2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
48 #define DRM_TIMESTAMP_MAXRETRIES 3
50 /* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
53 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
56 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
57 struct timeval *tvblank, bool in_vblank_irq);
59 static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
62 * Default to use monotonic timestamps for wait-for-vblank and page-flip
65 unsigned int drm_timestamp_monotonic = 1;
67 static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
69 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
70 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
71 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
72 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
73 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
74 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
76 static void store_vblank(struct drm_device *dev, unsigned int pipe,
78 struct timeval *t_vblank, u32 last)
80 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
82 assert_spin_locked(&dev->vblank_time_lock);
86 write_seqlock(&vblank->seqlock);
87 vblank->time = *t_vblank;
88 vblank->count += vblank_count_inc;
89 write_sequnlock(&vblank->seqlock);
93 * "No hw counter" fallback implementation of .get_vblank_counter() hook,
94 * if there is no useable hardware frame counter available.
96 static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
98 WARN_ON_ONCE(dev->max_vblank_count != 0);
102 static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
104 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
105 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
107 if (crtc->funcs->get_vblank_counter)
108 return crtc->funcs->get_vblank_counter(crtc);
111 if (dev->driver->get_vblank_counter)
112 return dev->driver->get_vblank_counter(dev, pipe);
114 return drm_vblank_no_hw_counter(dev, pipe);
118 * Reset the stored timestamp for the current vblank count to correspond
119 * to the last vblank occurred.
121 * Only to be called from drm_crtc_vblank_on().
123 * Note: caller must hold &drm_device.vbl_lock since this reads & writes
124 * device vblank fields.
126 static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
130 struct timeval t_vblank;
131 int count = DRM_TIMESTAMP_MAXRETRIES;
133 spin_lock(&dev->vblank_time_lock);
136 * sample the current counter to avoid random jumps
137 * when drm_vblank_enable() applies the diff
140 cur_vblank = __get_vblank_counter(dev, pipe);
141 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, false);
142 } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
145 * Only reinitialize corresponding vblank timestamp if high-precision query
146 * available and didn't fail. Otherwise reinitialize delayed at next vblank
147 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
150 t_vblank = (struct timeval) {0, 0};
153 * +1 to make sure user will never see the same
154 * vblank counter value before and after a modeset
156 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
158 spin_unlock(&dev->vblank_time_lock);
162 * Call back into the driver to update the appropriate vblank counter
163 * (specified by @pipe). Deal with wraparound, if it occurred, and
164 * update the last read value so we can deal with wraparound on the next
167 * Only necessary when going from off->on, to account for frames we
168 * didn't get an interrupt for.
170 * Note: caller must hold &drm_device.vbl_lock since this reads & writes
171 * device vblank fields.
173 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
176 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
177 u32 cur_vblank, diff;
179 struct timeval t_vblank;
180 int count = DRM_TIMESTAMP_MAXRETRIES;
181 int framedur_ns = vblank->framedur_ns;
184 * Interrupts were disabled prior to this call, so deal with counter
186 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
187 * here if the register is small or we had vblank interrupts off for
190 * We repeat the hardware vblank counter & timestamp query until
191 * we get consistent results. This to prevent races between gpu
192 * updating its hardware counter while we are retrieving the
193 * corresponding vblank timestamp.
196 cur_vblank = __get_vblank_counter(dev, pipe);
197 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, in_vblank_irq);
198 } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
200 if (dev->max_vblank_count != 0) {
201 /* trust the hw counter when it's around */
202 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
203 } else if (rc && framedur_ns) {
204 const struct timeval *t_old;
207 t_old = &vblank->time;
208 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
211 * Figure out how many vblanks we've missed based
212 * on the difference in the timestamps and the
213 * frame/field duration.
215 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
217 if (diff == 0 && in_vblank_irq)
218 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
219 " diff_ns = %lld, framedur_ns = %d)\n",
220 pipe, (long long) diff_ns, framedur_ns);
222 /* some kind of default for drivers w/o accurate vbl timestamping */
223 diff = in_vblank_irq ? 1 : 0;
227 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
228 * interval? If so then vblank irqs keep running and it will likely
229 * happen that the hardware vblank counter is not trustworthy as it
230 * might reset at some point in that interval and vblank timestamps
231 * are not trustworthy either in that interval. Iow. this can result
232 * in a bogus diff >> 1 which must be avoided as it would cause
233 * random large forward jumps of the software vblank counter.
235 if (diff > 1 && (vblank->inmodeset & 0x2)) {
236 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
237 " due to pre-modeset.\n", pipe, diff);
241 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
242 " current=%u, diff=%u, hw=%u hw_last=%u\n",
243 pipe, vblank->count, diff, cur_vblank, vblank->last);
246 WARN_ON_ONCE(cur_vblank != vblank->last);
251 * Only reinitialize corresponding vblank timestamp if high-precision query
252 * available and didn't fail, or we were called from the vblank interrupt.
253 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
254 * for now, to mark the vblanktimestamp as invalid.
256 if (!rc && in_vblank_irq)
257 t_vblank = (struct timeval) {0, 0};
259 store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
262 static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
264 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
266 if (WARN_ON(pipe >= dev->num_crtcs))
269 return vblank->count;
273 * drm_accurate_vblank_count - retrieve the master vblank counter
274 * @crtc: which counter to retrieve
276 * This function is similar to @drm_crtc_vblank_count but this
277 * function interpolates to handle a race with vblank irq's.
279 * This is mostly useful for hardware that can obtain the scanout
280 * position, but doesn't have a frame counter.
282 u32 drm_accurate_vblank_count(struct drm_crtc *crtc)
284 struct drm_device *dev = crtc->dev;
285 unsigned int pipe = drm_crtc_index(crtc);
289 WARN(!dev->driver->get_vblank_timestamp,
290 "This function requires support for accurate vblank timestamps.");
292 spin_lock_irqsave(&dev->vblank_time_lock, flags);
294 drm_update_vblank_count(dev, pipe, false);
295 vblank = drm_vblank_count(dev, pipe);
297 spin_unlock_irqrestore(&dev->vblank_time_lock, flags);
301 EXPORT_SYMBOL(drm_accurate_vblank_count);
303 static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
305 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
306 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
308 if (crtc->funcs->disable_vblank) {
309 crtc->funcs->disable_vblank(crtc);
314 dev->driver->disable_vblank(dev, pipe);
318 * Disable vblank irq's on crtc, make sure that last vblank count
319 * of hardware and corresponding consistent software vblank counter
320 * are preserved, even if there are any spurious vblank irq's after
323 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
325 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
326 unsigned long irqflags;
328 assert_spin_locked(&dev->vbl_lock);
330 /* Prevent vblank irq processing while disabling vblank irqs,
331 * so no updates of timestamps or count can happen after we've
332 * disabled. Needed to prevent races in case of delayed irq's.
334 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
337 * Only disable vblank interrupts if they're enabled. This avoids
338 * calling the ->disable_vblank() operation in atomic context with the
339 * hardware potentially runtime suspended.
341 if (vblank->enabled) {
342 __disable_vblank(dev, pipe);
343 vblank->enabled = false;
347 * Always update the count and timestamp to maintain the
348 * appearance that the counter has been ticking all along until
349 * this time. This makes the count account for the entire time
350 * between drm_crtc_vblank_on() and drm_crtc_vblank_off().
352 drm_update_vblank_count(dev, pipe, false);
354 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
357 static void vblank_disable_fn(unsigned long arg)
359 struct drm_vblank_crtc *vblank = (void *)arg;
360 struct drm_device *dev = vblank->dev;
361 unsigned int pipe = vblank->pipe;
362 unsigned long irqflags;
364 spin_lock_irqsave(&dev->vbl_lock, irqflags);
365 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
366 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
367 vblank_disable_and_save(dev, pipe);
369 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
373 * drm_vblank_cleanup - cleanup vblank support
376 * This function cleans up any resources allocated in drm_vblank_init.
378 void drm_vblank_cleanup(struct drm_device *dev)
382 /* Bail if the driver didn't call drm_vblank_init() */
383 if (dev->num_crtcs == 0)
386 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
387 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
389 WARN_ON(READ_ONCE(vblank->enabled) &&
390 drm_core_check_feature(dev, DRIVER_MODESET));
392 del_timer_sync(&vblank->disable_timer);
399 EXPORT_SYMBOL(drm_vblank_cleanup);
402 * drm_vblank_init - initialize vblank support
404 * @num_crtcs: number of CRTCs supported by @dev
406 * This function initializes vblank support for @num_crtcs display pipelines.
409 * Zero on success or a negative error code on failure.
411 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
416 spin_lock_init(&dev->vbl_lock);
417 spin_lock_init(&dev->vblank_time_lock);
419 dev->num_crtcs = num_crtcs;
421 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
425 for (i = 0; i < num_crtcs; i++) {
426 struct drm_vblank_crtc *vblank = &dev->vblank[i];
430 init_waitqueue_head(&vblank->queue);
431 setup_timer(&vblank->disable_timer, vblank_disable_fn,
432 (unsigned long)vblank);
433 seqlock_init(&vblank->seqlock);
436 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
438 /* Driver specific high-precision vblank timestamping supported? */
439 if (dev->driver->get_vblank_timestamp)
440 DRM_INFO("Driver supports precise vblank timestamp query.\n");
442 DRM_INFO("No driver support for vblank timestamp query.\n");
444 /* Must have precise timestamping for reliable vblank instant disable */
445 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
446 dev->vblank_disable_immediate = false;
447 DRM_INFO("Setting vblank_disable_immediate to false because "
448 "get_vblank_timestamp == NULL\n");
457 EXPORT_SYMBOL(drm_vblank_init);
460 * drm_irq_install - install IRQ handler
462 * @irq: IRQ number to install the handler for
464 * Initializes the IRQ related data. Installs the handler, calling the driver
465 * irq_preinstall() and irq_postinstall() functions before and after the
468 * This is the simplified helper interface provided for drivers with no special
469 * needs. Drivers which need to install interrupt handlers for multiple
470 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
471 * that vblank interrupts are available.
474 * Zero on success or a negative error code on failure.
476 int drm_irq_install(struct drm_device *dev, int irq)
479 unsigned long sh_flags = 0;
481 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
487 /* Driver must have been initialized */
488 if (!dev->dev_private)
491 if (dev->irq_enabled)
493 dev->irq_enabled = true;
495 DRM_DEBUG("irq=%d\n", irq);
497 /* Before installing handler */
498 if (dev->driver->irq_preinstall)
499 dev->driver->irq_preinstall(dev);
501 /* Install handler */
502 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
503 sh_flags = IRQF_SHARED;
505 ret = request_irq(irq, dev->driver->irq_handler,
506 sh_flags, dev->driver->name, dev);
509 dev->irq_enabled = false;
513 /* After installing handler */
514 if (dev->driver->irq_postinstall)
515 ret = dev->driver->irq_postinstall(dev);
518 dev->irq_enabled = false;
519 if (drm_core_check_feature(dev, DRIVER_LEGACY))
520 vga_client_register(dev->pdev, NULL, NULL, NULL);
528 EXPORT_SYMBOL(drm_irq_install);
531 * drm_irq_uninstall - uninstall the IRQ handler
534 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
535 * This should only be called by drivers which used drm_irq_install() to set up
536 * their interrupt handler. Other drivers must only reset
537 * &drm_device.irq_enabled to false.
539 * Note that for kernel modesetting drivers it is a bug if this function fails.
540 * The sanity checks are only to catch buggy user modesetting drivers which call
541 * the same function through an ioctl.
544 * Zero on success or a negative error code on failure.
546 int drm_irq_uninstall(struct drm_device *dev)
548 unsigned long irqflags;
552 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
555 irq_enabled = dev->irq_enabled;
556 dev->irq_enabled = false;
559 * Wake up any waiters so they don't hang. This is just to paper over
560 * issues for UMS drivers which aren't in full control of their
561 * vblank/irq handling. KMS drivers must ensure that vblanks are all
562 * disabled when uninstalling the irq handler.
564 if (dev->num_crtcs) {
565 spin_lock_irqsave(&dev->vbl_lock, irqflags);
566 for (i = 0; i < dev->num_crtcs; i++) {
567 struct drm_vblank_crtc *vblank = &dev->vblank[i];
569 if (!vblank->enabled)
572 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
574 vblank_disable_and_save(dev, i);
575 wake_up(&vblank->queue);
577 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
583 DRM_DEBUG("irq=%d\n", dev->irq);
585 if (drm_core_check_feature(dev, DRIVER_LEGACY))
586 vga_client_register(dev->pdev, NULL, NULL, NULL);
588 if (dev->driver->irq_uninstall)
589 dev->driver->irq_uninstall(dev);
591 free_irq(dev->irq, dev);
595 EXPORT_SYMBOL(drm_irq_uninstall);
597 int drm_legacy_irq_control(struct drm_device *dev, void *data,
598 struct drm_file *file_priv)
600 struct drm_control *ctl = data;
603 /* if we haven't irq we fallback for compatibility reasons -
604 * this used to be a separate function in drm_dma.h
607 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
609 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
611 /* UMS was only ever supported on pci devices. */
612 if (WARN_ON(!dev->pdev))
616 case DRM_INST_HANDLER:
617 irq = dev->pdev->irq;
619 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
622 mutex_lock(&dev->struct_mutex);
623 ret = drm_irq_install(dev, irq);
624 mutex_unlock(&dev->struct_mutex);
627 case DRM_UNINST_HANDLER:
628 mutex_lock(&dev->struct_mutex);
629 ret = drm_irq_uninstall(dev);
630 mutex_unlock(&dev->struct_mutex);
639 * drm_calc_timestamping_constants - calculate vblank timestamp constants
640 * @crtc: drm_crtc whose timestamp constants should be updated.
641 * @mode: display mode containing the scanout timings
643 * Calculate and store various constants which are later
644 * needed by vblank and swap-completion timestamping, e.g,
645 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
646 * derived from CRTC's true scanout timing, so they take
647 * things like panel scaling or other adjustments into account.
649 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
650 const struct drm_display_mode *mode)
652 struct drm_device *dev = crtc->dev;
653 unsigned int pipe = drm_crtc_index(crtc);
654 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
655 int linedur_ns = 0, framedur_ns = 0;
656 int dotclock = mode->crtc_clock;
661 if (WARN_ON(pipe >= dev->num_crtcs))
664 /* Valid dotclock? */
666 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
669 * Convert scanline length in pixels and video
670 * dot clock to line duration and frame duration
673 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
674 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
677 * Fields of interlaced scanout modes are only half a frame duration.
679 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
682 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
685 vblank->linedur_ns = linedur_ns;
686 vblank->framedur_ns = framedur_ns;
687 vblank->hwmode = *mode;
689 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
690 crtc->base.id, mode->crtc_htotal,
691 mode->crtc_vtotal, mode->crtc_vdisplay);
692 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
693 crtc->base.id, dotclock, framedur_ns, linedur_ns);
695 EXPORT_SYMBOL(drm_calc_timestamping_constants);
698 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
700 * @pipe: index of CRTC whose vblank timestamp to retrieve
701 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
702 * On return contains true maximum error of timestamp
703 * @vblank_time: Pointer to struct timeval which should receive the timestamp
705 * True when called from drm_crtc_handle_vblank(). Some drivers
706 * need to apply some workarounds for gpu-specific vblank irq quirks
709 * Implements calculation of exact vblank timestamps from given drm_display_mode
710 * timings and current video scanout position of a CRTC. This can be called from
711 * within get_vblank_timestamp() implementation of a kms driver to implement the
712 * actual timestamping.
714 * Should return timestamps conforming to the OML_sync_control OpenML
715 * extension specification. The timestamp corresponds to the end of
716 * the vblank interval, aka start of scanout of topmost-leftmost display
717 * pixel in the following video frame.
719 * Requires support for optional dev->driver->get_scanout_position()
720 * in kms driver, plus a bit of setup code to provide a drm_display_mode
721 * that corresponds to the true scanout timing.
723 * The current implementation only handles standard video modes. It
724 * returns as no operation if a doublescan or interlaced video mode is
725 * active. Higher level code is expected to handle this.
727 * This function can be used to implement the &drm_driver.get_vblank_timestamp
728 * directly, if the driver implements the &drm_driver.get_scanout_position hook.
730 * Note that atomic drivers must call drm_calc_timestamping_constants() before
731 * enabling a CRTC. The atomic helpers already take care of that in
732 * drm_atomic_helper_update_legacy_modeset_state().
736 * Returns true on success, and false on failure, i.e. when no accurate
737 * timestamp could be acquired.
739 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
742 struct timeval *vblank_time,
745 struct timeval tv_etime;
746 ktime_t stime, etime;
748 struct drm_crtc *crtc;
749 const struct drm_display_mode *mode;
750 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
752 int delta_ns, duration_ns;
754 if (!drm_core_check_feature(dev, DRIVER_MODESET))
757 crtc = drm_crtc_from_index(dev, pipe);
759 if (pipe >= dev->num_crtcs || !crtc) {
760 DRM_ERROR("Invalid crtc %u\n", pipe);
764 /* Scanout position query not supported? Should not happen. */
765 if (!dev->driver->get_scanout_position) {
766 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
770 if (drm_drv_uses_atomic_modeset(dev))
771 mode = &vblank->hwmode;
773 mode = &crtc->hwmode;
775 /* If mode timing undefined, just return as no-op:
776 * Happens during initial modesetting of a crtc.
778 if (mode->crtc_clock == 0) {
779 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
783 /* Get current scanout position with system timestamp.
784 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
785 * if single query takes longer than max_error nanoseconds.
787 * This guarantees a tight bound on maximum error if
788 * code gets preempted or delayed for some reason.
790 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
792 * Get vertical and horizontal scanout position vpos, hpos,
793 * and bounding timestamps stime, etime, pre/post query.
795 vbl_status = dev->driver->get_scanout_position(dev, pipe,
801 /* Return as no-op if scanout query unsupported or failed. */
803 DRM_DEBUG("crtc %u : scanoutpos query failed.\n",
808 /* Compute uncertainty in timestamp of scanout position query. */
809 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
811 /* Accept result with < max_error nsecs timing uncertainty. */
812 if (duration_ns <= *max_error)
816 /* Noisy system timing? */
817 if (i == DRM_TIMESTAMP_MAXRETRIES) {
818 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
819 pipe, duration_ns/1000, *max_error/1000, i);
822 /* Return upper bound of timestamp precision error. */
823 *max_error = duration_ns;
825 /* Convert scanout position into elapsed time at raw_time query
826 * since start of scanout at first display scanline. delta_ns
827 * can be negative if start of scanout hasn't happened yet.
829 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
832 if (!drm_timestamp_monotonic)
833 etime = ktime_mono_to_real(etime);
835 /* save this only for debugging purposes */
836 tv_etime = ktime_to_timeval(etime);
837 /* Subtract time delta from raw timestamp to get final
838 * vblank_time timestamp for end of vblank.
840 etime = ktime_sub_ns(etime, delta_ns);
841 *vblank_time = ktime_to_timeval(etime);
843 DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
845 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
846 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
847 duration_ns/1000, i);
851 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
853 static struct timeval get_drm_timestamp(void)
857 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
858 return ktime_to_timeval(now);
862 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
865 * @pipe: index of CRTC whose vblank timestamp to retrieve
866 * @tvblank: Pointer to target struct timeval which should receive the timestamp
868 * True when called from drm_crtc_handle_vblank(). Some drivers
869 * need to apply some workarounds for gpu-specific vblank irq quirks
872 * Fetches the system timestamp corresponding to the time of the most recent
873 * vblank interval on specified CRTC. May call into kms-driver to
874 * compute the timestamp with a high-precision GPU specific method.
876 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
877 * call, i.e., it isn't very precisely locked to the true vblank.
880 * True if timestamp is considered to be very precise, false otherwise.
883 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
884 struct timeval *tvblank, bool in_vblank_irq)
888 /* Define requested maximum error on timestamps (nanoseconds). */
889 int max_error = (int) drm_timestamp_precision * 1000;
891 /* Query driver if possible and precision timestamping enabled. */
892 if (dev->driver->get_vblank_timestamp && (max_error > 0))
893 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
894 tvblank, in_vblank_irq);
896 /* GPU high precision timestamp query unsupported or failed.
897 * Return current monotonic/gettimeofday timestamp as best estimate.
900 *tvblank = get_drm_timestamp();
906 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
907 * @crtc: which counter to retrieve
909 * Fetches the "cooked" vblank count value that represents the number of
910 * vblank events since the system was booted, including lost events due to
911 * modesetting activity.
914 * The software vblank counter.
916 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
918 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
920 EXPORT_SYMBOL(drm_crtc_vblank_count);
923 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
924 * system timestamp corresponding to that vblank counter value.
926 * @pipe: index of CRTC whose counter to retrieve
927 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
929 * Fetches the "cooked" vblank count value that represents the number of
930 * vblank events since the system was booted, including lost events due to
931 * modesetting activity. Returns corresponding system timestamp of the time
932 * of the vblank interval that corresponds to the current vblank counter value.
934 * This is the legacy version of drm_crtc_vblank_count_and_time().
936 static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
937 struct timeval *vblanktime)
939 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
943 if (WARN_ON(pipe >= dev->num_crtcs)) {
944 *vblanktime = (struct timeval) { 0 };
949 seq = read_seqbegin(&vblank->seqlock);
950 vblank_count = vblank->count;
951 *vblanktime = vblank->time;
952 } while (read_seqretry(&vblank->seqlock, seq));
958 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
959 * and the system timestamp corresponding to that vblank counter value
960 * @crtc: which counter to retrieve
961 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
963 * Fetches the "cooked" vblank count value that represents the number of
964 * vblank events since the system was booted, including lost events due to
965 * modesetting activity. Returns corresponding system timestamp of the time
966 * of the vblank interval that corresponds to the current vblank counter value.
968 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
969 struct timeval *vblanktime)
971 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
974 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
976 static void send_vblank_event(struct drm_device *dev,
977 struct drm_pending_vblank_event *e,
978 unsigned long seq, struct timeval *now)
980 e->event.sequence = seq;
981 e->event.tv_sec = now->tv_sec;
982 e->event.tv_usec = now->tv_usec;
984 trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe,
987 drm_send_event_locked(dev, &e->base);
991 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
992 * @crtc: the source CRTC of the vblank event
993 * @e: the event to send
995 * A lot of drivers need to generate vblank events for the very next vblank
996 * interrupt. For example when the page flip interrupt happens when the page
997 * flip gets armed, but not when it actually executes within the next vblank
998 * period. This helper function implements exactly the required vblank arming
1001 * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an
1002 * atomic commit must ensure that the next vblank happens at exactly the same
1003 * time as the atomic commit is committed to the hardware. This function itself
1004 * does **not** protect again the next vblank interrupt racing with either this
1005 * function call or the atomic commit operation. A possible sequence could be:
1007 * 1. Driver commits new hardware state into vblank-synchronized registers.
1008 * 2. A vblank happens, committing the hardware state. Also the corresponding
1009 * vblank interrupt is fired off and fully processed by the interrupt
1011 * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
1012 * 4. The event is only send out for the next vblank, which is wrong.
1014 * An equivalent race can happen when the driver calls
1015 * drm_crtc_arm_vblank_event() before writing out the new hardware state.
1017 * The only way to make this work safely is to prevent the vblank from firing
1018 * (and the hardware from committing anything else) until the entire atomic
1019 * commit sequence has run to completion. If the hardware does not have such a
1020 * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
1021 * Instead drivers need to manually send out the event from their interrupt
1022 * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
1023 * possible race with the hardware committing the atomic update.
1025 * Caller must hold event lock. Caller must also hold a vblank reference for
1026 * the event @e, which will be dropped when the next vblank arrives.
1028 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
1029 struct drm_pending_vblank_event *e)
1031 struct drm_device *dev = crtc->dev;
1032 unsigned int pipe = drm_crtc_index(crtc);
1034 assert_spin_locked(&dev->event_lock);
1037 e->event.sequence = drm_vblank_count(dev, pipe);
1038 e->event.crtc_id = crtc->base.id;
1039 list_add_tail(&e->base.link, &dev->vblank_event_list);
1041 EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
1044 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1045 * @crtc: the source CRTC of the vblank event
1046 * @e: the event to send
1048 * Updates sequence # and timestamp on event for the most recently processed
1049 * vblank, and sends it to userspace. Caller must hold event lock.
1051 * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
1052 * situation, especially to send out events for atomic commit operations.
1054 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1055 struct drm_pending_vblank_event *e)
1057 struct drm_device *dev = crtc->dev;
1058 unsigned int seq, pipe = drm_crtc_index(crtc);
1061 if (dev->num_crtcs > 0) {
1062 seq = drm_vblank_count_and_time(dev, pipe, &now);
1066 now = get_drm_timestamp();
1069 e->event.crtc_id = crtc->base.id;
1070 send_vblank_event(dev, e, seq, &now);
1072 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1074 static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
1076 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
1077 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
1079 if (crtc->funcs->enable_vblank)
1080 return crtc->funcs->enable_vblank(crtc);
1083 return dev->driver->enable_vblank(dev, pipe);
1087 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1092 * Zero on success or a negative error code on failure.
1094 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1096 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1099 assert_spin_locked(&dev->vbl_lock);
1101 spin_lock(&dev->vblank_time_lock);
1103 if (!vblank->enabled) {
1105 * Enable vblank irqs under vblank_time_lock protection.
1106 * All vblank count & timestamp updates are held off
1107 * until we are done reinitializing master counter and
1108 * timestamps. Filtercode in drm_handle_vblank() will
1109 * prevent double-accounting of same vblank interval.
1111 ret = __enable_vblank(dev, pipe);
1112 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1114 atomic_dec(&vblank->refcount);
1116 drm_update_vblank_count(dev, pipe, 0);
1117 /* drm_update_vblank_count() includes a wmb so we just
1118 * need to ensure that the compiler emits the write
1119 * to mark the vblank as enabled after the call
1120 * to drm_update_vblank_count().
1122 WRITE_ONCE(vblank->enabled, true);
1126 spin_unlock(&dev->vblank_time_lock);
1132 * drm_vblank_get - get a reference count on vblank events
1134 * @pipe: index of CRTC to own
1136 * Acquire a reference count on vblank events to avoid having them disabled
1139 * This is the legacy version of drm_crtc_vblank_get().
1142 * Zero on success or a negative error code on failure.
1144 static int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1146 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1147 unsigned long irqflags;
1150 if (!dev->num_crtcs)
1153 if (WARN_ON(pipe >= dev->num_crtcs))
1156 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1157 /* Going from 0->1 means we have to enable interrupts again */
1158 if (atomic_add_return(1, &vblank->refcount) == 1) {
1159 ret = drm_vblank_enable(dev, pipe);
1161 if (!vblank->enabled) {
1162 atomic_dec(&vblank->refcount);
1166 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1172 * drm_crtc_vblank_get - get a reference count on vblank events
1173 * @crtc: which CRTC to own
1175 * Acquire a reference count on vblank events to avoid having them disabled
1179 * Zero on success or a negative error code on failure.
1181 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1183 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1185 EXPORT_SYMBOL(drm_crtc_vblank_get);
1188 * drm_vblank_put - release ownership of vblank events
1190 * @pipe: index of CRTC to release
1192 * Release ownership of a given vblank counter, turning off interrupts
1193 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1195 * This is the legacy version of drm_crtc_vblank_put().
1197 static void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1199 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1201 if (WARN_ON(pipe >= dev->num_crtcs))
1204 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1207 /* Last user schedules interrupt disable */
1208 if (atomic_dec_and_test(&vblank->refcount)) {
1209 if (drm_vblank_offdelay == 0)
1211 else if (drm_vblank_offdelay < 0)
1212 vblank_disable_fn((unsigned long)vblank);
1213 else if (!dev->vblank_disable_immediate)
1214 mod_timer(&vblank->disable_timer,
1215 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1220 * drm_crtc_vblank_put - give up ownership of vblank events
1221 * @crtc: which counter to give up
1223 * Release ownership of a given vblank counter, turning off interrupts
1224 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1226 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1228 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1230 EXPORT_SYMBOL(drm_crtc_vblank_put);
1233 * drm_wait_one_vblank - wait for one vblank
1237 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1238 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1239 * due to lack of driver support or because the crtc is off.
1241 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1243 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1247 if (WARN_ON(pipe >= dev->num_crtcs))
1250 ret = drm_vblank_get(dev, pipe);
1251 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1254 last = drm_vblank_count(dev, pipe);
1256 ret = wait_event_timeout(vblank->queue,
1257 last != drm_vblank_count(dev, pipe),
1258 msecs_to_jiffies(100));
1260 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1262 drm_vblank_put(dev, pipe);
1264 EXPORT_SYMBOL(drm_wait_one_vblank);
1267 * drm_crtc_wait_one_vblank - wait for one vblank
1270 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1271 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1272 * due to lack of driver support or because the crtc is off.
1274 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1276 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1278 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1281 * drm_crtc_vblank_off - disable vblank events on a CRTC
1282 * @crtc: CRTC in question
1284 * Drivers can use this function to shut down the vblank interrupt handling when
1285 * disabling a crtc. This function ensures that the latest vblank frame count is
1286 * stored so that drm_vblank_on can restore it again.
1288 * Drivers must use this function when the hardware vblank counter can get
1289 * reset, e.g. when suspending.
1291 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1293 struct drm_device *dev = crtc->dev;
1294 unsigned int pipe = drm_crtc_index(crtc);
1295 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1296 struct drm_pending_vblank_event *e, *t;
1298 unsigned long irqflags;
1301 if (WARN_ON(pipe >= dev->num_crtcs))
1304 spin_lock_irqsave(&dev->event_lock, irqflags);
1306 spin_lock(&dev->vbl_lock);
1307 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1308 pipe, vblank->enabled, vblank->inmodeset);
1310 /* Avoid redundant vblank disables without previous
1311 * drm_crtc_vblank_on(). */
1312 if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
1313 vblank_disable_and_save(dev, pipe);
1315 wake_up(&vblank->queue);
1318 * Prevent subsequent drm_vblank_get() from re-enabling
1319 * the vblank interrupt by bumping the refcount.
1321 if (!vblank->inmodeset) {
1322 atomic_inc(&vblank->refcount);
1323 vblank->inmodeset = 1;
1325 spin_unlock(&dev->vbl_lock);
1327 /* Send any queued vblank events, lest the natives grow disquiet */
1328 seq = drm_vblank_count_and_time(dev, pipe, &now);
1330 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1331 if (e->pipe != pipe)
1333 DRM_DEBUG("Sending premature vblank event on disable: "
1334 "wanted %u, current %u\n",
1335 e->event.sequence, seq);
1336 list_del(&e->base.link);
1337 drm_vblank_put(dev, pipe);
1338 send_vblank_event(dev, e, seq, &now);
1340 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1342 EXPORT_SYMBOL(drm_crtc_vblank_off);
1345 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1346 * @crtc: CRTC in question
1348 * Drivers can use this function to reset the vblank state to off at load time.
1349 * Drivers should use this together with the drm_crtc_vblank_off() and
1350 * drm_crtc_vblank_on() functions. The difference compared to
1351 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1352 * and hence doesn't need to call any driver hooks.
1354 void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1356 struct drm_device *dev = crtc->dev;
1357 unsigned long irqflags;
1358 unsigned int pipe = drm_crtc_index(crtc);
1359 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1361 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1363 * Prevent subsequent drm_vblank_get() from enabling the vblank
1364 * interrupt by bumping the refcount.
1366 if (!vblank->inmodeset) {
1367 atomic_inc(&vblank->refcount);
1368 vblank->inmodeset = 1;
1370 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1372 WARN_ON(!list_empty(&dev->vblank_event_list));
1374 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1377 * drm_crtc_vblank_on - enable vblank events on a CRTC
1378 * @crtc: CRTC in question
1380 * This functions restores the vblank interrupt state captured with
1381 * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and
1382 * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called
1383 * in driver load code to reflect the current hardware state of the crtc.
1385 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1387 struct drm_device *dev = crtc->dev;
1388 unsigned int pipe = drm_crtc_index(crtc);
1389 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1390 unsigned long irqflags;
1392 if (WARN_ON(pipe >= dev->num_crtcs))
1395 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1396 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1397 pipe, vblank->enabled, vblank->inmodeset);
1399 /* Drop our private "prevent drm_vblank_get" refcount */
1400 if (vblank->inmodeset) {
1401 atomic_dec(&vblank->refcount);
1402 vblank->inmodeset = 0;
1405 drm_reset_vblank_timestamp(dev, pipe);
1408 * re-enable interrupts if there are users left, or the
1409 * user wishes vblank interrupts to be enabled all the time.
1411 if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0)
1412 WARN_ON(drm_vblank_enable(dev, pipe));
1413 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1415 EXPORT_SYMBOL(drm_crtc_vblank_on);
1417 static void drm_legacy_vblank_pre_modeset(struct drm_device *dev,
1420 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1422 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1423 if (!dev->num_crtcs)
1426 if (WARN_ON(pipe >= dev->num_crtcs))
1430 * To avoid all the problems that might happen if interrupts
1431 * were enabled/disabled around or between these calls, we just
1432 * have the kernel take a reference on the CRTC (just once though
1433 * to avoid corrupting the count if multiple, mismatch calls occur),
1434 * so that interrupts remain enabled in the interim.
1436 if (!vblank->inmodeset) {
1437 vblank->inmodeset = 0x1;
1438 if (drm_vblank_get(dev, pipe) == 0)
1439 vblank->inmodeset |= 0x2;
1443 static void drm_legacy_vblank_post_modeset(struct drm_device *dev,
1446 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1447 unsigned long irqflags;
1449 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1450 if (!dev->num_crtcs)
1453 if (WARN_ON(pipe >= dev->num_crtcs))
1456 if (vblank->inmodeset) {
1457 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1458 drm_reset_vblank_timestamp(dev, pipe);
1459 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1461 if (vblank->inmodeset & 0x2)
1462 drm_vblank_put(dev, pipe);
1464 vblank->inmodeset = 0;
1468 int drm_legacy_modeset_ctl(struct drm_device *dev, void *data,
1469 struct drm_file *file_priv)
1471 struct drm_modeset_ctl *modeset = data;
1474 /* If drm_vblank_init() hasn't been called yet, just no-op */
1475 if (!dev->num_crtcs)
1478 /* KMS drivers handle this internally */
1479 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1482 pipe = modeset->crtc;
1483 if (pipe >= dev->num_crtcs)
1486 switch (modeset->cmd) {
1487 case _DRM_PRE_MODESET:
1488 drm_legacy_vblank_pre_modeset(dev, pipe);
1490 case _DRM_POST_MODESET:
1491 drm_legacy_vblank_post_modeset(dev, pipe);
1500 static inline bool vblank_passed(u32 seq, u32 ref)
1502 return (seq - ref) <= (1 << 23);
1505 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1506 union drm_wait_vblank *vblwait,
1507 struct drm_file *file_priv)
1509 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1510 struct drm_pending_vblank_event *e;
1512 unsigned long flags;
1516 e = kzalloc(sizeof(*e), GFP_KERNEL);
1523 e->event.base.type = DRM_EVENT_VBLANK;
1524 e->event.base.length = sizeof(e->event);
1525 e->event.user_data = vblwait->request.signal;
1527 spin_lock_irqsave(&dev->event_lock, flags);
1530 * drm_crtc_vblank_off() might have been called after we called
1531 * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
1532 * vblank disable, so no need for further locking. The reference from
1533 * drm_vblank_get() protects against vblank disable from another source.
1535 if (!READ_ONCE(vblank->enabled)) {
1540 ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
1546 seq = drm_vblank_count_and_time(dev, pipe, &now);
1548 DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n",
1549 vblwait->request.sequence, seq, pipe);
1551 trace_drm_vblank_event_queued(file_priv, pipe,
1552 vblwait->request.sequence);
1554 e->event.sequence = vblwait->request.sequence;
1555 if (vblank_passed(seq, vblwait->request.sequence)) {
1556 drm_vblank_put(dev, pipe);
1557 send_vblank_event(dev, e, seq, &now);
1558 vblwait->reply.sequence = seq;
1560 /* drm_handle_vblank_events will call drm_vblank_put */
1561 list_add_tail(&e->base.link, &dev->vblank_event_list);
1562 vblwait->reply.sequence = vblwait->request.sequence;
1565 spin_unlock_irqrestore(&dev->event_lock, flags);
1570 spin_unlock_irqrestore(&dev->event_lock, flags);
1573 drm_vblank_put(dev, pipe);
1577 static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait)
1579 if (vblwait->request.sequence)
1582 return _DRM_VBLANK_RELATIVE ==
1583 (vblwait->request.type & (_DRM_VBLANK_TYPES_MASK |
1585 _DRM_VBLANK_NEXTONMISS));
1591 * \param inode device inode.
1592 * \param file_priv DRM file private.
1593 * \param cmd command.
1594 * \param data user argument, pointing to a drm_wait_vblank structure.
1595 * \return zero on success or a negative number on failure.
1597 * This function enables the vblank interrupt on the pipe requested, then
1598 * sleeps waiting for the requested sequence number to occur, and drops
1599 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1600 * after a timeout with no further vblank waits scheduled).
1602 int drm_wait_vblank(struct drm_device *dev, void *data,
1603 struct drm_file *file_priv)
1605 struct drm_vblank_crtc *vblank;
1606 union drm_wait_vblank *vblwait = data;
1608 unsigned int flags, seq, pipe, high_pipe;
1610 if (!dev->irq_enabled)
1613 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1616 if (vblwait->request.type &
1617 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1618 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1619 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1620 vblwait->request.type,
1621 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1622 _DRM_VBLANK_HIGH_CRTC_MASK));
1626 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1627 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1629 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1631 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1632 if (pipe >= dev->num_crtcs)
1635 vblank = &dev->vblank[pipe];
1637 /* If the counter is currently enabled and accurate, short-circuit
1638 * queries to return the cached timestamp of the last vblank.
1640 if (dev->vblank_disable_immediate &&
1641 drm_wait_vblank_is_query(vblwait) &&
1642 READ_ONCE(vblank->enabled)) {
1645 vblwait->reply.sequence =
1646 drm_vblank_count_and_time(dev, pipe, &now);
1647 vblwait->reply.tval_sec = now.tv_sec;
1648 vblwait->reply.tval_usec = now.tv_usec;
1652 ret = drm_vblank_get(dev, pipe);
1654 DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret);
1657 seq = drm_vblank_count(dev, pipe);
1659 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1660 case _DRM_VBLANK_RELATIVE:
1661 vblwait->request.sequence += seq;
1662 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1663 case _DRM_VBLANK_ABSOLUTE:
1670 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1671 vblank_passed(seq, vblwait->request.sequence))
1672 vblwait->request.sequence = seq + 1;
1674 if (flags & _DRM_VBLANK_EVENT) {
1675 /* must hold on to the vblank ref until the event fires
1676 * drm_vblank_put will be called asynchronously
1678 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1681 if (vblwait->request.sequence != seq) {
1682 DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
1683 vblwait->request.sequence, pipe);
1684 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1685 vblank_passed(drm_vblank_count(dev, pipe),
1686 vblwait->request.sequence) ||
1687 !READ_ONCE(vblank->enabled));
1690 if (ret != -EINTR) {
1693 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1694 vblwait->reply.tval_sec = now.tv_sec;
1695 vblwait->reply.tval_usec = now.tv_usec;
1697 DRM_DEBUG("crtc %d returning %u to client\n",
1698 pipe, vblwait->reply.sequence);
1700 DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe);
1704 drm_vblank_put(dev, pipe);
1708 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1710 struct drm_pending_vblank_event *e, *t;
1714 assert_spin_locked(&dev->event_lock);
1716 seq = drm_vblank_count_and_time(dev, pipe, &now);
1718 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1719 if (e->pipe != pipe)
1721 if (!vblank_passed(seq, e->event.sequence))
1724 DRM_DEBUG("vblank event on %u, current %u\n",
1725 e->event.sequence, seq);
1727 list_del(&e->base.link);
1728 drm_vblank_put(dev, pipe);
1729 send_vblank_event(dev, e, seq, &now);
1732 trace_drm_vblank_event(pipe, seq);
1736 * drm_handle_vblank - handle a vblank event
1738 * @pipe: index of CRTC where this event occurred
1740 * Drivers should call this routine in their vblank interrupt handlers to
1741 * update the vblank counter and send any signals that may be pending.
1743 * This is the legacy version of drm_crtc_handle_vblank().
1745 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1747 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1748 unsigned long irqflags;
1751 if (WARN_ON_ONCE(!dev->num_crtcs))
1754 if (WARN_ON(pipe >= dev->num_crtcs))
1757 spin_lock_irqsave(&dev->event_lock, irqflags);
1759 /* Need timestamp lock to prevent concurrent execution with
1760 * vblank enable/disable, as this would cause inconsistent
1761 * or corrupted timestamps and vblank counts.
1763 spin_lock(&dev->vblank_time_lock);
1765 /* Vblank irq handling disabled. Nothing to do. */
1766 if (!vblank->enabled) {
1767 spin_unlock(&dev->vblank_time_lock);
1768 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1772 drm_update_vblank_count(dev, pipe, true);
1774 spin_unlock(&dev->vblank_time_lock);
1776 wake_up(&vblank->queue);
1778 /* With instant-off, we defer disabling the interrupt until after
1779 * we finish processing the following vblank after all events have
1780 * been signaled. The disable has to be last (after
1781 * drm_handle_vblank_events) so that the timestamp is always accurate.
1783 disable_irq = (dev->vblank_disable_immediate &&
1784 drm_vblank_offdelay > 0 &&
1785 !atomic_read(&vblank->refcount));
1787 drm_handle_vblank_events(dev, pipe);
1789 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1792 vblank_disable_fn((unsigned long)vblank);
1796 EXPORT_SYMBOL(drm_handle_vblank);
1799 * drm_crtc_handle_vblank - handle a vblank event
1800 * @crtc: where this event occurred
1802 * Drivers should call this routine in their vblank interrupt handlers to
1803 * update the vblank counter and send any signals that may be pending.
1805 * This is the native KMS version of drm_handle_vblank().
1808 * True if the event was successfully handled, false on failure.
1810 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1812 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1814 EXPORT_SYMBOL(drm_crtc_handle_vblank);