STR(ALLOCATE_FAIL),
144 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
145 !nak_reason_str[nak_reason])
148 return nak_reason_str[nak_reason];
152 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
154 static const char *drm_dp_mst_sideband_tx_state_str(int state)
156 static const char * const sideband_reason_str[] = {
164 if (state >= ARRAY_SIZE(sideband_reason_str) ||
165 !sideband_reason_str[state])
168 return sideband_reason_str[state];
172 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
177 for (i = 0; i < lct; i++) {
179 unpacked_rad[i] = rad[i / 2] >> 4;
181 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
184 /* TODO: Eventually add something to printk so we can format the rad
187 return snprintf(out, len, "%*phC", lct, unpacked_rad);
190 /* sideband msg handling */
191 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
196 int number_of_bits = num_nibbles * 4;
199 while (number_of_bits != 0) {
202 remainder |= (data[array_index] & bitmask) >> bitshift;
210 if ((remainder & 0x10) == 0x10)
215 while (number_of_bits != 0) {
218 if ((remainder & 0x10) != 0)
225 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
230 int number_of_bits = number_of_bytes * 8;
233 while (number_of_bits != 0) {
236 remainder |= (data[array_index] & bitmask) >> bitshift;
244 if ((remainder & 0x100) == 0x100)
249 while (number_of_bits != 0) {
252 if ((remainder & 0x100) != 0)
256 return remainder & 0xff;
258 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
261 size += (hdr->lct / 2);
265 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
271 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
272 for (i = 0; i < (hdr->lct / 2); i++)
273 buf[idx++] = hdr->rad[i];
274 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
275 (hdr->msg_len & 0x3f);
276 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
278 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
279 buf[idx - 1] |= (crc4 & 0xf);
284 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
285 u8 *buf, int buflen, u8 *hdrlen)
294 len += ((buf[0] & 0xf0) >> 4) / 2;
297 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
299 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
300 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
304 hdr->lct = (buf[0] & 0xf0) >> 4;
305 hdr->lcr = (buf[0] & 0xf);
307 for (i = 0; i < (hdr->lct / 2); i++)
308 hdr->rad[i] = buf[idx++];
309 hdr->broadcast = (buf[idx] >> 7) & 0x1;
310 hdr->path_msg = (buf[idx] >> 6) & 0x1;
311 hdr->msg_len = buf[idx] & 0x3f;
313 hdr->somt = (buf[idx] >> 7) & 0x1;
314 hdr->eomt = (buf[idx] >> 6) & 0x1;
315 hdr->seqno = (buf[idx] >> 4) & 0x1;
322 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
323 struct drm_dp_sideband_msg_tx *raw)
328 buf[idx++] = req->req_type & 0x7f;
330 switch (req->req_type) {
331 case DP_ENUM_PATH_RESOURCES:
332 case DP_POWER_DOWN_PHY:
333 case DP_POWER_UP_PHY:
334 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
337 case DP_ALLOCATE_PAYLOAD:
338 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
339 (req->u.allocate_payload.number_sdp_streams & 0xf);
341 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
343 buf[idx] = (req->u.allocate_payload.pbn >> 8);
345 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
347 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
348 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
349 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
352 if (req->u.allocate_payload.number_sdp_streams & 1) {
353 i = req->u.allocate_payload.number_sdp_streams - 1;
354 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
358 case DP_QUERY_PAYLOAD:
359 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
361 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
364 case DP_REMOTE_DPCD_READ:
365 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
366 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
368 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
370 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
372 buf[idx] = (req->u.dpcd_read.num_bytes);
376 case DP_REMOTE_DPCD_WRITE:
377 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
378 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
380 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
382 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
384 buf[idx] = (req->u.dpcd_write.num_bytes);
386 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
387 idx += req->u.dpcd_write.num_bytes;
389 case DP_REMOTE_I2C_READ:
390 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
391 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
393 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
394 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
396 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
398 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
399 idx += req->u.i2c_read.transactions[i].num_bytes;
401 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
402 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
405 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
407 buf[idx] = (req->u.i2c_read.num_bytes_read);
411 case DP_REMOTE_I2C_WRITE:
412 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
414 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
416 buf[idx] = (req->u.i2c_write.num_bytes);
418 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
419 idx += req->u.i2c_write.num_bytes;
424 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
426 /* Decode a sideband request we've encoded, mainly used for debugging */
428 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
429 struct drm_dp_sideband_msg_req_body *req)
431 const u8 *buf = raw->msg;
434 req->req_type = buf[idx++] & 0x7f;
435 switch (req->req_type) {
436 case DP_ENUM_PATH_RESOURCES:
437 case DP_POWER_DOWN_PHY:
438 case DP_POWER_UP_PHY:
439 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
441 case DP_ALLOCATE_PAYLOAD:
443 struct drm_dp_allocate_payload *a =
444 &req->u.allocate_payload;
446 a->number_sdp_streams = buf[idx] & 0xf;
447 a->port_number = (buf[idx] >> 4) & 0xf;
449 WARN_ON(buf[++idx] & 0x80);
450 a->vcpi = buf[idx] & 0x7f;
452 a->pbn = buf[++idx] << 8;
453 a->pbn |= buf[++idx];
456 for (i = 0; i < a->number_sdp_streams; i++) {
457 a->sdp_stream_sink[i] =
458 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
462 case DP_QUERY_PAYLOAD:
463 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
464 WARN_ON(buf[++idx] & 0x80);
465 req->u.query_payload.vcpi = buf[idx] & 0x7f;
467 case DP_REMOTE_DPCD_READ:
469 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
471 r->port_number = (buf[idx] >> 4) & 0xf;
473 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
474 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
475 r->dpcd_address |= buf[++idx] & 0xff;
477 r->num_bytes = buf[++idx];
480 case DP_REMOTE_DPCD_WRITE:
482 struct drm_dp_remote_dpcd_write *w =
485 w->port_number = (buf[idx] >> 4) & 0xf;
487 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
488 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
489 w->dpcd_address |= buf[++idx] & 0xff;
491 w->num_bytes = buf[++idx];
493 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
499 case DP_REMOTE_I2C_READ:
501 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
502 struct drm_dp_remote_i2c_read_tx *tx;
505 r->num_transactions = buf[idx] & 0x3;
506 r->port_number = (buf[idx] >> 4) & 0xf;
507 for (i = 0; i < r->num_transactions; i++) {
508 tx = &r->transactions[i];
510 tx->i2c_dev_id = buf[++idx] & 0x7f;
511 tx->num_bytes = buf[++idx];
512 tx->bytes = kmemdup(&buf[++idx],
519 idx += tx->num_bytes;
520 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
521 tx->i2c_transaction_delay = buf[idx] & 0xf;
525 for (i = 0; i < r->num_transactions; i++) {
526 tx = &r->transactions[i];
532 r->read_i2c_device_id = buf[++idx] & 0x7f;
533 r->num_bytes_read = buf[++idx];
536 case DP_REMOTE_I2C_WRITE:
538 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
540 w->port_number = (buf[idx] >> 4) & 0xf;
541 w->write_i2c_device_id = buf[++idx] & 0x7f;
542 w->num_bytes = buf[++idx];
543 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
553 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
556 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
557 int indent, struct drm_printer *printer)
561 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
562 if (req->req_type == DP_LINK_ADDRESS) {
563 /* No contents to print */
564 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
568 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
571 switch (req->req_type) {
572 case DP_ENUM_PATH_RESOURCES:
573 case DP_POWER_DOWN_PHY:
574 case DP_POWER_UP_PHY:
575 P("port=%d\n", req->u.port_num.port_number);
577 case DP_ALLOCATE_PAYLOAD:
578 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
579 req->u.allocate_payload.port_number,
580 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
581 req->u.allocate_payload.number_sdp_streams,
582 req->u.allocate_payload.number_sdp_streams,
583 req->u.allocate_payload.sdp_stream_sink);
585 case DP_QUERY_PAYLOAD:
586 P("port=%d vcpi=%d\n",
587 req->u.query_payload.port_number,
588 req->u.query_payload.vcpi);
590 case DP_REMOTE_DPCD_READ:
591 P("port=%d dpcd_addr=%05x len=%d\n",
592 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
593 req->u.dpcd_read.num_bytes);
595 case DP_REMOTE_DPCD_WRITE:
596 P("port=%d addr=%05x len=%d: %*ph\n",
597 req->u.dpcd_write.port_number,
598 req->u.dpcd_write.dpcd_address,
599 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
600 req->u.dpcd_write.bytes);
602 case DP_REMOTE_I2C_READ:
603 P("port=%d num_tx=%d id=%d size=%d:\n",
604 req->u.i2c_read.port_number,
605 req->u.i2c_read.num_transactions,
606 req->u.i2c_read.read_i2c_device_id,
607 req->u.i2c_read.num_bytes_read);
610 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
611 const struct drm_dp_remote_i2c_read_tx *rtx =
612 &req->u.i2c_read.transactions[i];
614 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
615 i, rtx->i2c_dev_id, rtx->num_bytes,
616 rtx->no_stop_bit, rtx->i2c_transaction_delay,
617 rtx->num_bytes, rtx->bytes);
620 case DP_REMOTE_I2C_WRITE:
621 P("port=%d id=%d size=%d: %*ph\n",
622 req->u.i2c_write.port_number,
623 req->u.i2c_write.write_i2c_device_id,
624 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
625 req->u.i2c_write.bytes);
633 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
636 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
637 const struct drm_dp_sideband_msg_tx *txmsg)
639 struct drm_dp_sideband_msg_req_body req;
644 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
646 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
647 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
648 drm_dp_mst_sideband_tx_state_str(txmsg->state),
649 txmsg->path_msg, buf);
651 ret = drm_dp_decode_sideband_req(txmsg, &req);
653 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
656 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
658 switch (req.req_type) {
659 case DP_REMOTE_DPCD_WRITE:
660 kfree(req.u.dpcd_write.bytes);
662 case DP_REMOTE_I2C_READ:
663 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
664 kfree(req.u.i2c_read.transactions[i].bytes);
666 case DP_REMOTE_I2C_WRITE:
667 kfree(req.u.i2c_write.bytes);
672 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
675 crc4 = drm_dp_msg_data_crc4(msg, len);
679 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
680 struct drm_dp_sideband_msg_tx *raw)
685 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
690 /* this adds a chunk of msg to the builder to get the final msg */
691 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
692 u8 *replybuf, u8 replybuflen, bool hdr)
699 struct drm_dp_sideband_msg_hdr recv_hdr;
700 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
702 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
707 * ignore out-of-order messages or messages that are part of a
710 if (!recv_hdr.somt && !msg->have_somt)
713 /* get length contained in this portion */
714 msg->curchunk_len = recv_hdr.msg_len;
715 msg->curchunk_hdrlen = hdrlen;
717 /* we have already gotten an somt - don't bother parsing */
718 if (recv_hdr.somt && msg->have_somt)
722 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
723 msg->have_somt = true;
726 msg->have_eomt = true;
728 /* copy the bytes for the remainder of this header chunk */
729 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
730 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
732 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
733 msg->curchunk_idx += replybuflen;
736 if (msg->curchunk_idx >= msg->curchunk_len) {
738 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
739 if (crc4 != msg->chunk[msg->curchunk_len - 1])
740 print_hex_dump(KERN_DEBUG, "wrong crc",
741 DUMP_PREFIX_NONE, 16, 1,
742 msg->chunk, msg->curchunk_len, false);
743 /* copy chunk into bigger msg */
744 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
745 msg->curlen += msg->curchunk_len - 1;
750 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
751 struct drm_dp_sideband_msg_reply_body *repmsg)
755 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
757 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
759 if (idx > raw->curlen)
761 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
762 if (raw->msg[idx] & 0x80)
763 repmsg->u.link_addr.ports[i].input_port = 1;
765 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
766 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
769 if (idx > raw->curlen)
771 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
772 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
773 if (repmsg->u.link_addr.ports[i].input_port == 0)
774 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
776 if (idx > raw->curlen)
778 if (repmsg->u.link_addr.ports[i].input_port == 0) {
779 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
781 if (idx > raw->curlen)
783 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
785 if (idx > raw->curlen)
787 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
788 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
792 if (idx > raw->curlen)
798 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
802 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
803 struct drm_dp_sideband_msg_reply_body *repmsg)
806 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
808 if (idx > raw->curlen)
810 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
812 if (idx > raw->curlen)
815 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
818 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
822 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
823 struct drm_dp_sideband_msg_reply_body *repmsg)
826 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
828 if (idx > raw->curlen)
832 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
836 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
837 struct drm_dp_sideband_msg_reply_body *repmsg)
841 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
843 if (idx > raw->curlen)
845 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
848 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
851 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
855 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
856 struct drm_dp_sideband_msg_reply_body *repmsg)
859 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
860 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
862 if (idx > raw->curlen)
864 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
866 if (idx > raw->curlen)
868 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
870 if (idx > raw->curlen)
874 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
878 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
879 struct drm_dp_sideband_msg_reply_body *repmsg)
882 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
884 if (idx > raw->curlen)
886 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
888 if (idx > raw->curlen)
890 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
892 if (idx > raw->curlen)
896 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
900 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
901 struct drm_dp_sideband_msg_reply_body *repmsg)
904 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
906 if (idx > raw->curlen)
908 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
910 if (idx > raw->curlen)
914 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
918 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
919 struct drm_dp_sideband_msg_reply_body *repmsg)
923 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
925 if (idx > raw->curlen) {
926 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
933 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
934 struct drm_dp_sideband_msg_reply_body *msg)
936 memset(msg, 0, sizeof(*msg));
937 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
938 msg->req_type = (raw->msg[0] & 0x7f);
940 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
941 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
942 msg->u.nak.reason = raw->msg[17];
943 msg->u.nak.nak_data = raw->msg[18];
947 switch (msg->req_type) {
948 case DP_LINK_ADDRESS:
949 return drm_dp_sideband_parse_link_address(raw, msg);
950 case DP_QUERY_PAYLOAD:
951 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
952 case DP_REMOTE_DPCD_READ:
953 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
954 case DP_REMOTE_DPCD_WRITE:
955 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
956 case DP_REMOTE_I2C_READ:
957 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
958 case DP_ENUM_PATH_RESOURCES:
959 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
960 case DP_ALLOCATE_PAYLOAD:
961 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
962 case DP_POWER_DOWN_PHY:
963 case DP_POWER_UP_PHY:
964 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
965 case DP_CLEAR_PAYLOAD_ID_TABLE:
966 return true; /* since there's nothing to parse */
968 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
969 drm_dp_mst_req_type_str(msg->req_type));
974 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
975 struct drm_dp_sideband_msg_req_body *msg)
979 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
981 if (idx > raw->curlen)
984 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
986 if (idx > raw->curlen)
989 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
990 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
991 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
992 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
993 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
997 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
1001 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
1002 struct drm_dp_sideband_msg_req_body *msg)
1006 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1008 if (idx > raw->curlen)
1011 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1013 if (idx > raw->curlen)
1016 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1020 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
1024 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
1025 struct drm_dp_sideband_msg_req_body *msg)
1027 memset(msg, 0, sizeof(*msg));
1028 msg->req_type = (raw->msg[0] & 0x7f);
1030 switch (msg->req_type) {
1031 case DP_CONNECTION_STATUS_NOTIFY:
1032 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
1033 case DP_RESOURCE_STATUS_NOTIFY:
1034 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
1036 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
1037 drm_dp_mst_req_type_str(msg->req_type));
1042 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1043 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1045 struct drm_dp_sideband_msg_req_body req;
1047 req.req_type = DP_REMOTE_DPCD_WRITE;
1048 req.u.dpcd_write.port_number = port_num;
1049 req.u.dpcd_write.dpcd_address = offset;
1050 req.u.dpcd_write.num_bytes = num_bytes;
1051 req.u.dpcd_write.bytes = bytes;
1052 drm_dp_encode_sideband_req(&req, msg);
1055 static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1057 struct drm_dp_sideband_msg_req_body req;
1059 req.req_type = DP_LINK_ADDRESS;
1060 drm_dp_encode_sideband_req(&req, msg);
1063 static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1065 struct drm_dp_sideband_msg_req_body req;
1067 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1068 drm_dp_encode_sideband_req(&req, msg);
1072 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1075 struct drm_dp_sideband_msg_req_body req;
1077 req.req_type = DP_ENUM_PATH_RESOURCES;
1078 req.u.port_num.port_number = port_num;
1079 drm_dp_encode_sideband_req(&req, msg);
1080 msg->path_msg = true;
1084 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1086 u8 vcpi, uint16_t pbn,
1087 u8 number_sdp_streams,
1088 u8 *sdp_stream_sink)
1090 struct drm_dp_sideband_msg_req_body req;
1091 memset(&req, 0, sizeof(req));
1092 req.req_type = DP_ALLOCATE_PAYLOAD;
1093 req.u.allocate_payload.port_number = port_num;
1094 req.u.allocate_payload.vcpi = vcpi;
1095 req.u.allocate_payload.pbn = pbn;
1096 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1097 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1098 number_sdp_streams);
1099 drm_dp_encode_sideband_req(&req, msg);
1100 msg->path_msg = true;
1103 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1104 int port_num, bool power_up)
1106 struct drm_dp_sideband_msg_req_body req;
1109 req.req_type = DP_POWER_UP_PHY;
1111 req.req_type = DP_POWER_DOWN_PHY;
1113 req.u.port_num.port_number = port_num;
1114 drm_dp_encode_sideband_req(&req, msg);
1115 msg->path_msg = true;
1118 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1119 struct drm_dp_vcpi *vcpi)
1123 mutex_lock(&mgr->payload_lock);
1124 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1125 if (ret > mgr->max_payloads) {
1127 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
1131 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1132 if (vcpi_ret > mgr->max_payloads) {
1134 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
1138 set_bit(ret, &mgr->payload_mask);
1139 set_bit(vcpi_ret, &mgr->vcpi_mask);
1140 vcpi->vcpi = vcpi_ret + 1;
1141 mgr->proposed_vcpis[ret - 1] = vcpi;
1143 mutex_unlock(&mgr->payload_lock);
1147 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1154 mutex_lock(&mgr->payload_lock);
1155 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
1156 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1158 for (i = 0; i < mgr->max_payloads; i++) {
1159 if (mgr->proposed_vcpis[i] &&
1160 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1161 mgr->proposed_vcpis[i] = NULL;
1162 clear_bit(i + 1, &mgr->payload_mask);
1165 mutex_unlock(&mgr->payload_lock);
1168 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1169 struct drm_dp_sideband_msg_tx *txmsg)
1174 * All updates to txmsg->state are protected by mgr->qlock, and the two
1175 * cases we check here are terminal states. For those the barriers
1176 * provided by the wake_up/wait_event pair are enough.
1178 state = READ_ONCE(txmsg->state);
1179 return (state == DRM_DP_SIDEBAND_TX_RX ||
1180 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1183 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1184 struct drm_dp_sideband_msg_tx *txmsg)
1186 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1189 ret = wait_event_timeout(mgr->tx_waitq,
1190 check_txmsg_state(mgr, txmsg),
1192 mutex_lock(&mstb->mgr->qlock);
1194 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1199 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
1201 /* dump some state */
1205 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1206 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
1207 list_del(&txmsg->next);
1210 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1211 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
1212 mstb->tx_slots[txmsg->seqno] = NULL;
1214 mgr->is_waiting_for_dwn_reply = false;
1218 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1219 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1221 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1223 mutex_unlock(&mgr->qlock);
1225 drm_dp_mst_kick_tx(mgr);
1229 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1231 struct drm_dp_mst_branch *mstb;
1233 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1239 memcpy(mstb->rad, rad, lct / 2);
1240 INIT_LIST_HEAD(&mstb->ports);
1241 kref_init(&mstb->topology_kref);
1242 kref_init(&mstb->malloc_kref);
1246 static void drm_dp_free_mst_branch_device(struct kref *kref)
1248 struct drm_dp_mst_branch *mstb =
1249 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1251 if (mstb->port_parent)
1252 drm_dp_mst_put_port_malloc(mstb->port_parent);
1258 * DOC: Branch device and port refcounting
1260 * Topology refcount overview
1261 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1263 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1264 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1265 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1267 * Topology refcounts are not exposed to drivers, and are handled internally
1268 * by the DP MST helpers. The helpers use them in order to prevent the
1269 * in-memory topology state from being changed in the middle of critical
1270 * operations like changing the internal state of payload allocations. This
1271 * means each branch and port will be considered to be connected to the rest
1272 * of the topology until its topology refcount reaches zero. Additionally,
1273 * for ports this means that their associated &struct drm_connector will stay
1274 * registered with userspace until the port's refcount reaches 0.
1276 * Malloc refcount overview
1277 * ~~~~~~~~~~~~~~~~~~~~~~~~
1279 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1280 * drm_dp_mst_branch allocated even after all of its topology references have
1281 * been dropped, so that the driver or MST helpers can safely access each
1282 * branch's last known state before it was disconnected from the topology.
1283 * When the malloc refcount of a port or branch reaches 0, the memory
1284 * allocation containing the &struct drm_dp_mst_branch or &struct
1285 * drm_dp_mst_port respectively will be freed.
1287 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1288 * to drivers. As of writing this documentation, there are no drivers that
1289 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1290 * helpers. Exposing this API to drivers in a race-free manner would take more
1291 * tweaking of the refcounting scheme, however patches are welcome provided
1292 * there is a legitimate driver usecase for this.
1294 * Refcount relationships in a topology
1295 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1297 * Let's take a look at why the relationship between topology and malloc
1298 * refcounts is designed the way it is.
1300 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1302 * An example of topology and malloc refs in a DP MST topology with two
1303 * active payloads. Topology refcount increments are indicated by solid
1304 * lines, and malloc refcount increments are indicated by dashed lines.
1305 * Each starts from the branch which incremented the refcount, and ends at
1306 * the branch to which the refcount belongs to, i.e. the arrow points the
1307 * same way as the C pointers used to reference a structure.
1309 * As you can see in the above figure, every branch increments the topology
1310 * refcount of its children, and increments the malloc refcount of its
1311 * parent. Additionally, every payload increments the malloc refcount of its
1312 * assigned port by 1.
1314 * So, what would happen if MSTB #3 from the above figure was unplugged from
1315 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1316 * topology would start to look like the figure below.
1318 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1320 * Ports and branch devices which have been released from memory are
1321 * colored grey, and references which have been removed are colored red.
1323 * Whenever a port or branch device's topology refcount reaches zero, it will
1324 * decrement the topology refcounts of all its children, the malloc refcount
1325 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1326 * #4, this means they both have been disconnected from the topology and freed
1327 * from memory. But, because payload #2 is still holding a reference to port
1328 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1329 * is still accessible from memory. This also means port #3 has not yet
1330 * decremented the malloc refcount of MSTB #3, so its &struct
1331 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1332 * malloc refcount reaches 0.
1334 * This relationship is necessary because in order to release payload #2, we
1335 * need to be able to figure out the last relative of port #3 that's still
1336 * connected to the topology. In this case, we would travel up the topology as
1339 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1341 * And finally, remove payload #2 by communicating with port #2 through
1342 * sideband transactions.
1346 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1348 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1350 * Increments &drm_dp_mst_branch.malloc_kref. When
1351 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1352 * will be released and @mstb may no longer be used.
1354 * See also: drm_dp_mst_put_mstb_malloc()
1357 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1359 kref_get(&mstb->malloc_kref);
1360 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1364 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1366 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1368 * Decrements &drm_dp_mst_branch.malloc_kref. When
1369 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1370 * will be released and @mstb may no longer be used.
1372 * See also: drm_dp_mst_get_mstb_malloc()
1375 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1377 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1378 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1381 static void drm_dp_free_mst_port(struct kref *kref)
1383 struct drm_dp_mst_port *port =
1384 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1386 drm_dp_mst_put_mstb_malloc(port->parent);
1391 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1392 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1394 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1395 * reaches 0, the memory allocation for @port will be released and @port may
1396 * no longer be used.
1398 * Because @port could potentially be freed at any time by the DP MST helpers
1399 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1400 * function, drivers that which to make use of &struct drm_dp_mst_port should
1401 * ensure that they grab at least one main malloc reference to their MST ports
1402 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1403 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1405 * See also: drm_dp_mst_put_port_malloc()
1408 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1410 kref_get(&port->malloc_kref);
1411 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1413 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1416 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1417 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1419 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1420 * reaches 0, the memory allocation for @port will be released and @port may
1421 * no longer be used.
1423 * See also: drm_dp_mst_get_port_malloc()
1426 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1428 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1429 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1431 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1433 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1435 #define STACK_DEPTH 8
1437 static noinline void
1438 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1439 struct drm_dp_mst_topology_ref_history *history,
1440 enum drm_dp_mst_topology_ref_type type)
1442 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1443 depot_stack_handle_t backtrace;
1444 ulong stack_entries[STACK_DEPTH];
1448 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1449 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1453 /* Try to find an existing entry for this backtrace */
1454 for (i = 0; i < history->len; i++) {
1455 if (history->entries[i].backtrace == backtrace) {
1456 entry = &history->entries[i];
1461 /* Otherwise add one */
1463 struct drm_dp_mst_topology_ref_entry *new;
1464 int new_len = history->len + 1;
1466 new = krealloc(history->entries, sizeof(*new) * new_len,
1471 entry = &new[history->len];
1472 history->len = new_len;
1473 history->entries = new;
1475 entry->backtrace = backtrace;
1480 entry->ts_nsec = ktime_get_ns();
1484 topology_ref_history_cmp(const void *a, const void *b)
1486 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1488 if (entry_a->ts_nsec > entry_b->ts_nsec)
1490 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1496 static inline const char *
1497 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1499 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1506 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1507 void *ptr, const char *type_str)
1509 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1510 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1519 /* First, sort the list so that it goes from oldest to newest
1522 sort(history->entries, history->len, sizeof(*history->entries),
1523 topology_ref_history_cmp, NULL);
1525 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1528 for (i = 0; i < history->len; i++) {
1529 const struct drm_dp_mst_topology_ref_entry *entry =
1530 &history->entries[i];
1533 u64 ts_nsec = entry->ts_nsec;
1534 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1536 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1537 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1539 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1541 topology_ref_type_to_str(entry->type),
1542 ts_nsec, rem_nsec / 1000, buf);
1545 /* Now free the history, since this is the only time we expose it */
1546 kfree(history->entries);
1551 static __always_inline void
1552 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1554 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1558 static __always_inline void
1559 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1561 __dump_topology_ref_history(&port->topology_ref_history, port,
1565 static __always_inline void
1566 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1567 enum drm_dp_mst_topology_ref_type type)
1569 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1572 static __always_inline void
1573 save_port_topology_ref(struct drm_dp_mst_port *port,
1574 enum drm_dp_mst_topology_ref_type type)
1576 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1580 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1582 mutex_lock(&mgr->topology_ref_history_lock);
1586 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1588 mutex_unlock(&mgr->topology_ref_history_lock);
1592 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1594 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1596 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1598 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1599 #define save_mstb_topology_ref(mstb, type)
1600 #define save_port_topology_ref(port, type)
1603 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1605 struct drm_dp_mst_branch *mstb =
1606 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1607 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1609 drm_dp_mst_dump_mstb_topology_history(mstb);
1611 INIT_LIST_HEAD(&mstb->destroy_next);
1614 * This can get called under mgr->mutex, so we need to perform the
1615 * actual destruction of the mstb in another worker
1617 mutex_lock(&mgr->delayed_destroy_lock);
1618 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1619 mutex_unlock(&mgr->delayed_destroy_lock);
1620 schedule_work(&mgr->delayed_destroy_work);
1624 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1625 * branch device unless it's zero
1626 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1628 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1629 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1630 * reached 0). Holding a topology reference implies that a malloc reference
1631 * will be held to @mstb as long as the user holds the topology reference.
1633 * Care should be taken to ensure that the user has at least one malloc
1634 * reference to @mstb. If you already have a topology reference to @mstb, you
1635 * should use drm_dp_mst_topology_get_mstb() instead.
1638 * drm_dp_mst_topology_get_mstb()
1639 * drm_dp_mst_topology_put_mstb()
1642 * * 1: A topology reference was grabbed successfully
1643 * * 0: @port is no longer in the topology, no reference was grabbed
1645 static int __must_check
1646 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1650 topology_ref_history_lock(mstb->mgr);
1651 ret = kref_get_unless_zero(&mstb->topology_kref);
1653 DRM_DEBUG("mstb %p (%d)\n",
1654 mstb, kref_read(&mstb->topology_kref));
1655 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1658 topology_ref_history_unlock(mstb->mgr);
1664 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1666 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1668 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1669 * not it's already reached 0. This is only valid to use in scenarios where
1670 * you are already guaranteed to have at least one active topology reference
1671 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1674 * drm_dp_mst_topology_try_get_mstb()
1675 * drm_dp_mst_topology_put_mstb()
1677 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1679 topology_ref_history_lock(mstb->mgr);
1681 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1682 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1683 kref_get(&mstb->topology_kref);
1684 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1686 topology_ref_history_unlock(mstb->mgr);
1690 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1692 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1694 * Releases a topology reference from @mstb by decrementing
1695 * &drm_dp_mst_branch.topology_kref.
1698 * drm_dp_mst_topology_try_get_mstb()
1699 * drm_dp_mst_topology_get_mstb()
1702 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1704 topology_ref_history_lock(mstb->mgr);
1706 DRM_DEBUG("mstb %p (%d)\n",
1707 mstb, kref_read(&mstb->topology_kref) - 1);
1708 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1710 topology_ref_history_unlock(mstb->mgr);
1711 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1714 static void drm_dp_destroy_port(struct kref *kref)
1716 struct drm_dp_mst_port *port =
1717 container_of(kref, struct drm_dp_mst_port, topology_kref);
1718 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1720 drm_dp_mst_dump_port_topology_history(port);
1722 /* There's nothing that needs locking to destroy an input port yet */
1724 drm_dp_mst_put_port_malloc(port);
1728 kfree(port->cached_edid);
1731 * we can't destroy the connector here, as we might be holding the
1732 * mode_config.mutex from an EDID retrieval
1734 mutex_lock(&mgr->delayed_destroy_lock);
1735 list_add(&port->next, &mgr->destroy_port_list);
1736 mutex_unlock(&mgr->delayed_destroy_lock);
1737 schedule_work(&mgr->delayed_destroy_work);
1741 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1742 * port unless it's zero
1743 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1745 * Attempts to grab a topology reference to @port, if it hasn't yet been
1746 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1747 * 0). Holding a topology reference implies that a malloc reference will be
1748 * held to @port as long as the user holds the topology reference.
1750 * Care should be taken to ensure that the user has at least one malloc
1751 * reference to @port. If you already have a topology reference to @port, you
1752 * should use drm_dp_mst_topology_get_port() instead.
1755 * drm_dp_mst_topology_get_port()
1756 * drm_dp_mst_topology_put_port()
1759 * * 1: A topology reference was grabbed successfully
1760 * * 0: @port is no longer in the topology, no reference was grabbed
1762 static int __must_check
1763 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1767 topology_ref_history_lock(port->mgr);
1768 ret = kref_get_unless_zero(&port->topology_kref);
1770 DRM_DEBUG("port %p (%d)\n",
1771 port, kref_read(&port->topology_kref));
1772 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1775 topology_ref_history_unlock(port->mgr);
1780 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1781 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1783 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1784 * not it's already reached 0. This is only valid to use in scenarios where
1785 * you are already guaranteed to have at least one active topology reference
1786 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1789 * drm_dp_mst_topology_try_get_port()
1790 * drm_dp_mst_topology_put_port()
1792 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1794 topology_ref_history_lock(port->mgr);
1796 WARN_ON(kref_read(&port->topology_kref) == 0);
1797 kref_get(&port->topology_kref);
1798 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1799 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1801 topology_ref_history_unlock(port->mgr);
1805 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1806 * @port: The &struct drm_dp_mst_port to release the topology reference from
1808 * Releases a topology reference from @port by decrementing
1809 * &drm_dp_mst_port.topology_kref.
1812 * drm_dp_mst_topology_try_get_port()
1813 * drm_dp_mst_topology_get_port()
1815 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1817 topology_ref_history_lock(port->mgr);
1819 DRM_DEBUG("port %p (%d)\n",
1820 port, kref_read(&port->topology_kref) - 1);
1821 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1823 topology_ref_history_unlock(port->mgr);
1824 kref_put(&port->topology_kref, drm_dp_destroy_port);
1827 static struct drm_dp_mst_branch *
1828 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1829 struct drm_dp_mst_branch *to_find)
1831 struct drm_dp_mst_port *port;
1832 struct drm_dp_mst_branch *rmstb;
1834 if (to_find == mstb)
1837 list_for_each_entry(port, &mstb->ports, next) {
1839 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1840 port->mstb, to_find);
1848 static struct drm_dp_mst_branch *
1849 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1850 struct drm_dp_mst_branch *mstb)
1852 struct drm_dp_mst_branch *rmstb = NULL;
1854 mutex_lock(&mgr->lock);
1855 if (mgr->mst_primary) {
1856 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1857 mgr->mst_primary, mstb);
1859 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1862 mutex_unlock(&mgr->lock);
1866 static struct drm_dp_mst_port *
1867 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1868 struct drm_dp_mst_port *to_find)
1870 struct drm_dp_mst_port *port, *mport;
1872 list_for_each_entry(port, &mstb->ports, next) {
1873 if (port == to_find)
1877 mport = drm_dp_mst_topology_get_port_validated_locked(
1878 port->mstb, to_find);
1886 static struct drm_dp_mst_port *
1887 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1888 struct drm_dp_mst_port *port)
1890 struct drm_dp_mst_port *rport = NULL;
1892 mutex_lock(&mgr->lock);
1893 if (mgr->mst_primary) {
1894 rport = drm_dp_mst_topology_get_port_validated_locked(
1895 mgr->mst_primary, port);
1897 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1900 mutex_unlock(&mgr->lock);
1904 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1906 struct drm_dp_mst_port *port;
1909 list_for_each_entry(port, &mstb->ports, next) {
1910 if (port->port_num == port_num) {
1911 ret = drm_dp_mst_topology_try_get_port(port);
1912 return ret ? port : NULL;
1920 * calculate a new RAD for this MST branch device
1921 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1922 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1924 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1927 int parent_lct = port->parent->lct;
1929 int idx = (parent_lct - 1) / 2;
1930 if (parent_lct > 1) {
1931 memcpy(rad, port->parent->rad, idx + 1);
1932 shift = (parent_lct % 2) ? 4 : 0;
1936 rad[idx] |= port->port_num << shift;
1937 return parent_lct + 1;
1940 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
1943 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1944 case DP_PEER_DEVICE_SST_SINK:
1946 case DP_PEER_DEVICE_MST_BRANCHING:
1947 /* For sst branch device */
1957 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
1960 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1961 struct drm_dp_mst_branch *mstb;
1965 if (port->pdt == new_pdt && port->mcs == new_mcs)
1968 /* Teardown the old pdt, if there is one */
1969 if (port->pdt != DP_PEER_DEVICE_NONE) {
1970 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
1972 * If the new PDT would also have an i2c bus,
1973 * don't bother with reregistering it
1975 if (new_pdt != DP_PEER_DEVICE_NONE &&
1976 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
1977 port->pdt = new_pdt;
1978 port->mcs = new_mcs;
1982 /* remove i2c over sideband */
1983 drm_dp_mst_unregister_i2c_bus(&port->aux);
1985 mutex_lock(&mgr->lock);
1986 drm_dp_mst_topology_put_mstb(port->mstb);
1988 mutex_unlock(&mgr->lock);
1992 port->pdt = new_pdt;
1993 port->mcs = new_mcs;
1995 if (port->pdt != DP_PEER_DEVICE_NONE) {
1996 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
1997 /* add i2c over sideband */
1998 ret = drm_dp_mst_register_i2c_bus(&port->aux);
2000 lct = drm_dp_calculate_rad(port, rad);
2001 mstb = drm_dp_add_mst_branch_device(lct, rad);
2004 DRM_ERROR("Failed to create MSTB for port %p",
2009 mutex_lock(&mgr->lock);
2011 mstb->mgr = port->mgr;
2012 mstb->port_parent = port;
2015 * Make sure this port's memory allocation stays
2016 * around until its child MSTB releases it
2018 drm_dp_mst_get_port_malloc(port);
2019 mutex_unlock(&mgr->lock);
2021 /* And make sure we send a link address for this */
2028 port->pdt = DP_PEER_DEVICE_NONE;
2033 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2034 * @aux: Fake sideband AUX CH
2035 * @offset: address of the (first) register to read
2036 * @buffer: buffer to store the register values
2037 * @size: number of bytes in @buffer
2039 * Performs the same functionality for remote devices via
2040 * sideband messaging as drm_dp_dpcd_read() does for local
2041 * devices via actual AUX CH.
2043 * Return: Number of bytes read, or negative error code on failure.
2045 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2046 unsigned int offset, void *buffer, size_t size)
2048 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2051 return drm_dp_send_dpcd_read(port->mgr, port,
2052 offset, size, buffer);
2056 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2057 * @aux: Fake sideband AUX CH
2058 * @offset: address of the (first) register to write
2059 * @buffer: buffer containing the values to write
2060 * @size: number of bytes in @buffer
2062 * Performs the same functionality for remote devices via
2063 * sideband messaging as drm_dp_dpcd_write() does for local
2064 * devices via actual AUX CH.
2066 * Return: number of bytes written on success, negative error code on failure.
2068 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2069 unsigned int offset, void *buffer, size_t size)
2071 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2074 return drm_dp_send_dpcd_write(port->mgr, port,
2075 offset, size, buffer);
2078 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2082 memcpy(mstb->guid, guid, 16);
2084 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2085 if (mstb->port_parent) {
2086 ret = drm_dp_send_dpcd_write(mstb->mgr,
2088 DP_GUID, 16, mstb->guid);
2090 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2091 DP_GUID, mstb->guid, 16);
2095 if (ret < 16 && ret > 0)
2098 return ret == 16 ? 0 : ret;
2101 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2104 size_t proppath_size)
2108 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2109 for (i = 0; i < (mstb->lct - 1); i++) {
2110 int shift = (i % 2) ? 0 : 4;
2111 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2112 snprintf(temp, sizeof(temp), "-%d", port_num);
2113 strlcat(proppath, temp, proppath_size);
2115 snprintf(temp, sizeof(temp), "-%d", pnum);
2116 strlcat(proppath, temp, proppath_size);
2120 * drm_dp_mst_connector_late_register() - Late MST connector registration
2121 * @connector: The MST connector
2122 * @port: The MST port for this connector
2124 * Helper to register the remote aux device for this MST port. Drivers should
2125 * call this from their mst connector's late_register hook to enable MST aux
2128 * Return: 0 on success, negative error code on failure.
2130 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2131 struct drm_dp_mst_port *port)
2133 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2134 port->aux.name, connector->kdev->kobj.name);
2136 port->aux.dev = connector->kdev;
2137 return drm_dp_aux_register_devnode(&port->aux);
2139 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2142 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2143 * @connector: The MST connector
2144 * @port: The MST port for this connector
2146 * Helper to unregister the remote aux device for this MST port, registered by
2147 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2148 * connector's early_unregister hook.
2150 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2151 struct drm_dp_mst_port *port)
2153 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2154 port->aux.name, connector->kdev->kobj.name);
2155 drm_dp_aux_unregister_devnode(&port->aux);
2157 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2160 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2161 struct drm_dp_mst_port *port)
2163 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2167 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2168 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2169 if (!port->connector) {
2174 if (port->pdt != DP_PEER_DEVICE_NONE &&
2175 drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2176 port->cached_edid = drm_get_edid(port->connector,
2178 drm_connector_set_tile_property(port->connector);
2181 drm_connector_register(port->connector);
2185 DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
2189 * Drop a topology reference, and unlink the port from the in-memory topology
2193 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2194 struct drm_dp_mst_port *port)
2196 mutex_lock(&mgr->lock);
2197 port->parent->num_ports--;
2198 list_del(&port->next);
2199 mutex_unlock(&mgr->lock);
2200 drm_dp_mst_topology_put_port(port);
2203 static struct drm_dp_mst_port *
2204 drm_dp_mst_add_port(struct drm_device *dev,
2205 struct drm_dp_mst_topology_mgr *mgr,
2206 struct drm_dp_mst_branch *mstb, u8 port_number)
2208 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2213 kref_init(&port->topology_kref);
2214 kref_init(&port->malloc_kref);
2215 port->parent = mstb;
2216 port->port_num = port_number;
2218 port->aux.name = "DPMST";
2219 port->aux.dev = dev->dev;
2220 port->aux.is_remote = true;
2222 /* initialize the MST downstream port's AUX crc work queue */
2223 drm_dp_remote_aux_init(&port->aux);
2226 * Make sure the memory allocation for our parent branch stays
2227 * around until our own memory allocation is released
2229 drm_dp_mst_get_mstb_malloc(mstb);
2235 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2236 struct drm_device *dev,
2237 struct drm_dp_link_addr_reply_port *port_msg)
2239 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2240 struct drm_dp_mst_port *port;
2241 int old_ddps = 0, ret;
2242 u8 new_pdt = DP_PEER_DEVICE_NONE;
2244 bool created = false, send_link_addr = false, changed = false;
2246 port = drm_dp_get_port(mstb, port_msg->port_number);
2248 port = drm_dp_mst_add_port(dev, mgr, mstb,
2249 port_msg->port_number);
2254 } else if (!port->input && port_msg->input_port && port->connector) {
2255 /* Since port->connector can't be changed here, we create a
2256 * new port if input_port changes from 0 to 1
2258 drm_dp_mst_topology_unlink_port(mgr, port);
2259 drm_dp_mst_topology_put_port(port);
2260 port = drm_dp_mst_add_port(dev, mgr, mstb,
2261 port_msg->port_number);
2266 } else if (port->input && !port_msg->input_port) {
2268 } else if (port->connector) {
2269 /* We're updating a port that's exposed to userspace, so do it
2272 drm_modeset_lock(&mgr->base.lock, NULL);
2274 old_ddps = port->ddps;
2275 changed = port->ddps != port_msg->ddps ||
2277 (port->ldps != port_msg->legacy_device_plug_status ||
2278 port->dpcd_rev != port_msg->dpcd_revision ||
2279 port->mcs != port_msg->mcs ||
2280 port->pdt != port_msg->peer_device_type ||
2281 port->num_sdp_stream_sinks !=
2282 port_msg->num_sdp_stream_sinks));
2285 port->input = port_msg->input_port;
2287 new_pdt = port_msg->peer_device_type;
2288 new_mcs = port_msg->mcs;
2289 port->ddps = port_msg->ddps;
2290 port->ldps = port_msg->legacy_device_plug_status;
2291 port->dpcd_rev = port_msg->dpcd_revision;
2292 port->num_sdp_streams = port_msg->num_sdp_streams;
2293 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2295 /* manage mstb port lists with mgr lock - take a reference
2298 mutex_lock(&mgr->lock);
2299 drm_dp_mst_topology_get_port(port);
2300 list_add(&port->next, &mstb->ports);
2302 mutex_unlock(&mgr->lock);
2306 * Reprobe PBN caps on both hotplug, and when re-probing the link
2307 * for our parent mstb
2309 if (old_ddps != port->ddps || !created) {
2310 if (port->ddps && !port->input) {
2311 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2320 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2322 send_link_addr = true;
2323 } else if (ret < 0) {
2324 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2330 * If this port wasn't just created, then we're reprobing because
2331 * we're coming out of suspend. In this case, always resend the link
2332 * address if there's an MSTB on this port
2334 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2336 send_link_addr = true;
2338 if (port->connector)
2339 drm_modeset_unlock(&mgr->base.lock);
2340 else if (!port->input)
2341 drm_dp_mst_port_add_connector(mstb, port);
2343 if (send_link_addr && port->mstb) {
2344 ret = drm_dp_send_link_address(mgr, port->mstb);
2345 if (ret == 1) /* MSTB below us changed */
2351 /* put reference to this port */
2352 drm_dp_mst_topology_put_port(port);
2356 drm_dp_mst_topology_unlink_port(mgr, port);
2357 if (port->connector)
2358 drm_modeset_unlock(&mgr->base.lock);
2360 drm_dp_mst_topology_put_port(port);
2365 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2366 struct drm_dp_connection_status_notify *conn_stat)
2368 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2369 struct drm_dp_mst_port *port;
2370 int old_ddps, old_input, ret, i;
2373 bool dowork = false, create_connector = false;
2375 port = drm_dp_get_port(mstb, conn_stat->port_number);
2379 if (port->connector) {
2380 if (!port->input && conn_stat->input_port) {
2382 * We can't remove a connector from an already exposed
2383 * port, so just throw the port out and make sure we
2384 * reprobe the link address of it's parent MSTB
2386 drm_dp_mst_topology_unlink_port(mgr, port);
2387 mstb->link_address_sent = false;
2392 /* Locking is only needed if the port's exposed to userspace */
2393 drm_modeset_lock(&mgr->base.lock, NULL);
2394 } else if (port->input && !conn_stat->input_port) {
2395 create_connector = true;
2396 /* Reprobe link address so we get num_sdp_streams */
2397 mstb->link_address_sent = false;
2401 old_ddps = port->ddps;
2402 old_input = port->input;
2403 port->input = conn_stat->input_port;
2404 port->ldps = conn_stat->legacy_device_plug_status;
2405 port->ddps = conn_stat->displayport_device_plug_status;
2407 if (old_ddps != port->ddps) {
2408 if (port->ddps && !port->input)
2409 drm_dp_send_enum_path_resources(mgr, mstb, port);
2414 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2415 new_mcs = conn_stat->message_capability_status;
2416 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2419 } else if (ret < 0) {
2420 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2425 if (!old_input && old_ddps != port->ddps && !port->ddps) {
2426 for (i = 0; i < mgr->max_payloads; i++) {
2427 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2428 struct drm_dp_mst_port *port_validated;
2434 container_of(vcpi, struct drm_dp_mst_port, vcpi);
2436 drm_dp_mst_topology_get_port_validated(mgr, port_validated);
2437 if (!port_validated) {
2438 mutex_lock(&mgr->payload_lock);
2439 vcpi->num_slots = 0;
2440 mutex_unlock(&mgr->payload_lock);
2442 drm_dp_mst_topology_put_port(port_validated);
2447 if (port->connector)
2448 drm_modeset_unlock(&mgr->base.lock);
2449 else if (create_connector)
2450 drm_dp_mst_port_add_connector(mstb, port);
2453 drm_dp_mst_topology_put_port(port);
2455 queue_work(system_long_wq, &mstb->mgr->work);
2458 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2461 struct drm_dp_mst_branch *mstb;
2462 struct drm_dp_mst_port *port;
2464 /* find the port by iterating down */
2466 mutex_lock(&mgr->lock);
2467 mstb = mgr->mst_primary;
2472 for (i = 0; i < lct - 1; i++) {
2473 int shift = (i % 2) ? 0 : 4;
2474 int port_num = (rad[i / 2] >> shift) & 0xf;
2476 list_for_each_entry(port, &mstb->ports, next) {
2477 if (port->port_num == port_num) {
2480 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
2488 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2492 mutex_unlock(&mgr->lock);
2496 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2497 struct drm_dp_mst_branch *mstb,
2498 const uint8_t *guid)
2500 struct drm_dp_mst_branch *found_mstb;
2501 struct drm_dp_mst_port *port;
2503 if (memcmp(mstb->guid, guid, 16) == 0)
2507 list_for_each_entry(port, &mstb->ports, next) {
2511 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2520 static struct drm_dp_mst_branch *
2521 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2522 const uint8_t *guid)
2524 struct drm_dp_mst_branch *mstb;
2527 /* find the port by iterating down */
2528 mutex_lock(&mgr->lock);
2530 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2532 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2537 mutex_unlock(&mgr->lock);
2541 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2542 struct drm_dp_mst_branch *mstb)
2544 struct drm_dp_mst_port *port;
2546 bool changed = false;
2548 if (!mstb->link_address_sent) {
2549 ret = drm_dp_send_link_address(mgr, mstb);
2556 list_for_each_entry(port, &mstb->ports, next) {
2557 struct drm_dp_mst_branch *mstb_child = NULL;
2559 if (port->input || !port->ddps)
2563 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2567 ret = drm_dp_check_and_send_link_address(mgr,
2569 drm_dp_mst_topology_put_mstb(mstb_child);
2580 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2582 struct drm_dp_mst_topology_mgr *mgr =
2583 container_of(work, struct drm_dp_mst_topology_mgr, work);
2584 struct drm_device *dev = mgr->dev;
2585 struct drm_dp_mst_branch *mstb;
2587 bool clear_payload_id_table;
2589 mutex_lock(&mgr->probe_lock);
2591 mutex_lock(&mgr->lock);
2592 clear_payload_id_table = !mgr->payload_id_table_cleared;
2593 mgr->payload_id_table_cleared = true;
2595 mstb = mgr->mst_primary;
2597 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2601 mutex_unlock(&mgr->lock);
2603 mutex_unlock(&mgr->probe_lock);
2608 * Certain branch devices seem to incorrectly report an available_pbn
2609 * of 0 on downstream sinks, even after clearing the
2610 * DP_PAYLOAD_ALLOCATE_* registers in
2611 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2612 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2613 * things work again.
2615 if (clear_payload_id_table) {
2616 DRM_DEBUG_KMS("Clearing payload ID table\n");
2617 drm_dp_send_clear_payload_id_table(mgr, mstb);
2620 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2621 drm_dp_mst_topology_put_mstb(mstb);
2623 mutex_unlock(&mgr->probe_lock);
2625 drm_kms_helper_hotplug_event(dev);
2628 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2633 if (memchr_inv(guid, 0, 16))
2636 salt = get_jiffies_64();
2638 memcpy(&guid[0], &salt, sizeof(u64));
2639 memcpy(&guid[8], &salt, sizeof(u64));
2644 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2645 u8 port_num, u32 offset, u8 num_bytes)
2647 struct drm_dp_sideband_msg_req_body req;
2649 req.req_type = DP_REMOTE_DPCD_READ;
2650 req.u.dpcd_read.port_number = port_num;
2651 req.u.dpcd_read.dpcd_address = offset;
2652 req.u.dpcd_read.num_bytes = num_bytes;
2653 drm_dp_encode_sideband_req(&req, msg);
2656 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2657 bool up, u8 *msg, int len)
2660 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2661 int tosend, total, offset;
2668 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2670 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2673 if (ret != tosend) {
2674 if (ret == -EIO && retries < 5) {
2678 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
2684 } while (total > 0);
2688 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2689 struct drm_dp_sideband_msg_tx *txmsg)
2691 struct drm_dp_mst_branch *mstb = txmsg->dst;
2694 /* both msg slots are full */
2695 if (txmsg->seqno == -1) {
2696 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
2697 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
2700 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
2701 txmsg->seqno = mstb->last_seqno;
2702 mstb->last_seqno ^= 1;
2703 } else if (mstb->tx_slots[0] == NULL)
2707 mstb->tx_slots[txmsg->seqno] = txmsg;
2710 req_type = txmsg->msg[0] & 0x7f;
2711 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2712 req_type == DP_RESOURCE_STATUS_NOTIFY)
2716 hdr->path_msg = txmsg->path_msg;
2717 hdr->lct = mstb->lct;
2718 hdr->lcr = mstb->lct - 1;
2720 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
2721 hdr->seqno = txmsg->seqno;
2725 * process a single block of the next message in the sideband queue
2727 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2728 struct drm_dp_sideband_msg_tx *txmsg,
2732 struct drm_dp_sideband_msg_hdr hdr;
2733 int len, space, idx, tosend;
2736 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2738 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
2740 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2743 /* make hdr from dst mst - for replies use seqno
2744 otherwise assign one */
2745 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2749 /* amount left to send in this message */
2750 len = txmsg->cur_len - txmsg->cur_offset;
2752 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2753 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2755 tosend = min(len, space);
2756 if (len == txmsg->cur_len)
2762 hdr.msg_len = tosend + 1;
2763 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2764 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2765 /* add crc at end */
2766 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2769 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2770 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2771 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2773 drm_printf(&p, "sideband msg failed to send\n");
2774 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2778 txmsg->cur_offset += tosend;
2779 if (txmsg->cur_offset == txmsg->cur_len) {
2780 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2786 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2788 struct drm_dp_sideband_msg_tx *txmsg;
2791 WARN_ON(!mutex_is_locked(&mgr->qlock));
2793 /* construct a chunk from the first msg in the tx_msg queue */
2794 if (list_empty(&mgr->tx_msg_downq))
2797 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
2798 ret = process_single_tx_qlock(mgr, txmsg, false);
2800 /* txmsg is sent it should be in the slots now */
2801 mgr->is_waiting_for_dwn_reply = true;
2802 list_del(&txmsg->next);
2804 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2805 mgr->is_waiting_for_dwn_reply = false;
2806 list_del(&txmsg->next);
2807 if (txmsg->seqno != -1)
2808 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2809 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2810 wake_up_all(&mgr->tx_waitq);
2814 /* called holding qlock */
2815 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2816 struct drm_dp_sideband_msg_tx *txmsg)
2820 /* construct a chunk from the first msg in the tx_msg queue */
2821 ret = process_single_tx_qlock(mgr, txmsg, true);
2824 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2826 if (txmsg->seqno != -1) {
2827 WARN_ON((unsigned int)txmsg->seqno >
2828 ARRAY_SIZE(txmsg->dst->tx_slots));
2829 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2833 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2834 struct drm_dp_sideband_msg_tx *txmsg)
2836 mutex_lock(&mgr->qlock);
2837 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2839 if (drm_debug_enabled(DRM_UT_DP)) {
2840 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2842 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2845 if (list_is_singular(&mgr->tx_msg_downq) &&
2846 !mgr->is_waiting_for_dwn_reply)
2847 process_single_down_tx_qlock(mgr);
2848 mutex_unlock(&mgr->qlock);
2852 drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
2854 struct drm_dp_link_addr_reply_port *port_reply;
2857 for (i = 0; i < reply->nports; i++) {
2858 port_reply = &reply->ports[i];
2859 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2861 port_reply->input_port,
2862 port_reply->peer_device_type,
2863 port_reply->port_number,
2864 port_reply->dpcd_revision,
2867 port_reply->legacy_device_plug_status,
2868 port_reply->num_sdp_streams,
2869 port_reply->num_sdp_stream_sinks);
2873 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2874 struct drm_dp_mst_branch *mstb)
2876 struct drm_dp_sideband_msg_tx *txmsg;
2877 struct drm_dp_link_address_ack_reply *reply;
2878 struct drm_dp_mst_port *port, *tmp;
2879 int i, ret, port_mask = 0;
2880 bool changed = false;
2882 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2887 build_link_address(txmsg);
2889 mstb->link_address_sent = true;
2890 drm_dp_queue_down_tx(mgr, txmsg);
2892 /* FIXME: Actually do some real error handling here */
2893 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2895 DRM_ERROR("Sending link address failed with %d\n", ret);
2898 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2899 DRM_ERROR("link address NAK received\n");
2904 reply = &txmsg->reply.u.link_addr;
2905 DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
2906 drm_dp_dump_link_address(reply);
2908 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2912 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2913 DRM_ERROR("GUID check on %s failed: %d\n",
2918 for (i = 0; i < reply->nports; i++) {
2919 port_mask |= BIT(reply->ports[i].port_number);
2920 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2928 /* Prune any ports that are currently a part of mstb in our in-memory
2929 * topology, but were not seen in this link address. Usually this
2930 * means that they were removed while the topology was out of sync,
2931 * e.g. during suspend/resume
2933 mutex_lock(&mgr->lock);
2934 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2935 if (port_mask & BIT(port->port_num))
2938 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2940 list_del(&port->next);
2941 drm_dp_mst_topology_put_port(port);
2944 mutex_unlock(&mgr->lock);
2948 mstb->link_address_sent = false;
2950 return ret < 0 ? ret : changed;
2953 void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2954 struct drm_dp_mst_branch *mstb)
2956 struct drm_dp_sideband_msg_tx *txmsg;
2959 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2964 build_clear_payload_id_table(txmsg);
2966 drm_dp_queue_down_tx(mgr, txmsg);
2968 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2969 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2970 DRM_DEBUG_KMS("clear payload table id nak received\n");
2976 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2977 struct drm_dp_mst_branch *mstb,
2978 struct drm_dp_mst_port *port)
2980 struct drm_dp_enum_path_resources_ack_reply *path_res;
2981 struct drm_dp_sideband_msg_tx *txmsg;
2984 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2989 build_enum_path_resources(txmsg, port->port_num);
2991 drm_dp_queue_down_tx(mgr, txmsg);
2993 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2996 path_res = &txmsg->reply.u.path_resources;
2998 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2999 DRM_DEBUG_KMS("enum path resources nak received\n");
3001 if (port->port_num != path_res->port_number)
3002 DRM_ERROR("got incorrect port in response\n");
3004 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
3005 path_res->port_number,
3006 path_res->full_payload_bw_number,
3007 path_res->avail_payload_bw_number);
3010 * If something changed, make sure we send a
3013 if (port->full_pbn != path_res->full_payload_bw_number ||
3014 port->fec_capable != path_res->fec_capable)
3017 port->full_pbn = path_res->full_payload_bw_number;
3018 port->fec_capable = path_res->fec_capable;
3026 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3028 if (!mstb->port_parent)
3031 if (mstb->port_parent->mstb != mstb)
3032 return mstb->port_parent;
3034 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3038 * Searches upwards in the topology starting from mstb to try to find the
3039 * closest available parent of mstb that's still connected to the rest of the
3040 * topology. This can be used in order to perform operations like releasing
3041 * payloads, where the branch device which owned the payload may no longer be
3042 * around and thus would require that the payload on the last living relative
3045 static struct drm_dp_mst_branch *
3046 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3047 struct drm_dp_mst_branch *mstb,
3050 struct drm_dp_mst_branch *rmstb = NULL;
3051 struct drm_dp_mst_port *found_port;
3053 mutex_lock(&mgr->lock);
3054 if (!mgr->mst_primary)
3058 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3062 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3063 rmstb = found_port->parent;
3064 *port_num = found_port->port_num;
3066 /* Search again, starting from this parent */
3067 mstb = found_port->parent;
3071 mutex_unlock(&mgr->lock);
3075 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3076 struct drm_dp_mst_port *port,
3080 struct drm_dp_sideband_msg_tx *txmsg;
3081 struct drm_dp_mst_branch *mstb;
3083 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3086 port_num = port->port_num;
3087 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3089 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3097 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3103 for (i = 0; i < port->num_sdp_streams; i++)
3107 build_allocate_payload(txmsg, port_num,
3109 pbn, port->num_sdp_streams, sinks);
3111 drm_dp_queue_down_tx(mgr, txmsg);
3114 * FIXME: there is a small chance that between getting the last
3115 * connected mstb and sending the payload message, the last connected
3116 * mstb could also be removed from the topology. In the future, this
3117 * needs to be fixed by restarting the
3118 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3119 * timeout if the topology is still connected to the system.
3121 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3123 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3130 drm_dp_mst_topology_put_mstb(mstb);
3134 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3135 struct drm_dp_mst_port *port, bool power_up)
3137 struct drm_dp_sideband_msg_tx *txmsg;
3140 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3144 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3146 drm_dp_mst_topology_put_port(port);
3150 txmsg->dst = port->parent;
3151 build_power_updown_phy(txmsg, port->port_num, power_up);
3152 drm_dp_queue_down_tx(mgr, txmsg);
3154 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3156 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3162 drm_dp_mst_topology_put_port(port);
3166 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3168 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3170 struct drm_dp_payload *payload)
3174 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3176 payload->payload_state = 0;
3179 payload->payload_state = DP_PAYLOAD_LOCAL;
3183 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3184 struct drm_dp_mst_port *port,
3186 struct drm_dp_payload *payload)
3189 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3192 payload->payload_state = DP_PAYLOAD_REMOTE;
3196 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3197 struct drm_dp_mst_port *port,
3199 struct drm_dp_payload *payload)
3201 DRM_DEBUG_KMS("\n");
3202 /* it's okay for these to fail */
3204 drm_dp_payload_send_msg(mgr, port, id, 0);
3207 drm_dp_dpcd_write_payload(mgr, id, payload);
3208 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3212 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3214 struct drm_dp_payload *payload)
3216 payload->payload_state = 0;
3221 * drm_dp_update_payload_part1() - Execute payload update part 1
3222 * @mgr: manager to use.
3224 * This iterates over all proposed virtual channels, and tries to
3225 * allocate space in the link for them. For 0->slots transitions,
3226 * this step just writes the VCPI to the MST device. For slots->0
3227 * transitions, this writes the updated VCPIs and removes the
3228 * remote VC payloads.
3230 * after calling this the driver should generate ACT and payload
3233 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3235 struct drm_dp_payload req_payload;
3236 struct drm_dp_mst_port *port;
3240 mutex_lock(&mgr->payload_lock);
3241 for (i = 0; i < mgr->max_payloads; i++) {
3242 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3243 struct drm_dp_payload *payload = &mgr->payloads[i];
3244 bool put_port = false;
3246 /* solve the current payloads - compare to the hw ones
3247 - update the hw view */
3248 req_payload.start_slot = cur_slots;
3250 port = container_of(vcpi, struct drm_dp_mst_port,
3253 /* Validated ports don't matter if we're releasing
3256 if (vcpi->num_slots) {
3257 port = drm_dp_mst_topology_get_port_validated(
3260 mutex_unlock(&mgr->payload_lock);
3266 req_payload.num_slots = vcpi->num_slots;
3267 req_payload.vcpi = vcpi->vcpi;
3270 req_payload.num_slots = 0;
3273 payload->start_slot = req_payload.start_slot;
3274 /* work out what is required to happen with this payload */
3275 if (payload->num_slots != req_payload.num_slots) {
3277 /* need to push an update for this payload */
3278 if (req_payload.num_slots) {
3279 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3281 payload->num_slots = req_payload.num_slots;
3282 payload->vcpi = req_payload.vcpi;
3284 } else if (payload->num_slots) {
3285 payload->num_slots = 0;
3286 drm_dp_destroy_payload_step1(mgr, port,
3289 req_payload.payload_state =
3290 payload->payload_state;
3291 payload->start_slot = 0;
3293 payload->payload_state = req_payload.payload_state;
3295 cur_slots += req_payload.num_slots;
3298 drm_dp_mst_topology_put_port(port);
3301 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3302 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3307 DRM_DEBUG_KMS("removing payload %d\n", i);
3308 for (j = i; j < mgr->max_payloads - 1; j++) {
3309 mgr->payloads[j] = mgr->payloads[j + 1];
3310 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3312 if (mgr->proposed_vcpis[j] &&
3313 mgr->proposed_vcpis[j]->num_slots) {
3314 set_bit(j + 1, &mgr->payload_mask);
3316 clear_bit(j + 1, &mgr->payload_mask);
3320 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3321 sizeof(struct drm_dp_payload));
3322 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3323 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3325 mutex_unlock(&mgr->payload_lock);
3329 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3332 * drm_dp_update_payload_part2() - Execute payload update part 2
3333 * @mgr: manager to use.
3335 * This iterates over all proposed virtual channels, and tries to
3336 * allocate space in the link for them. For 0->slots transitions,
3337 * this step writes the remote VC payload commands. For slots->0
3338 * this just resets some internal state.
3340 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3342 struct drm_dp_mst_port *port;
3345 mutex_lock(&mgr->payload_lock);
3346 for (i = 0; i < mgr->max_payloads; i++) {
3348 if (!mgr->proposed_vcpis[i])
3351 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3353 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
3354 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3355 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3356 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3357 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3360 mutex_unlock(&mgr->payload_lock);
3364 mutex_unlock(&mgr->payload_lock);
3367 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3369 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3370 struct drm_dp_mst_port *port,
3371 int offset, int size, u8 *bytes)
3374 struct drm_dp_sideband_msg_tx *txmsg;
3375 struct drm_dp_mst_branch *mstb;
3377 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3381 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3387 build_dpcd_read(txmsg, port->port_num, offset, size);
3388 txmsg->dst = port->parent;
3390 drm_dp_queue_down_tx(mgr, txmsg);
3392 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3396 /* DPCD read should never be NACKed */
3397 if (txmsg->reply.reply_type == 1) {
3398 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3399 mstb, port->port_num, offset, size);
3404 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3409 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3411 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3416 drm_dp_mst_topology_put_mstb(mstb);
3421 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3422 struct drm_dp_mst_port *port,
3423 int offset, int size, u8 *bytes)
3426 struct drm_dp_sideband_msg_tx *txmsg;
3427 struct drm_dp_mst_branch *mstb;
3429 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3433 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3439 build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3442 drm_dp_queue_down_tx(mgr, txmsg);
3444 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3445 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3450 drm_dp_mst_topology_put_mstb(mstb);
3454 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3456 struct drm_dp_sideband_msg_reply_body reply;
3458 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3459 reply.req_type = req_type;
3460 drm_dp_encode_sideband_reply(&reply, msg);
3464 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3465 struct drm_dp_mst_branch *mstb,
3466 int req_type, int seqno, bool broadcast)
3468 struct drm_dp_sideband_msg_tx *txmsg;
3470 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3475 txmsg->seqno = seqno;
3476 drm_dp_encode_up_ack_reply(txmsg, req_type);
3478 mutex_lock(&mgr->qlock);
3480 process_single_up_tx_qlock(mgr, txmsg);
3482 mutex_unlock(&mgr->qlock);
3488 static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
3490 if (dp_link_bw == 0 || dp_link_count == 0)
3491 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3492 dp_link_bw, dp_link_count);
3494 return dp_link_bw * dp_link_count / 2;
3498 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3499 * @mgr: manager to set state for
3500 * @mst_state: true to enable MST on this connector - false to disable.
3502 * This is called by the driver when it detects an MST capable device plugged
3503 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3505 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3508 struct drm_dp_mst_branch *mstb = NULL;
3510 mutex_lock(&mgr->payload_lock);
3511 mutex_lock(&mgr->lock);
3512 if (mst_state == mgr->mst_state)
3515 mgr->mst_state = mst_state;
3516 /* set the device into MST mode */
3518 struct drm_dp_payload reset_pay;
3520 WARN_ON(mgr->mst_primary);
3523 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
3524 if (ret != DP_RECEIVER_CAP_SIZE) {
3525 DRM_DEBUG_KMS("failed to read DPCD\n");
3529 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
3530 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
3531 if (mgr->pbn_div == 0) {
3536 /* add initial branch device at LCT 1 */
3537 mstb = drm_dp_add_mst_branch_device(1, NULL);
3544 /* give this the main reference */
3545 mgr->mst_primary = mstb;
3546 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3548 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3551 DP_UPSTREAM_IS_SRC);
3555 reset_pay.start_slot = 0;
3556 reset_pay.num_slots = 0x3f;
3557 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3559 queue_work(system_long_wq, &mgr->work);
3563 /* disable MST on the device */
3564 mstb = mgr->mst_primary;
3565 mgr->mst_primary = NULL;
3566 /* this can fail if the device is gone */
3567 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3569 memset(mgr->payloads, 0,
3570 mgr->max_payloads * sizeof(mgr->payloads[0]));
3571 memset(mgr->proposed_vcpis, 0,
3572 mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
3573 mgr->payload_mask = 0;
3574 set_bit(0, &mgr->payload_mask);
3576 mgr->payload_id_table_cleared = false;
3580 mutex_unlock(&mgr->lock);
3581 mutex_unlock(&mgr->payload_lock);
3583 drm_dp_mst_topology_put_mstb(mstb);
3587 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3590 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3592 struct drm_dp_mst_port *port;
3594 /* The link address will need to be re-sent on resume */
3595 mstb->link_address_sent = false;
3597 list_for_each_entry(port, &mstb->ports, next)
3599 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3603 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3604 * @mgr: manager to suspend
3606 * This function tells the MST device that we can't handle UP messages
3607 * anymore. This should stop it from sending any since we are suspended.
3609 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3611 mutex_lock(&mgr->lock);
3612 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3613 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3614 mutex_unlock(&mgr->lock);
3615 flush_work(&mgr->up_req_work);
3616 flush_work(&mgr->work);
3617 flush_work(&mgr->delayed_destroy_work);
3619 mutex_lock(&mgr->lock);
3620 if (mgr->mst_state && mgr->mst_primary)
3621 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3622 mutex_unlock(&mgr->lock);
3624 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3627 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3628 * @mgr: manager to resume
3629 * @sync: whether or not to perform topology reprobing synchronously
3631 * This will fetch DPCD and see if the device is still there,
3632 * if it is, it will rewrite the MSTM control bits, and return.
3634 * If the device fails this returns -1, and the driver should do
3635 * a full MST reprobe, in case we were undocked.
3637 * During system resume (where it is assumed that the driver will be calling
3638 * drm_atomic_helper_resume()) this function should be called beforehand with
3639 * @sync set to true. In contexts like runtime resume where the driver is not
3640 * expected to be calling drm_atomic_helper_resume(), this function should be
3641 * called with @sync set to false in order to avoid deadlocking.
3643 * Returns: -1 if the MST topology was removed while we were suspended, 0
3646 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3652 mutex_lock(&mgr->lock);
3653 if (!mgr->mst_primary)
3656 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3657 DP_RECEIVER_CAP_SIZE);
3658 if (ret != DP_RECEIVER_CAP_SIZE) {
3659 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3663 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3666 DP_UPSTREAM_IS_SRC);
3668 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3672 /* Some hubs forget their guids after they resume */
3673 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3675 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3679 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3681 DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
3686 * For the final step of resuming the topology, we need to bring the
3687 * state of our in-memory topology back into sync with reality. So,
3688 * restart the probing process as if we're probing a new hub
3690 queue_work(system_long_wq, &mgr->work);
3691 mutex_unlock(&mgr->lock);
3694 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3695 flush_work(&mgr->work);
3701 mutex_unlock(&mgr->lock);
3704 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3706 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
3710 int replylen, curreply;
3712 struct drm_dp_sideband_msg_rx *msg;
3713 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
3714 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3716 len = min(mgr->max_dpcd_transaction_bytes, 16);
3717 ret = drm_dp_dpcd_read(mgr->aux, basereg,
3720 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
3723 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
3725 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
3728 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
3732 while (replylen > 0) {
3733 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3734 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3737 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3742 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
3744 DRM_DEBUG_KMS("failed to build sideband msg\n");
3754 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3756 struct drm_dp_sideband_msg_tx *txmsg;
3757 struct drm_dp_mst_branch *mstb;
3758 struct drm_dp_sideband_msg_hdr *hdr = &mgr->down_rep_recv.initial_hdr;
3761 if (!drm_dp_get_one_sb_msg(mgr, false))
3762 goto clear_down_rep_recv;
3764 if (!mgr->down_rep_recv.have_eomt)
3767 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3769 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3771 goto clear_down_rep_recv;
3774 /* find the message */
3776 mutex_lock(&mgr->qlock);
3777 txmsg = mstb->tx_slots[slot];
3778 /* remove from slots */
3779 mutex_unlock(&mgr->qlock);
3782 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3783 mstb, hdr->seqno, hdr->lct, hdr->rad[0],
3784 mgr->down_rep_recv.msg[0]);
3788 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
3790 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3791 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3792 txmsg->reply.req_type,
3793 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3794 txmsg->reply.u.nak.reason,
3795 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3796 txmsg->reply.u.nak.nak_data);
3798 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3799 drm_dp_mst_topology_put_mstb(mstb);
3801 mutex_lock(&mgr->qlock);
3802 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3803 mstb->tx_slots[slot] = NULL;
3804 mgr->is_waiting_for_dwn_reply = false;
3805 mutex_unlock(&mgr->qlock);
3807 wake_up_all(&mgr->tx_waitq);
3812 drm_dp_mst_topology_put_mstb(mstb);
3813 clear_down_rep_recv:
3814 mutex_lock(&mgr->qlock);
3815 mgr->is_waiting_for_dwn_reply = false;
3816 mutex_unlock(&mgr->qlock);
3817 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3823 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3824 struct drm_dp_pending_up_req *up_req)
3826 struct drm_dp_mst_branch *mstb = NULL;
3827 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3828 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3829 bool hotplug = false;
3831 if (hdr->broadcast) {
3832 const u8 *guid = NULL;
3834 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3835 guid = msg->u.conn_stat.guid;
3836 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3837 guid = msg->u.resource_stat.guid;
3840 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3842 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3846 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3851 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3852 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3853 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3857 drm_dp_mst_topology_put_mstb(mstb);
3861 static void drm_dp_mst_up_req_work(struct work_struct *work)
3863 struct drm_dp_mst_topology_mgr *mgr =
3864 container_of(work, struct drm_dp_mst_topology_mgr,
3866 struct drm_dp_pending_up_req *up_req;
3867 bool send_hotplug = false;
3869 mutex_lock(&mgr->probe_lock);
3871 mutex_lock(&mgr->up_req_lock);
3872 up_req = list_first_entry_or_null(&mgr->up_req_list,
3873 struct drm_dp_pending_up_req,
3876 list_del(&up_req->next);
3877 mutex_unlock(&mgr->up_req_lock);
3882 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3885 mutex_unlock(&mgr->probe_lock);
3888 drm_kms_helper_hotplug_event(mgr->dev);
3891 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3893 struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr;
3894 struct drm_dp_pending_up_req *up_req;
3897 if (!drm_dp_get_one_sb_msg(mgr, true))
3900 if (!mgr->up_req_recv.have_eomt)
3903 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
3905 DRM_ERROR("Not enough memory to process MST up req\n");
3908 INIT_LIST_HEAD(&up_req->next);
3911 drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
3913 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
3914 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
3915 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3916 up_req->msg.req_type);
3921 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
3924 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
3925 const struct drm_dp_connection_status_notify *conn_stat =
3926 &up_req->msg.u.conn_stat;
3928 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3929 conn_stat->port_number,
3930 conn_stat->legacy_device_plug_status,
3931 conn_stat->displayport_device_plug_status,
3932 conn_stat->message_capability_status,
3933 conn_stat->input_port,
3934 conn_stat->peer_device_type);
3935 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3936 const struct drm_dp_resource_status_notify *res_stat =
3937 &up_req->msg.u.resource_stat;
3939 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3940 res_stat->port_number,
3941 res_stat->available_pbn);
3945 mutex_lock(&mgr->up_req_lock);
3946 list_add_tail(&up_req->next, &mgr->up_req_list);
3947 mutex_unlock(&mgr->up_req_lock);
3948 queue_work(system_long_wq, &mgr->up_req_work);
3951 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3956 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3957 * @mgr: manager to notify irq for.
3958 * @esi: 4 bytes from SINK_COUNT_ESI
3959 * @handled: whether the hpd interrupt was consumed or not
3961 * This should be called from the driver when it detects a short IRQ,
3962 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3963 * topology manager will process the sideband messages received as a result
3966 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3973 if (sc != mgr->sink_count) {
3974 mgr->sink_count = sc;
3978 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3979 ret = drm_dp_mst_handle_down_rep(mgr);
3983 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3984 ret |= drm_dp_mst_handle_up_req(mgr);
3988 drm_dp_mst_kick_tx(mgr);
3991 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
3994 * drm_dp_mst_detect_port() - get connection status for an MST port
3995 * @connector: DRM connector for this port
3996 * @ctx: The acquisition context to use for grabbing locks
3997 * @mgr: manager for this port
3998 * @port: pointer to a port
4000 * This returns the current connection state for a port.
4003 drm_dp_mst_detect_port(struct drm_connector *connector,
4004 struct drm_modeset_acquire_ctx *ctx,
4005 struct drm_dp_mst_topology_mgr *mgr,
4006 struct drm_dp_mst_port *port)
4010 /* we need to search for the port in the mgr in case it's gone */
4011 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4013 return connector_status_disconnected;
4015 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4019 ret = connector_status_disconnected;
4024 switch (port->pdt) {
4025 case DP_PEER_DEVICE_NONE:
4026 case DP_PEER_DEVICE_MST_BRANCHING:
4028 ret = connector_status_connected;
4031 case DP_PEER_DEVICE_SST_SINK:
4032 ret = connector_status_connected;
4033 /* for logical ports - cache the EDID */
4034 if (port->port_num >= 8 && !port->cached_edid) {
4035 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4038 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4040 ret = connector_status_connected;
4044 drm_dp_mst_topology_put_port(port);
4047 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4050 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
4051 * @mgr: manager for this port
4052 * @port: unverified pointer to a port.
4054 * This returns whether the port supports audio or not.
4056 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
4057 struct drm_dp_mst_port *port)
4061 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4064 ret = port->has_audio;
4065 drm_dp_mst_topology_put_port(port);
4068 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
4071 * drm_dp_mst_get_edid() - get EDID for an MST port
4072 * @connector: toplevel connector to get EDID for
4073 * @mgr: manager for this port
4074 * @port: unverified pointer to a port.
4076 * This returns an EDID for the port connected to a connector,
4077 * It validates the pointer still exists so the caller doesn't require a
4080 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4082 struct edid *edid = NULL;
4084 /* we need to search for the port in the mgr in case it's gone */
4085 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4089 if (port->cached_edid)
4090 edid = drm_edid_duplicate(port->cached_edid);
4092 edid = drm_get_edid(connector, &port->aux.ddc);
4094 port->has_audio = drm_detect_monitor_audio(edid);
4095 drm_dp_mst_topology_put_port(port);
4098 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4101 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4102 * @mgr: manager to use
4103 * @pbn: payload bandwidth to convert into slots.
4105 * Calculate the number of VCPI slots that will be required for the given PBN
4106 * value. This function is deprecated, and should not be used in atomic
4110 * The total slots required for this port, or error.
4112 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4117 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4119 /* max. time slots - one slot for MTP header */
4124 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4126 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4127 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4131 /* max. time slots - one slot for MTP header */
4136 vcpi->aligned_pbn = slots * mgr->pbn_div;
4137 vcpi->num_slots = slots;
4139 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4146 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4147 * @state: global atomic state
4148 * @mgr: MST topology manager for the port
4149 * @port: port to find vcpi slots for
4150 * @pbn: bandwidth required for the mode in PBN
4151 * @pbn_div: divider for DSC mode that takes FEC into account
4153 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4154 * may have had. Any atomic drivers which support MST must call this function
4155 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4156 * current VCPI allocation for the new state, but only when
4157 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4158 * to ensure compatibility with userspace applications that still use the
4159 * legacy modesetting UAPI.
4161 * Allocations set by this function are not checked against the bandwidth
4162 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4164 * Additionally, it is OK to call this function multiple times on the same
4165 * @port as needed. It is not OK however, to call this function and
4166 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4169 * drm_dp_atomic_release_vcpi_slots()
4170 * drm_dp_mst_atomic_check()
4173 * Total slots in the atomic state assigned for this port, or a negative error
4174 * code if the port no longer exists
4176 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4177 struct drm_dp_mst_topology_mgr *mgr,
4178 struct drm_dp_mst_port *port, int pbn,
4181 struct drm_dp_mst_topology_state *topology_state;
4182 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4183 int prev_slots, prev_bw, req_slots;
4185 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4186 if (IS_ERR(topology_state))
4187 return PTR_ERR(topology_state);
4189 /* Find the current allocation for this port, if any */
4190 list_for_each_entry(pos, &topology_state->vcpis, next) {
4191 if (pos->port == port) {
4193 prev_slots = vcpi->vcpi;
4194 prev_bw = vcpi->pbn;
4197 * This should never happen, unless the driver tries
4198 * releasing and allocating the same VCPI allocation,
4201 if (WARN_ON(!prev_slots)) {
4202 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4216 pbn_div = mgr->pbn_div;
4218 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4220 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4221 port->connector->base.id, port->connector->name,
4222 port, prev_slots, req_slots);
4223 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4224 port->connector->base.id, port->connector->name,
4225 port, prev_bw, pbn);
4227 /* Add the new allocation to the state */
4229 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4233 drm_dp_mst_get_port_malloc(port);
4235 list_add(&vcpi->next, &topology_state->vcpis);
4237 vcpi->vcpi = req_slots;
4242 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4245 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4246 * @state: global atomic state
4247 * @mgr: MST topology manager for the port
4248 * @port: The port to release the VCPI slots from
4250 * Releases any VCPI slots that have been allocated to a port in the atomic
4251 * state. Any atomic drivers which support MST must call this function in
4252 * their &drm_connector_helper_funcs.atomic_check() callback when the
4253 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4254 * removed) when it had VCPI allocated in the previous atomic state.
4256 * It is OK to call this even if @port has been removed from the system.
4257 * Additionally, it is OK to call this function multiple times on the same
4258 * @port as needed. It is not OK however, to call this function and
4259 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4263 * drm_dp_atomic_find_vcpi_slots()
4264 * drm_dp_mst_atomic_check()
4267 * 0 if all slots for this port were added back to
4268 * &drm_dp_mst_topology_state.avail_slots or negative error code
4270 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4271 struct drm_dp_mst_topology_mgr *mgr,
4272 struct drm_dp_mst_port *port)
4274 struct drm_dp_mst_topology_state *topology_state;
4275 struct drm_dp_vcpi_allocation *pos;
4278 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4279 if (IS_ERR(topology_state))
4280 return PTR_ERR(topology_state);
4282 list_for_each_entry(pos, &topology_state->vcpis, next) {
4283 if (pos->port == port) {
4288 if (WARN_ON(!found)) {
4289 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4290 port, &topology_state->base);
4294 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4296 drm_dp_mst_put_port_malloc(port);
4302 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4305 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4306 * @mgr: manager for this port
4307 * @port: port to allocate a virtual channel for.
4308 * @pbn: payload bandwidth number to request
4309 * @slots: returned number of slots for this PBN.
4311 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4312 struct drm_dp_mst_port *port, int pbn, int slots)
4316 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4323 if (port->vcpi.vcpi > 0) {
4324 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4325 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4326 if (pbn == port->vcpi.pbn) {
4327 drm_dp_mst_topology_put_port(port);
4332 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4334 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4335 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4338 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4339 pbn, port->vcpi.num_slots);
4341 /* Keep port allocated until its payload has been removed */
4342 drm_dp_mst_get_port_malloc(port);
4343 drm_dp_mst_topology_put_port(port);
4348 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4350 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4353 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4357 slots = port->vcpi.num_slots;
4358 drm_dp_mst_topology_put_port(port);
4361 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4364 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4365 * @mgr: manager for this port
4366 * @port: unverified pointer to a port.
4368 * This just resets the number of slots for the ports VCPI for later programming.
4370 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4373 * A port with VCPI will remain allocated until its VCPI is
4374 * released, no verified ref needed
4377 port->vcpi.num_slots = 0;
4379 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4382 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4383 * @mgr: manager for this port
4384 * @port: port to deallocate vcpi for
4386 * This can be called unconditionally, regardless of whether
4387 * drm_dp_mst_allocate_vcpi() succeeded or not.
4389 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4390 struct drm_dp_mst_port *port)
4392 if (!port->vcpi.vcpi)
4395 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4396 port->vcpi.num_slots = 0;
4398 port->vcpi.aligned_pbn = 0;
4399 port->vcpi.vcpi = 0;
4400 drm_dp_mst_put_port_malloc(port);
4402 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4404 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4405 int id, struct drm_dp_payload *payload)
4407 u8 payload_alloc[3], status;
4411 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4412 DP_PAYLOAD_TABLE_UPDATED);
4414 payload_alloc[0] = id;
4415 payload_alloc[1] = payload->start_slot;
4416 payload_alloc[2] = payload->num_slots;
4418 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4420 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
4425 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4427 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4431 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4434 usleep_range(10000, 20000);
4437 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
4448 * drm_dp_check_act_status() - Check ACT handled status.
4449 * @mgr: manager to use
4451 * Check the payload status bits in the DPCD for ACT handled completion.
4453 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4460 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4463 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4467 if (status & DP_PAYLOAD_ACT_HANDLED)
4472 } while (count < 30);
4474 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
4475 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
4483 EXPORT_SYMBOL(drm_dp_check_act_status);
4486 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4487 * @clock: dot clock for the mode
4488 * @bpp: bpp for the mode.
4489 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4491 * This uses the formula in the spec to calculate the PBN value for a mode.
4493 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4496 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4497 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4498 * common multiplier to render an integer PBN for all link rate/lane
4499 * counts combinations
4501 * peak_kbps *= (1006/1000)
4502 * peak_kbps *= (64/54)
4503 * peak_kbps *= 8 convert to bytes
4505 * If the bpp is in units of 1/16, further divide by 16. Put this
4506 * factor in the numerator rather than the denominator to avoid
4511 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4512 8 * 54 * 1000 * 1000);
4514 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4515 8 * 54 * 1000 * 1000);
4517 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4519 /* we want to kick the TX after we've ack the up/down IRQs. */
4520 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4522 queue_work(system_long_wq, &mgr->tx_work);
4525 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4526 struct drm_dp_mst_branch *mstb)
4528 struct drm_dp_mst_port *port;
4529 int tabs = mstb->lct;
4533 for (i = 0; i < tabs; i++)
4537 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
4538 list_for_each_entry(port, &mstb->ports, next) {
4539 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
4541 drm_dp_mst_dump_mstb(m, port->mstb);
4545 #define DP_PAYLOAD_TABLE_SIZE 64
4547 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4552 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4553 if (drm_dp_dpcd_read(mgr->aux,
4554 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4561 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4562 struct drm_dp_mst_port *port, char *name,
4565 struct edid *mst_edid;
4567 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4568 drm_edid_get_monitor_name(mst_edid, name, namelen);
4572 * drm_dp_mst_dump_topology(): dump topology to seq file.
4573 * @m: seq_file to dump output to
4574 * @mgr: manager to dump current topology for.
4576 * helper to dump MST topology to a seq file for debugfs.
4578 void drm_dp_mst_dump_topology(struct seq_file *m,
4579 struct drm_dp_mst_topology_mgr *mgr)
4582 struct drm_dp_mst_port *port;
4584 mutex_lock(&mgr->lock);
4585 if (mgr->mst_primary)
4586 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4589 mutex_unlock(&mgr->lock);
4591 mutex_lock(&mgr->payload_lock);
4592 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
4595 for (i = 0; i < mgr->max_payloads; i++) {
4596 if (mgr->proposed_vcpis[i]) {
4599 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4600 fetch_monitor_name(mgr, port, name, sizeof(name));
4601 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
4602 port->port_num, port->vcpi.vcpi,
4603 port->vcpi.num_slots,
4604 (*name != 0) ? name : "Unknown");
4606 seq_printf(m, "vcpi %d:unused\n", i);
4608 for (i = 0; i < mgr->max_payloads; i++) {
4609 seq_printf(m, "payload %d: %d, %d, %d\n",
4611 mgr->payloads[i].payload_state,
4612 mgr->payloads[i].start_slot,
4613 mgr->payloads[i].num_slots);
4617 mutex_unlock(&mgr->payload_lock);
4619 mutex_lock(&mgr->lock);
4620 if (mgr->mst_primary) {
4621 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4624 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4626 seq_printf(m, "dpcd read failed\n");
4629 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4631 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4633 seq_printf(m, "faux/mst read failed\n");
4636 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4638 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4640 seq_printf(m, "mst ctrl read failed\n");
4643 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4645 /* dump the standard OUI branch header */
4646 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4648 seq_printf(m, "branch oui read failed\n");
4651 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4653 for (i = 0x3; i < 0x8 && buf[i]; i++)
4654 seq_printf(m, "%c", buf[i]);
4655 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4656 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4657 if (dump_dp_payload_table(mgr, buf))
4658 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4662 mutex_unlock(&mgr->lock);
4665 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4667 static void drm_dp_tx_work(struct work_struct *work)
4669 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4671 mutex_lock(&mgr->qlock);
4672 if (!list_empty(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply)
4673 process_single_down_tx_qlock(mgr);
4674 mutex_unlock(&mgr->qlock);
4677 static inline void drm_dp_destroy_connector(struct drm_dp_mst_port *port)
4679 if (!port->connector)
4682 if (port->mgr->cbs->destroy_connector) {
4683 port->mgr->cbs->destroy_connector(port->mgr, port->connector);
4685 drm_connector_unregister(port->connector);
4686 drm_connector_put(port->connector);
4691 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4693 drm_dp_destroy_connector(port);
4695 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4696 drm_dp_mst_put_port_malloc(port);
4700 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4702 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4703 struct drm_dp_mst_port *port, *tmp;
4704 bool wake_tx = false;
4706 mutex_lock(&mgr->lock);
4707 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
4708 list_del(&port->next);
4709 drm_dp_mst_topology_put_port(port);
4711 mutex_unlock(&mgr->lock);
4713 /* drop any tx slots msg */
4714 mutex_lock(&mstb->mgr->qlock);
4715 if (mstb->tx_slots[0]) {
4716 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4717 mstb->tx_slots[0] = NULL;
4720 if (mstb->tx_slots[1]) {
4721 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4722 mstb->tx_slots[1] = NULL;
4725 mutex_unlock(&mstb->mgr->qlock);
4728 wake_up_all(&mstb->mgr->tx_waitq);
4730 drm_dp_mst_put_mstb_malloc(mstb);
4733 static void drm_dp_delayed_destroy_work(struct work_struct *work)
4735 struct drm_dp_mst_topology_mgr *mgr =
4736 container_of(work, struct drm_dp_mst_topology_mgr,
4737 delayed_destroy_work);
4738 bool send_hotplug = false, go_again;
4741 * Not a regular list traverse as we have to drop the destroy
4742 * connector lock before destroying the mstb/port, to avoid AB->BA
4743 * ordering between this lock and the config mutex.
4749 struct drm_dp_mst_branch *mstb;
4751 mutex_lock(&mgr->delayed_destroy_lock);
4752 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4753 struct drm_dp_mst_branch,
4756 list_del(&mstb->destroy_next);
4757 mutex_unlock(&mgr->delayed_destroy_lock);
4762 drm_dp_delayed_destroy_mstb(mstb);
4767 struct drm_dp_mst_port *port;
4769 mutex_lock(&mgr->delayed_destroy_lock);
4770 port = list_first_entry_or_null(&mgr->destroy_port_list,
4771 struct drm_dp_mst_port,
4774 list_del(&port->next);
4775 mutex_unlock(&mgr->delayed_destroy_lock);
4780 drm_dp_delayed_destroy_port(port);
4781 send_hotplug = true;
4787 drm_kms_helper_hotplug_event(mgr->dev);
4790 static struct drm_private_state *
4791 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
4793 struct drm_dp_mst_topology_state *state, *old_state =
4794 to_dp_mst_topology_state(obj->state);
4795 struct drm_dp_vcpi_allocation *pos, *vcpi;
4797 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
4801 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
4803 INIT_LIST_HEAD(&state->vcpis);
4805 list_for_each_entry(pos, &old_state->vcpis, next) {
4806 /* Prune leftover freed VCPI allocations */
4810 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
4814 drm_dp_mst_get_port_malloc(vcpi->port);
4815 list_add(&vcpi->next, &state->vcpis);
4818 return &state->base;
4821 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
4822 drm_dp_mst_put_port_malloc(pos->port);
4830 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
4831 struct drm_private_state *state)
4833 struct drm_dp_mst_topology_state *mst_state =
4834 to_dp_mst_topology_state(state);
4835 struct drm_dp_vcpi_allocation *pos, *tmp;
4837 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
4838 /* We only keep references to ports with non-zero VCPIs */
4840 drm_dp_mst_put_port_malloc(pos->port);
4847 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
4848 struct drm_dp_mst_branch *branch)
4850 while (port->parent) {
4851 if (port->parent == branch)
4854 if (port->parent->port_parent)
4855 port = port->parent->port_parent;
4863 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4864 struct drm_dp_mst_topology_state *state);
4867 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
4868 struct drm_dp_mst_topology_state *state)
4870 struct drm_dp_vcpi_allocation *vcpi;
4871 struct drm_dp_mst_port *port;
4872 int pbn_used = 0, ret;
4875 /* Check that we have at least one port in our state that's downstream
4876 * of this branch, otherwise we can skip this branch
4878 list_for_each_entry(vcpi, &state->vcpis, next) {
4880 !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
4889 if (mstb->port_parent)
4890 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
4891 mstb->port_parent->parent, mstb->port_parent,
4894 DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
4897 list_for_each_entry(port, &mstb->ports, next) {
4898 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
4909 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4910 struct drm_dp_mst_topology_state *state)
4912 struct drm_dp_vcpi_allocation *vcpi;
4915 if (port->pdt == DP_PEER_DEVICE_NONE)
4918 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
4921 list_for_each_entry(vcpi, &state->vcpis, next) {
4922 if (vcpi->port != port)
4933 /* This should never happen, as it means we tried to
4934 * set a mode before querying the full_pbn
4936 if (WARN_ON(!port->full_pbn))
4939 pbn_used = vcpi->pbn;
4941 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
4947 if (pbn_used > port->full_pbn) {
4948 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
4949 port->parent, port, pbn_used,
4954 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
4955 port->parent, port, pbn_used, port->full_pbn);
4961 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
4962 struct drm_dp_mst_topology_state *mst_state)
4964 struct drm_dp_vcpi_allocation *vcpi;
4965 int avail_slots = 63, payload_count = 0;
4967 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4968 /* Releasing VCPI is always OK-even if the port is gone */
4970 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4975 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4976 vcpi->port, vcpi->vcpi);
4978 avail_slots -= vcpi->vcpi;
4979 if (avail_slots < 0) {
4980 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4981 vcpi->port, mst_state,
4982 avail_slots + vcpi->vcpi);
4986 if (++payload_count > mgr->max_payloads) {
4987 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4988 mgr, mst_state, mgr->max_payloads);
4992 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4993 mgr, mst_state, avail_slots,
5000 * drm_dp_mst_add_affected_dsc_crtcs
5001 * @state: Pointer to the new struct drm_dp_mst_topology_state
5002 * @mgr: MST topology manager
5004 * Whenever there is a change in mst topology
5005 * DSC configuration would have to be recalculated
5006 * therefore we need to trigger modeset on all affected
5007 * CRTCs in that topology
5010 * drm_dp_mst_atomic_enable_dsc()
5012 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5014 struct drm_dp_mst_topology_state *mst_state;
5015 struct drm_dp_vcpi_allocation *pos;
5016 struct drm_connector *connector;
5017 struct drm_connector_state *conn_state;
5018 struct drm_crtc *crtc;
5019 struct drm_crtc_state *crtc_state;
5021 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5023 if (IS_ERR(mst_state))
5026 list_for_each_entry(pos, &mst_state->vcpis, next) {
5028 connector = pos->port->connector;
5033 conn_state = drm_atomic_get_connector_state(state, connector);
5035 if (IS_ERR(conn_state))
5036 return PTR_ERR(conn_state);
5038 crtc = conn_state->crtc;
5043 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5046 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5048 if (IS_ERR(crtc_state))
5049 return PTR_ERR(crtc_state);
5051 DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5054 crtc_state->mode_changed = true;
5058 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5061 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5062 * @state: Pointer to the new drm_atomic_state
5063 * @port: Pointer to the affected MST Port
5064 * @pbn: Newly recalculated bw required for link with DSC enabled
5065 * @pbn_div: Divider to calculate correct number of pbn per slot
5066 * @enable: Boolean flag to enable or disable DSC on the port
5068 * This function enables DSC on the given Port
5069 * by recalculating its vcpi from pbn provided
5070 * and sets dsc_enable flag to keep track of which
5071 * ports have DSC enabled
5074 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5075 struct drm_dp_mst_port *port,
5076 int pbn, int pbn_div,
5079 struct drm_dp_mst_topology_state *mst_state;
5080 struct drm_dp_vcpi_allocation *pos;
5084 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5086 if (IS_ERR(mst_state))
5087 return PTR_ERR(mst_state);
5089 list_for_each_entry(pos, &mst_state->vcpis, next) {
5090 if (pos->port == port) {
5097 DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5102 if (pos->dsc_enabled == enable) {
5103 DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5104 port, enable, pos->vcpi);
5109 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5110 DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5116 pos->dsc_enabled = enable;
5120 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5122 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5123 * atomic update is valid
5124 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5126 * Checks the given topology state for an atomic update to ensure that it's
5127 * valid. This includes checking whether there's enough bandwidth to support
5128 * the new VCPI allocations in the atomic update.
5130 * Any atomic drivers supporting DP MST must make sure to call this after
5131 * checking the rest of their state in their
5132 * &drm_mode_config_funcs.atomic_check() callback.
5135 * drm_dp_atomic_find_vcpi_slots()
5136 * drm_dp_atomic_release_vcpi_slots()
5140 * 0 if the new state is valid, negative error code otherwise.
5142 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5144 struct drm_dp_mst_topology_mgr *mgr;
5145 struct drm_dp_mst_topology_state *mst_state;
5148 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5149 if (!mgr->mst_state)
5152 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5156 mutex_lock(&mgr->lock);
5157 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5159 mutex_unlock(&mgr->lock);
5168 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5170 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5171 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5172 .atomic_destroy_state = drm_dp_mst_destroy_state,
5174 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5177 * drm_atomic_get_mst_topology_state: get MST topology state
5179 * @state: global atomic state
5180 * @mgr: MST topology manager, also the private object in this case
5182 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5183 * state vtable so that the private object state returned is that of a MST
5184 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5185 * to care of the locking, so warn if don't hold the connection_mutex.
5189 * The MST topology state or error pointer.
5191 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5192 struct drm_dp_mst_topology_mgr *mgr)
5194 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5196 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5199 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5200 * @mgr: manager struct to initialise
5201 * @dev: device providing this structure - for i2c addition.
5202 * @aux: DP helper aux channel to talk to this device
5203 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5204 * @max_payloads: maximum number of payloads this GPU can source
5205 * @conn_base_id: the connector object ID the MST device is connected to.
5207 * Return 0 for success, or negative error code on failure
5209 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5210 struct drm_device *dev, struct drm_dp_aux *aux,
5211 int max_dpcd_transaction_bytes,
5212 int max_payloads, int conn_base_id)
5214 struct drm_dp_mst_topology_state *mst_state;
5216 mutex_init(&mgr->lock);
5217 mutex_init(&mgr->qlock);
5218 mutex_init(&mgr->payload_lock);
5219 mutex_init(&mgr->delayed_destroy_lock);
5220 mutex_init(&mgr->up_req_lock);
5221 mutex_init(&mgr->probe_lock);
5222 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5223 mutex_init(&mgr->topology_ref_history_lock);
5225 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5226 INIT_LIST_HEAD(&mgr->destroy_port_list);
5227 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5228 INIT_LIST_HEAD(&mgr->up_req_list);
5229 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5230 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5231 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5232 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5233 init_waitqueue_head(&mgr->tx_waitq);
5236 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5237 mgr->max_payloads = max_payloads;
5238 mgr->conn_base_id = conn_base_id;
5239 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5240 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5242 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5245 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5246 if (!mgr->proposed_vcpis)
5248 set_bit(0, &mgr->payload_mask);
5250 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5251 if (mst_state == NULL)
5254 mst_state->mgr = mgr;
5255 INIT_LIST_HEAD(&mst_state->vcpis);
5257 drm_atomic_private_obj_init(dev, &mgr->base,
5259 &drm_dp_mst_topology_state_funcs);
5263 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5266 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5267 * @mgr: manager to destroy
5269 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5271 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5272 flush_work(&mgr->work);
5273 cancel_work_sync(&mgr->delayed_destroy_work);
5274 mutex_lock(&mgr->payload_lock);
5275 kfree(mgr->payloads);
5276 mgr->payloads = NULL;
5277 kfree(mgr->proposed_vcpis);
5278 mgr->proposed_vcpis = NULL;
5279 mutex_unlock(&mgr->payload_lock);
5282 drm_atomic_private_obj_fini(&mgr->base);
5285 mutex_destroy(&mgr->delayed_destroy_lock);
5286 mutex_destroy(&mgr->payload_lock);
5287 mutex_destroy(&mgr->qlock);
5288 mutex_destroy(&mgr->lock);
5289 mutex_destroy(&mgr->up_req_lock);
5290 mutex_destroy(&mgr->probe_lock);
5291 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5292 mutex_destroy(&mgr->topology_ref_history_lock);
5295 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5297 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5301 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5304 for (i = 0; i < num - 1; i++) {
5305 if (msgs[i].flags & I2C_M_RD ||
5310 return msgs[num - 1].flags & I2C_M_RD &&
5311 msgs[num - 1].len <= 0xff;
5315 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
5318 struct drm_dp_aux *aux = adapter->algo_data;
5319 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
5320 struct drm_dp_mst_branch *mstb;
5321 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5323 struct drm_dp_sideband_msg_req_body msg;
5324 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5327 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5331 if (!remote_i2c_read_ok(msgs, num)) {
5332 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
5337 memset(&msg, 0, sizeof(msg));
5338 msg.req_type = DP_REMOTE_I2C_READ;
5339 msg.u.i2c_read.num_transactions = num - 1;
5340 msg.u.i2c_read.port_number = port->port_num;
5341 for (i = 0; i < num - 1; i++) {
5342 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5343 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5344 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5345 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5347 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5348 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5350 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5357 drm_dp_encode_sideband_req(&msg, txmsg);
5359 drm_dp_queue_down_tx(mgr, txmsg);
5361 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5364 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5368 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5372 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5377 drm_dp_mst_topology_put_mstb(mstb);
5381 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5383 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5384 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5385 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5386 I2C_FUNC_10BIT_ADDR;
5389 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5390 .functionality = drm_dp_mst_i2c_functionality,
5391 .master_xfer = drm_dp_mst_i2c_xfer,
5395 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5396 * @aux: DisplayPort AUX channel
5398 * Returns 0 on success or a negative error code on failure.
5400 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
5402 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5403 aux->ddc.algo_data = aux;
5404 aux->ddc.retries = 3;
5406 aux->ddc.class = I2C_CLASS_DDC;
5407 aux->ddc.owner = THIS_MODULE;
5408 aux->ddc.dev.parent = aux->dev;
5409 aux->ddc.dev.of_node = aux->dev->of_node;
5411 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
5412 sizeof(aux->ddc.name));
5414 return i2c_add_adapter(&aux->ddc);
5418 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5419 * @aux: DisplayPort AUX channel
5421 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
5423 i2c_del_adapter(&aux->ddc);
5427 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5428 * @port: The port to check
5430 * A single physical MST hub object can be represented in the topology
5431 * by multiple branches, with virtual ports between those branches.
5433 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5434 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5435 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5437 * May acquire mgr->lock
5440 * true if the port is a virtual DP peer device, false otherwise
5442 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5444 struct drm_dp_mst_port *downstream_port;
5446 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5449 /* Virtual DP Sink (Internal Display Panel) */
5450 if (port->port_num >= 8)
5453 /* DP-to-HDMI Protocol Converter */
5454 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5460 mutex_lock(&port->mgr->lock);
5461 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5463 port->mstb->num_ports == 2) {
5464 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5465 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5466 !downstream_port->input) {
5467 mutex_unlock(&port->mgr->lock);
5472 mutex_unlock(&port->mgr->lock);
5478 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5479 * @port: The port to check. A leaf of the MST tree with an attached display.
5481 * Depending on the situation, DSC may be enabled via the endpoint aux,
5482 * the immediately upstream aux, or the connector's physical aux.
5484 * This is both the correct aux to read DSC_CAPABILITY and the
5485 * correct aux to write DSC_ENABLED.
5487 * This operation can be expensive (up to four aux reads), so
5488 * the caller should cache the return.
5491 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5493 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5495 struct drm_dp_mst_port *immediate_upstream_port;
5496 struct drm_dp_mst_port *fec_port;
5497 struct drm_dp_desc desc = { 0 };
5504 if (port->parent->port_parent)
5505 immediate_upstream_port = port->parent->port_parent;
5507 immediate_upstream_port = NULL;
5509 fec_port = immediate_upstream_port;
5512 * Each physical link (i.e. not a virtual port) between the
5513 * output and the primary device must support FEC
5515 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5516 !fec_port->fec_capable)
5519 fec_port = fec_port->parent->port_parent;
5522 /* DP-to-DP peer device */
5523 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5526 if (drm_dp_dpcd_read(&port->aux,
5527 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5529 if (drm_dp_dpcd_read(&port->aux,
5530 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5532 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5533 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5536 /* Enpoint decompression with DP-to-DP peer device */
5537 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5538 (endpoint_fec & DP_FEC_CAPABLE) &&
5539 (upstream_dsc & 0x2) /* DSC passthrough */)
5542 /* Virtual DPCD decompression with DP-to-DP peer device */
5543 return &immediate_upstream_port->aux;
5546 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5547 if (drm_dp_mst_is_virtual_dpcd(port))
5552 * Applies to ports for which:
5553 * - Physical aux has Synaptics OUI
5554 * - DPv1.4 or higher
5555 * - Port is on primary branch device
5556 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5558 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5561 if (drm_dp_has_quirk(&desc, 0,
5562 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5563 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5564 port->parent == port->mgr->mst_primary) {
5567 if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
5568 &downstreamport, 1) < 0)
5571 if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
5572 ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
5573 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5574 return port->mgr->aux;
5578 * The check below verifies if the MST sink
5579 * connected to the GPU is capable of DSC -
5580 * therefore the endpoint needs to be
5581 * both DSC and FEC capable.
5583 if (drm_dp_dpcd_read(&port->aux,
5584 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5586 if (drm_dp_dpcd_read(&port->aux,
5587 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5589 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5590 (endpoint_fec & DP_FEC_CAPABLE))
5595 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);