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"
38 #include <linux/interrupt.h> /* For task queue support */
39 #include <linux/slab.h>
41 #include <linux/vgaarb.h>
42 #include <linux/export.h>
44 /* Access macro for slots in vblank timestamp ringbuffer. */
45 #define vblanktimestamp(dev, crtc, count) \
46 ((dev)->vblank[crtc].time[(count) % DRM_VBLANKTIME_RBSIZE])
48 /* Retry timestamp calculation up to 3 times to satisfy
49 * drm_timestamp_precision before giving up.
51 #define DRM_TIMESTAMP_MAXRETRIES 3
53 /* Threshold in nanoseconds for detection of redundant
54 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
56 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
59 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
60 struct timeval *tvblank, unsigned flags);
63 * drm_update_vblank_count - update the master vblank counter
65 * @crtc: counter to update
67 * Call back into the driver to update the appropriate vblank counter
68 * (specified by @crtc). Deal with wraparound, if it occurred, and
69 * update the last read value so we can deal with wraparound on the next
72 * Only necessary when going from off->on, to account for frames we
73 * didn't get an interrupt for.
75 * Note: caller must hold dev->vbl_lock since this reads & writes
76 * device vblank fields.
78 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
80 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
81 u32 cur_vblank, diff, tslot;
83 struct timeval t_vblank;
86 * Interrupts were disabled prior to this call, so deal with counter
88 * NOTE! It's possible we lost a full dev->max_vblank_count events
89 * here if the register is small or we had vblank interrupts off for
92 * We repeat the hardware vblank counter & timestamp query until
93 * we get consistent results. This to prevent races between gpu
94 * updating its hardware counter while we are retrieving the
95 * corresponding vblank timestamp.
98 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
99 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
100 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
102 /* Deal with counter wrap */
103 diff = cur_vblank - vblank->last;
104 if (cur_vblank < vblank->last) {
105 diff += dev->max_vblank_count;
107 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
108 crtc, vblank->last, cur_vblank, diff);
111 DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
114 /* Reinitialize corresponding vblank timestamp if high-precision query
115 * available. Skip this step if query unsupported or failed. Will
116 * reinitialize delayed at next vblank interrupt in that case.
119 tslot = atomic_read(&vblank->count) + diff;
120 vblanktimestamp(dev, crtc, tslot) = t_vblank;
123 smp_mb__before_atomic();
124 atomic_add(diff, &vblank->count);
125 smp_mb__after_atomic();
129 * Disable vblank irq's on crtc, make sure that last vblank count
130 * of hardware and corresponding consistent software vblank counter
131 * are preserved, even if there are any spurious vblank irq's after
134 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
136 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
137 unsigned long irqflags;
141 struct timeval tvblank;
142 int count = DRM_TIMESTAMP_MAXRETRIES;
144 /* Prevent vblank irq processing while disabling vblank irqs,
145 * so no updates of timestamps or count can happen after we've
146 * disabled. Needed to prevent races in case of delayed irq's.
148 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
151 * If the vblank interrupt was already disbled update the count
152 * and timestamp to maintain the appearance that the counter
153 * has been ticking all along until this time. This makes the
154 * count account for the entire time between drm_vblank_on() and
157 * But only do this if precise vblank timestamps are available.
158 * Otherwise we might read a totally bogus timestamp since drivers
159 * lacking precise timestamp support rely upon sampling the system clock
160 * at vblank interrupt time. Which obviously won't work out well if the
161 * vblank interrupt is disabled.
163 if (!vblank->enabled &&
164 drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0)) {
165 drm_update_vblank_count(dev, crtc);
166 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
170 dev->driver->disable_vblank(dev, crtc);
171 vblank->enabled = false;
173 /* No further vblank irq's will be processed after
174 * this point. Get current hardware vblank count and
175 * vblank timestamp, repeat until they are consistent.
177 * FIXME: There is still a race condition here and in
178 * drm_update_vblank_count() which can cause off-by-one
179 * reinitialization of software vblank counter. If gpu
180 * vblank counter doesn't increment exactly at the leading
181 * edge of a vblank interval, then we can lose 1 count if
182 * we happen to execute between start of vblank and the
183 * delayed gpu counter increment.
186 vblank->last = dev->driver->get_vblank_counter(dev, crtc);
187 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
188 } while (vblank->last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
193 /* Compute time difference to stored timestamp of last vblank
194 * as updated by last invocation of drm_handle_vblank() in vblank irq.
196 vblcount = atomic_read(&vblank->count);
197 diff_ns = timeval_to_ns(&tvblank) -
198 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
200 /* If there is at least 1 msec difference between the last stored
201 * timestamp and tvblank, then we are currently executing our
202 * disable inside a new vblank interval, the tvblank timestamp
203 * corresponds to this new vblank interval and the irq handler
204 * for this vblank didn't run yet and won't run due to our disable.
205 * Therefore we need to do the job of drm_handle_vblank() and
206 * increment the vblank counter by one to account for this vblank.
208 * Skip this step if there isn't any high precision timestamp
209 * available. In that case we can't account for this and just
212 if (vblrc && (abs64(diff_ns) > 1000000)) {
213 /* Store new timestamp in ringbuffer. */
214 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
216 /* Increment cooked vblank count. This also atomically commits
217 * the timestamp computed above.
219 smp_mb__before_atomic();
220 atomic_inc(&vblank->count);
221 smp_mb__after_atomic();
224 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
227 static void vblank_disable_fn(unsigned long arg)
229 struct drm_vblank_crtc *vblank = (void *)arg;
230 struct drm_device *dev = vblank->dev;
231 unsigned long irqflags;
232 int crtc = vblank->crtc;
234 if (!dev->vblank_disable_allowed)
237 spin_lock_irqsave(&dev->vbl_lock, irqflags);
238 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
239 DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
240 vblank_disable_and_save(dev, crtc);
242 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
246 * drm_vblank_cleanup - cleanup vblank support
249 * This function cleans up any resources allocated in drm_vblank_init.
251 void drm_vblank_cleanup(struct drm_device *dev)
254 unsigned long irqflags;
256 /* Bail if the driver didn't call drm_vblank_init() */
257 if (dev->num_crtcs == 0)
260 for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
261 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
263 del_timer_sync(&vblank->disable_timer);
265 spin_lock_irqsave(&dev->vbl_lock, irqflags);
266 vblank_disable_and_save(dev, crtc);
267 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
274 EXPORT_SYMBOL(drm_vblank_cleanup);
277 * drm_vblank_init - initialize vblank support
279 * @num_crtcs: number of crtcs supported by @dev
281 * This function initializes vblank support for @num_crtcs display pipelines.
284 * Zero on success or a negative error code on failure.
286 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
288 int i, ret = -ENOMEM;
290 spin_lock_init(&dev->vbl_lock);
291 spin_lock_init(&dev->vblank_time_lock);
293 dev->num_crtcs = num_crtcs;
295 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
299 for (i = 0; i < num_crtcs; i++) {
300 struct drm_vblank_crtc *vblank = &dev->vblank[i];
304 init_waitqueue_head(&vblank->queue);
305 setup_timer(&vblank->disable_timer, vblank_disable_fn,
306 (unsigned long)vblank);
309 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
311 /* Driver specific high-precision vblank timestamping supported? */
312 if (dev->driver->get_vblank_timestamp)
313 DRM_INFO("Driver supports precise vblank timestamp query.\n");
315 DRM_INFO("No driver support for vblank timestamp query.\n");
317 dev->vblank_disable_allowed = false;
325 EXPORT_SYMBOL(drm_vblank_init);
327 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
329 struct drm_device *dev = cookie;
331 if (dev->driver->vgaarb_irq) {
332 dev->driver->vgaarb_irq(dev, state);
336 if (!dev->irq_enabled)
340 if (dev->driver->irq_uninstall)
341 dev->driver->irq_uninstall(dev);
343 if (dev->driver->irq_preinstall)
344 dev->driver->irq_preinstall(dev);
345 if (dev->driver->irq_postinstall)
346 dev->driver->irq_postinstall(dev);
351 * drm_irq_install - install IRQ handler
353 * @irq: IRQ number to install the handler for
355 * Initializes the IRQ related data. Installs the handler, calling the driver
356 * irq_preinstall() and irq_postinstall() functions before and after the
359 * This is the simplified helper interface provided for drivers with no special
360 * needs. Drivers which need to install interrupt handlers for multiple
361 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
362 * that vblank interrupts are available.
365 * Zero on success or a negative error code on failure.
367 int drm_irq_install(struct drm_device *dev, int irq)
370 unsigned long sh_flags = 0;
372 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
378 /* Driver must have been initialized */
379 if (!dev->dev_private)
382 if (dev->irq_enabled)
384 dev->irq_enabled = true;
386 DRM_DEBUG("irq=%d\n", irq);
388 /* Before installing handler */
389 if (dev->driver->irq_preinstall)
390 dev->driver->irq_preinstall(dev);
392 /* Install handler */
393 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
394 sh_flags = IRQF_SHARED;
396 ret = request_irq(irq, dev->driver->irq_handler,
397 sh_flags, dev->driver->name, dev);
400 dev->irq_enabled = false;
404 if (!drm_core_check_feature(dev, DRIVER_MODESET))
405 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
407 /* After installing handler */
408 if (dev->driver->irq_postinstall)
409 ret = dev->driver->irq_postinstall(dev);
412 dev->irq_enabled = false;
413 if (!drm_core_check_feature(dev, DRIVER_MODESET))
414 vga_client_register(dev->pdev, NULL, NULL, NULL);
422 EXPORT_SYMBOL(drm_irq_install);
425 * drm_irq_uninstall - uninstall the IRQ handler
428 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
429 * This should only be called by drivers which used drm_irq_install() to set up
430 * their interrupt handler. Other drivers must only reset
431 * drm_device->irq_enabled to false.
433 * Note that for kernel modesetting drivers it is a bug if this function fails.
434 * The sanity checks are only to catch buggy user modesetting drivers which call
435 * the same function through an ioctl.
438 * Zero on success or a negative error code on failure.
440 int drm_irq_uninstall(struct drm_device *dev)
442 unsigned long irqflags;
446 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
449 irq_enabled = dev->irq_enabled;
450 dev->irq_enabled = false;
453 * Wake up any waiters so they don't hang.
455 if (dev->num_crtcs) {
456 spin_lock_irqsave(&dev->vbl_lock, irqflags);
457 for (i = 0; i < dev->num_crtcs; i++) {
458 struct drm_vblank_crtc *vblank = &dev->vblank[i];
460 wake_up(&vblank->queue);
461 vblank->enabled = false;
463 dev->driver->get_vblank_counter(dev, i);
465 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
471 DRM_DEBUG("irq=%d\n", dev->irq);
473 if (!drm_core_check_feature(dev, DRIVER_MODESET))
474 vga_client_register(dev->pdev, NULL, NULL, NULL);
476 if (dev->driver->irq_uninstall)
477 dev->driver->irq_uninstall(dev);
479 free_irq(dev->irq, dev);
483 EXPORT_SYMBOL(drm_irq_uninstall);
488 * \param inode device inode.
489 * \param file_priv DRM file private.
490 * \param cmd command.
491 * \param arg user argument, pointing to a drm_control structure.
492 * \return zero on success or a negative number on failure.
494 * Calls irq_install() or irq_uninstall() according to \p arg.
496 int drm_control(struct drm_device *dev, void *data,
497 struct drm_file *file_priv)
499 struct drm_control *ctl = data;
502 /* if we haven't irq we fallback for compatibility reasons -
503 * this used to be a separate function in drm_dma.h
506 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
508 if (drm_core_check_feature(dev, DRIVER_MODESET))
510 /* UMS was only ever support on pci devices. */
511 if (WARN_ON(!dev->pdev))
515 case DRM_INST_HANDLER:
516 irq = dev->pdev->irq;
518 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
521 mutex_lock(&dev->struct_mutex);
522 ret = drm_irq_install(dev, irq);
523 mutex_unlock(&dev->struct_mutex);
526 case DRM_UNINST_HANDLER:
527 mutex_lock(&dev->struct_mutex);
528 ret = drm_irq_uninstall(dev);
529 mutex_unlock(&dev->struct_mutex);
538 * drm_calc_timestamping_constants - calculate vblank timestamp constants
539 * @crtc: drm_crtc whose timestamp constants should be updated.
540 * @mode: display mode containing the scanout timings
542 * Calculate and store various constants which are later
543 * needed by vblank and swap-completion timestamping, e.g,
544 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
545 * derived from CRTC's true scanout timing, so they take
546 * things like panel scaling or other adjustments into account.
548 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
549 const struct drm_display_mode *mode)
551 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
552 int dotclock = mode->crtc_clock;
554 /* Valid dotclock? */
556 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
559 * Convert scanline length in pixels and video
560 * dot clock to line duration, frame duration
561 * and pixel duration in nanoseconds:
563 pixeldur_ns = 1000000 / dotclock;
564 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
565 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
568 * Fields of interlaced scanout modes are only half a frame duration.
570 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
573 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
576 crtc->pixeldur_ns = pixeldur_ns;
577 crtc->linedur_ns = linedur_ns;
578 crtc->framedur_ns = framedur_ns;
580 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
581 crtc->base.id, mode->crtc_htotal,
582 mode->crtc_vtotal, mode->crtc_vdisplay);
583 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
584 crtc->base.id, dotclock, framedur_ns,
585 linedur_ns, pixeldur_ns);
587 EXPORT_SYMBOL(drm_calc_timestamping_constants);
590 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
592 * @crtc: Which CRTC's vblank timestamp to retrieve
593 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
594 * On return contains true maximum error of timestamp
595 * @vblank_time: Pointer to struct timeval which should receive the timestamp
596 * @flags: Flags to pass to driver:
598 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
599 * @refcrtc: CRTC which defines scanout timing
600 * @mode: mode which defines the scanout timings
602 * Implements calculation of exact vblank timestamps from given drm_display_mode
603 * timings and current video scanout position of a CRTC. This can be called from
604 * within get_vblank_timestamp() implementation of a kms driver to implement the
605 * actual timestamping.
607 * Should return timestamps conforming to the OML_sync_control OpenML
608 * extension specification. The timestamp corresponds to the end of
609 * the vblank interval, aka start of scanout of topmost-leftmost display
610 * pixel in the following video frame.
612 * Requires support for optional dev->driver->get_scanout_position()
613 * in kms driver, plus a bit of setup code to provide a drm_display_mode
614 * that corresponds to the true scanout timing.
616 * The current implementation only handles standard video modes. It
617 * returns as no operation if a doublescan or interlaced video mode is
618 * active. Higher level code is expected to handle this.
621 * Negative value on error, failure or if not supported in current
624 * -EINVAL - Invalid CRTC.
625 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
626 * -ENOTSUPP - Function not supported in current display mode.
627 * -EIO - Failed, e.g., due to failed scanout position query.
629 * Returns or'ed positive status flags on success:
631 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
632 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
635 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
637 struct timeval *vblank_time,
639 const struct drm_crtc *refcrtc,
640 const struct drm_display_mode *mode)
642 struct timeval tv_etime;
643 ktime_t stime, etime;
646 int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
649 if (crtc < 0 || crtc >= dev->num_crtcs) {
650 DRM_ERROR("Invalid crtc %d\n", crtc);
654 /* Scanout position query not supported? Should not happen. */
655 if (!dev->driver->get_scanout_position) {
656 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
660 /* Durations of frames, lines, pixels in nanoseconds. */
661 framedur_ns = refcrtc->framedur_ns;
662 linedur_ns = refcrtc->linedur_ns;
663 pixeldur_ns = refcrtc->pixeldur_ns;
665 /* If mode timing undefined, just return as no-op:
666 * Happens during initial modesetting of a crtc.
668 if (framedur_ns == 0) {
669 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
673 /* Get current scanout position with system timestamp.
674 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
675 * if single query takes longer than max_error nanoseconds.
677 * This guarantees a tight bound on maximum error if
678 * code gets preempted or delayed for some reason.
680 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
682 * Get vertical and horizontal scanout position vpos, hpos,
683 * and bounding timestamps stime, etime, pre/post query.
685 vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
686 &hpos, &stime, &etime);
688 /* Return as no-op if scanout query unsupported or failed. */
689 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
690 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
695 /* Compute uncertainty in timestamp of scanout position query. */
696 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
698 /* Accept result with < max_error nsecs timing uncertainty. */
699 if (duration_ns <= *max_error)
703 /* Noisy system timing? */
704 if (i == DRM_TIMESTAMP_MAXRETRIES) {
705 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
706 crtc, duration_ns/1000, *max_error/1000, i);
709 /* Return upper bound of timestamp precision error. */
710 *max_error = duration_ns;
712 /* Check if in vblank area:
713 * vpos is >=0 in video scanout area, but negative
714 * within vblank area, counting down the number of lines until
717 invbl = vbl_status & DRM_SCANOUTPOS_IN_VBLANK;
719 /* Convert scanout position into elapsed time at raw_time query
720 * since start of scanout at first display scanline. delta_ns
721 * can be negative if start of scanout hasn't happened yet.
723 delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
725 if (!drm_timestamp_monotonic)
726 etime = ktime_mono_to_real(etime);
728 /* save this only for debugging purposes */
729 tv_etime = ktime_to_timeval(etime);
730 /* Subtract time delta from raw timestamp to get final
731 * vblank_time timestamp for end of vblank.
734 etime = ktime_add_ns(etime, -delta_ns);
736 etime = ktime_sub_ns(etime, delta_ns);
737 *vblank_time = ktime_to_timeval(etime);
739 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
740 crtc, (int)vbl_status, hpos, vpos,
741 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
742 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
743 duration_ns/1000, i);
745 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
747 vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
751 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
753 static struct timeval get_drm_timestamp(void)
757 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
758 return ktime_to_timeval(now);
762 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
765 * @crtc: which CRTC's vblank timestamp to retrieve
766 * @tvblank: Pointer to target struct timeval which should receive the timestamp
767 * @flags: Flags to pass to driver:
769 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
771 * Fetches the system timestamp corresponding to the time of the most recent
772 * vblank interval on specified CRTC. May call into kms-driver to
773 * compute the timestamp with a high-precision GPU specific method.
775 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
776 * call, i.e., it isn't very precisely locked to the true vblank.
779 * True if timestamp is considered to be very precise, false otherwise.
782 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
783 struct timeval *tvblank, unsigned flags)
787 /* Define requested maximum error on timestamps (nanoseconds). */
788 int max_error = (int) drm_timestamp_precision * 1000;
790 /* Query driver if possible and precision timestamping enabled. */
791 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
792 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
798 /* GPU high precision timestamp query unsupported or failed.
799 * Return current monotonic/gettimeofday timestamp as best estimate.
801 *tvblank = get_drm_timestamp();
807 * drm_vblank_count - retrieve "cooked" vblank counter value
809 * @crtc: which counter to retrieve
811 * Fetches the "cooked" vblank count value that represents the number of
812 * vblank events since the system was booted, including lost events due to
813 * modesetting activity.
816 * The software vblank counter.
818 u32 drm_vblank_count(struct drm_device *dev, int crtc)
820 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
822 if (WARN_ON(crtc >= dev->num_crtcs))
824 return atomic_read(&vblank->count);
826 EXPORT_SYMBOL(drm_vblank_count);
829 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
830 * and the system timestamp corresponding to that vblank counter value.
833 * @crtc: which counter to retrieve
834 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
836 * Fetches the "cooked" vblank count value that represents the number of
837 * vblank events since the system was booted, including lost events due to
838 * modesetting activity. Returns corresponding system timestamp of the time
839 * of the vblank interval that corresponds to the current vblank counter value.
841 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
842 struct timeval *vblanktime)
844 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
847 if (WARN_ON(crtc >= dev->num_crtcs))
850 /* Read timestamp from slot of _vblank_time ringbuffer
851 * that corresponds to current vblank count. Retry if
852 * count has incremented during readout. This works like
856 cur_vblank = atomic_read(&vblank->count);
857 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
859 } while (cur_vblank != atomic_read(&vblank->count));
863 EXPORT_SYMBOL(drm_vblank_count_and_time);
865 static void send_vblank_event(struct drm_device *dev,
866 struct drm_pending_vblank_event *e,
867 unsigned long seq, struct timeval *now)
869 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
870 e->event.sequence = seq;
871 e->event.tv_sec = now->tv_sec;
872 e->event.tv_usec = now->tv_usec;
874 list_add_tail(&e->base.link,
875 &e->base.file_priv->event_list);
876 wake_up_interruptible(&e->base.file_priv->event_wait);
877 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
882 * drm_send_vblank_event - helper to send vblank event after pageflip
884 * @crtc: CRTC in question
885 * @e: the event to send
887 * Updates sequence # and timestamp on event, and sends it to userspace.
888 * Caller must hold event lock.
890 void drm_send_vblank_event(struct drm_device *dev, int crtc,
891 struct drm_pending_vblank_event *e)
896 seq = drm_vblank_count_and_time(dev, crtc, &now);
900 now = get_drm_timestamp();
903 send_vblank_event(dev, e, seq, &now);
905 EXPORT_SYMBOL(drm_send_vblank_event);
908 * drm_vblank_enable - enable the vblank interrupt on a CRTC
910 * @crtc: CRTC in question
912 static int drm_vblank_enable(struct drm_device *dev, int crtc)
914 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
917 assert_spin_locked(&dev->vbl_lock);
919 spin_lock(&dev->vblank_time_lock);
921 if (!vblank->enabled) {
923 * Enable vblank irqs under vblank_time_lock protection.
924 * All vblank count & timestamp updates are held off
925 * until we are done reinitializing master counter and
926 * timestamps. Filtercode in drm_handle_vblank() will
927 * prevent double-accounting of same vblank interval.
929 ret = dev->driver->enable_vblank(dev, crtc);
930 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
932 atomic_dec(&vblank->refcount);
934 vblank->enabled = true;
935 drm_update_vblank_count(dev, crtc);
939 spin_unlock(&dev->vblank_time_lock);
945 * drm_vblank_get - get a reference count on vblank events
947 * @crtc: which CRTC to own
949 * Acquire a reference count on vblank events to avoid having them disabled
952 * This is the legacy version of drm_crtc_vblank_get().
955 * Zero on success, nonzero on failure.
957 int drm_vblank_get(struct drm_device *dev, int crtc)
959 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
960 unsigned long irqflags;
963 if (WARN_ON(crtc >= dev->num_crtcs))
966 spin_lock_irqsave(&dev->vbl_lock, irqflags);
967 /* Going from 0->1 means we have to enable interrupts again */
968 if (atomic_add_return(1, &vblank->refcount) == 1) {
969 ret = drm_vblank_enable(dev, crtc);
971 if (!vblank->enabled) {
972 atomic_dec(&vblank->refcount);
976 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
980 EXPORT_SYMBOL(drm_vblank_get);
983 * drm_crtc_vblank_get - get a reference count on vblank events
984 * @crtc: which CRTC to own
986 * Acquire a reference count on vblank events to avoid having them disabled
989 * This is the native kms version of drm_vblank_off().
992 * Zero on success, nonzero on failure.
994 int drm_crtc_vblank_get(struct drm_crtc *crtc)
996 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
998 EXPORT_SYMBOL(drm_crtc_vblank_get);
1001 * drm_vblank_put - give up ownership of vblank events
1003 * @crtc: which counter to give up
1005 * Release ownership of a given vblank counter, turning off interrupts
1006 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1008 * This is the legacy version of drm_crtc_vblank_put().
1010 void drm_vblank_put(struct drm_device *dev, int crtc)
1012 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1014 BUG_ON(atomic_read(&vblank->refcount) == 0);
1016 if (WARN_ON(crtc >= dev->num_crtcs))
1019 /* Last user schedules interrupt disable */
1020 if (atomic_dec_and_test(&vblank->refcount)) {
1021 if (drm_vblank_offdelay == 0)
1023 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1024 vblank_disable_fn((unsigned long)vblank);
1026 mod_timer(&vblank->disable_timer,
1027 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1030 EXPORT_SYMBOL(drm_vblank_put);
1033 * drm_crtc_vblank_put - give up ownership of vblank events
1034 * @crtc: which counter to give up
1036 * Release ownership of a given vblank counter, turning off interrupts
1037 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1039 * This is the native kms version of drm_vblank_put().
1041 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1043 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1045 EXPORT_SYMBOL(drm_crtc_vblank_put);
1048 * drm_wait_one_vblank - wait for one vblank
1052 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1053 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1054 * due to lack of driver support or because the crtc is off.
1056 void drm_wait_one_vblank(struct drm_device *dev, int crtc)
1061 ret = drm_vblank_get(dev, crtc);
1065 last = drm_vblank_count(dev, crtc);
1067 ret = wait_event_timeout(dev->vblank[crtc].queue,
1068 last != drm_vblank_count(dev, crtc),
1069 msecs_to_jiffies(100));
1073 drm_vblank_put(dev, crtc);
1075 EXPORT_SYMBOL(drm_wait_one_vblank);
1078 * drm_crtc_wait_one_vblank - wait for one vblank
1081 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1082 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1083 * due to lack of driver support or because the crtc is off.
1085 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1087 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1089 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1092 * drm_vblank_off - disable vblank events on a CRTC
1094 * @crtc: CRTC in question
1096 * Drivers can use this function to shut down the vblank interrupt handling when
1097 * disabling a crtc. This function ensures that the latest vblank frame count is
1098 * stored so that drm_vblank_on() can restore it again.
1100 * Drivers must use this function when the hardware vblank counter can get
1101 * reset, e.g. when suspending.
1103 * This is the legacy version of drm_crtc_vblank_off().
1105 void drm_vblank_off(struct drm_device *dev, int crtc)
1107 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1108 struct drm_pending_vblank_event *e, *t;
1110 unsigned long irqflags;
1113 if (WARN_ON(crtc >= dev->num_crtcs))
1116 spin_lock_irqsave(&dev->event_lock, irqflags);
1118 spin_lock(&dev->vbl_lock);
1119 vblank_disable_and_save(dev, crtc);
1120 wake_up(&vblank->queue);
1123 * Prevent subsequent drm_vblank_get() from re-enabling
1124 * the vblank interrupt by bumping the refcount.
1126 if (!vblank->inmodeset) {
1127 atomic_inc(&vblank->refcount);
1128 vblank->inmodeset = 1;
1130 spin_unlock(&dev->vbl_lock);
1132 /* Send any queued vblank events, lest the natives grow disquiet */
1133 seq = drm_vblank_count_and_time(dev, crtc, &now);
1135 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1136 if (e->pipe != crtc)
1138 DRM_DEBUG("Sending premature vblank event on disable: \
1139 wanted %d, current %d\n",
1140 e->event.sequence, seq);
1141 list_del(&e->base.link);
1142 drm_vblank_put(dev, e->pipe);
1143 send_vblank_event(dev, e, seq, &now);
1145 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1147 EXPORT_SYMBOL(drm_vblank_off);
1150 * drm_crtc_vblank_off - disable vblank events on a CRTC
1151 * @crtc: CRTC in question
1153 * Drivers can use this function to shut down the vblank interrupt handling when
1154 * disabling a crtc. This function ensures that the latest vblank frame count is
1155 * stored so that drm_vblank_on can restore it again.
1157 * Drivers must use this function when the hardware vblank counter can get
1158 * reset, e.g. when suspending.
1160 * This is the native kms version of drm_vblank_off().
1162 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1164 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1166 EXPORT_SYMBOL(drm_crtc_vblank_off);
1169 * drm_vblank_on - enable vblank events on a CRTC
1171 * @crtc: CRTC in question
1173 * This functions restores the vblank interrupt state captured with
1174 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1175 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1176 * in driver load code to reflect the current hardware state of the crtc.
1178 * This is the legacy version of drm_crtc_vblank_on().
1180 void drm_vblank_on(struct drm_device *dev, int crtc)
1182 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1183 unsigned long irqflags;
1185 if (WARN_ON(crtc >= dev->num_crtcs))
1188 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1189 /* Drop our private "prevent drm_vblank_get" refcount */
1190 if (vblank->inmodeset) {
1191 atomic_dec(&vblank->refcount);
1192 vblank->inmodeset = 0;
1196 * sample the current counter to avoid random jumps
1197 * when drm_vblank_enable() applies the diff
1199 * -1 to make sure user will never see the same
1200 * vblank counter value before and after a modeset
1203 (dev->driver->get_vblank_counter(dev, crtc) - 1) &
1204 dev->max_vblank_count;
1206 * re-enable interrupts if there are users left, or the
1207 * user wishes vblank interrupts to be enabled all the time.
1209 if (atomic_read(&vblank->refcount) != 0 ||
1210 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1211 WARN_ON(drm_vblank_enable(dev, crtc));
1212 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1214 EXPORT_SYMBOL(drm_vblank_on);
1217 * drm_crtc_vblank_on - enable vblank events on a CRTC
1218 * @crtc: CRTC in question
1220 * This functions restores the vblank interrupt state captured with
1221 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1222 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1223 * in driver load code to reflect the current hardware state of the crtc.
1225 * This is the native kms version of drm_vblank_on().
1227 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1229 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1231 EXPORT_SYMBOL(drm_crtc_vblank_on);
1234 * drm_vblank_pre_modeset - account for vblanks across mode sets
1236 * @crtc: CRTC in question
1238 * Account for vblank events across mode setting events, which will likely
1239 * reset the hardware frame counter.
1241 * This is done by grabbing a temporary vblank reference to ensure that the
1242 * vblank interrupt keeps running across the modeset sequence. With this the
1243 * software-side vblank frame counting will ensure that there are no jumps or
1246 * Unfortunately this approach is racy and also doesn't work when the vblank
1247 * interrupt stops running, e.g. across system suspend resume. It is therefore
1248 * highly recommended that drivers use the newer drm_vblank_off() and
1249 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1250 * using "cooked" software vblank frame counters and not relying on any hardware
1253 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1256 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1258 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1260 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1261 if (!dev->num_crtcs)
1264 if (WARN_ON(crtc >= dev->num_crtcs))
1268 * To avoid all the problems that might happen if interrupts
1269 * were enabled/disabled around or between these calls, we just
1270 * have the kernel take a reference on the CRTC (just once though
1271 * to avoid corrupting the count if multiple, mismatch calls occur),
1272 * so that interrupts remain enabled in the interim.
1274 if (!vblank->inmodeset) {
1275 vblank->inmodeset = 0x1;
1276 if (drm_vblank_get(dev, crtc) == 0)
1277 vblank->inmodeset |= 0x2;
1280 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1283 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1285 * @crtc: CRTC in question
1287 * This function again drops the temporary vblank reference acquired in
1288 * drm_vblank_pre_modeset.
1290 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1292 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1293 unsigned long irqflags;
1295 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1296 if (!dev->num_crtcs)
1299 if (vblank->inmodeset) {
1300 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1301 dev->vblank_disable_allowed = true;
1302 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1304 if (vblank->inmodeset & 0x2)
1305 drm_vblank_put(dev, crtc);
1307 vblank->inmodeset = 0;
1310 EXPORT_SYMBOL(drm_vblank_post_modeset);
1313 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1314 * @DRM_IOCTL_ARGS: standard ioctl arguments
1316 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1317 * ioctls around modesetting so that any lost vblank events are accounted for.
1319 * Generally the counter will reset across mode sets. If interrupts are
1320 * enabled around this call, we don't have to do anything since the counter
1321 * will have already been incremented.
1323 int drm_modeset_ctl(struct drm_device *dev, void *data,
1324 struct drm_file *file_priv)
1326 struct drm_modeset_ctl *modeset = data;
1329 /* If drm_vblank_init() hasn't been called yet, just no-op */
1330 if (!dev->num_crtcs)
1333 /* KMS drivers handle this internally */
1334 if (drm_core_check_feature(dev, DRIVER_MODESET))
1337 crtc = modeset->crtc;
1338 if (crtc >= dev->num_crtcs)
1341 switch (modeset->cmd) {
1342 case _DRM_PRE_MODESET:
1343 drm_vblank_pre_modeset(dev, crtc);
1345 case _DRM_POST_MODESET:
1346 drm_vblank_post_modeset(dev, crtc);
1355 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1356 union drm_wait_vblank *vblwait,
1357 struct drm_file *file_priv)
1359 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1360 struct drm_pending_vblank_event *e;
1362 unsigned long flags;
1366 e = kzalloc(sizeof *e, GFP_KERNEL);
1373 e->base.pid = current->pid;
1374 e->event.base.type = DRM_EVENT_VBLANK;
1375 e->event.base.length = sizeof e->event;
1376 e->event.user_data = vblwait->request.signal;
1377 e->base.event = &e->event.base;
1378 e->base.file_priv = file_priv;
1379 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1381 spin_lock_irqsave(&dev->event_lock, flags);
1384 * drm_vblank_off() might have been called after we called
1385 * drm_vblank_get(). drm_vblank_off() holds event_lock
1386 * around the vblank disable, so no need for further locking.
1387 * The reference from drm_vblank_get() protects against
1388 * vblank disable from another source.
1390 if (!vblank->enabled) {
1395 if (file_priv->event_space < sizeof e->event) {
1400 file_priv->event_space -= sizeof e->event;
1401 seq = drm_vblank_count_and_time(dev, pipe, &now);
1403 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1404 (seq - vblwait->request.sequence) <= (1 << 23)) {
1405 vblwait->request.sequence = seq + 1;
1406 vblwait->reply.sequence = vblwait->request.sequence;
1409 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1410 vblwait->request.sequence, seq, pipe);
1412 trace_drm_vblank_event_queued(current->pid, pipe,
1413 vblwait->request.sequence);
1415 e->event.sequence = vblwait->request.sequence;
1416 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1417 drm_vblank_put(dev, pipe);
1418 send_vblank_event(dev, e, seq, &now);
1419 vblwait->reply.sequence = seq;
1421 /* drm_handle_vblank_events will call drm_vblank_put */
1422 list_add_tail(&e->base.link, &dev->vblank_event_list);
1423 vblwait->reply.sequence = vblwait->request.sequence;
1426 spin_unlock_irqrestore(&dev->event_lock, flags);
1431 spin_unlock_irqrestore(&dev->event_lock, flags);
1434 drm_vblank_put(dev, pipe);
1441 * \param inode device inode.
1442 * \param file_priv DRM file private.
1443 * \param cmd command.
1444 * \param data user argument, pointing to a drm_wait_vblank structure.
1445 * \return zero on success or a negative number on failure.
1447 * This function enables the vblank interrupt on the pipe requested, then
1448 * sleeps waiting for the requested sequence number to occur, and drops
1449 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1450 * after a timeout with no further vblank waits scheduled).
1452 int drm_wait_vblank(struct drm_device *dev, void *data,
1453 struct drm_file *file_priv)
1455 struct drm_vblank_crtc *vblank;
1456 union drm_wait_vblank *vblwait = data;
1458 unsigned int flags, seq, crtc, high_crtc;
1460 if (!dev->irq_enabled)
1463 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1466 if (vblwait->request.type &
1467 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1468 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1469 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1470 vblwait->request.type,
1471 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1472 _DRM_VBLANK_HIGH_CRTC_MASK));
1476 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1477 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1479 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1481 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1482 if (crtc >= dev->num_crtcs)
1485 vblank = &dev->vblank[crtc];
1487 ret = drm_vblank_get(dev, crtc);
1489 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1492 seq = drm_vblank_count(dev, crtc);
1494 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1495 case _DRM_VBLANK_RELATIVE:
1496 vblwait->request.sequence += seq;
1497 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1498 case _DRM_VBLANK_ABSOLUTE:
1505 if (flags & _DRM_VBLANK_EVENT) {
1506 /* must hold on to the vblank ref until the event fires
1507 * drm_vblank_put will be called asynchronously
1509 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1512 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1513 (seq - vblwait->request.sequence) <= (1<<23)) {
1514 vblwait->request.sequence = seq + 1;
1517 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1518 vblwait->request.sequence, crtc);
1519 vblank->last_wait = vblwait->request.sequence;
1520 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1521 (((drm_vblank_count(dev, crtc) -
1522 vblwait->request.sequence) <= (1 << 23)) ||
1524 !dev->irq_enabled));
1526 if (ret != -EINTR) {
1529 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1530 vblwait->reply.tval_sec = now.tv_sec;
1531 vblwait->reply.tval_usec = now.tv_usec;
1533 DRM_DEBUG("returning %d to client\n",
1534 vblwait->reply.sequence);
1536 DRM_DEBUG("vblank wait interrupted by signal\n");
1540 drm_vblank_put(dev, crtc);
1544 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1546 struct drm_pending_vblank_event *e, *t;
1550 assert_spin_locked(&dev->event_lock);
1552 seq = drm_vblank_count_and_time(dev, crtc, &now);
1554 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1555 if (e->pipe != crtc)
1557 if ((seq - e->event.sequence) > (1<<23))
1560 DRM_DEBUG("vblank event on %d, current %d\n",
1561 e->event.sequence, seq);
1563 list_del(&e->base.link);
1564 drm_vblank_put(dev, e->pipe);
1565 send_vblank_event(dev, e, seq, &now);
1568 trace_drm_vblank_event(crtc, seq);
1572 * drm_handle_vblank - handle a vblank event
1574 * @crtc: where this event occurred
1576 * Drivers should call this routine in their vblank interrupt handlers to
1577 * update the vblank counter and send any signals that may be pending.
1579 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1581 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1584 struct timeval tvblank;
1585 unsigned long irqflags;
1587 if (!dev->num_crtcs)
1590 if (WARN_ON(crtc >= dev->num_crtcs))
1593 spin_lock_irqsave(&dev->event_lock, irqflags);
1595 /* Need timestamp lock to prevent concurrent execution with
1596 * vblank enable/disable, as this would cause inconsistent
1597 * or corrupted timestamps and vblank counts.
1599 spin_lock(&dev->vblank_time_lock);
1601 /* Vblank irq handling disabled. Nothing to do. */
1602 if (!vblank->enabled) {
1603 spin_unlock(&dev->vblank_time_lock);
1604 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1608 /* Fetch corresponding timestamp for this vblank interval from
1609 * driver and store it in proper slot of timestamp ringbuffer.
1612 /* Get current timestamp and count. */
1613 vblcount = atomic_read(&vblank->count);
1614 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1616 /* Compute time difference to timestamp of last vblank */
1617 diff_ns = timeval_to_ns(&tvblank) -
1618 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1620 /* Update vblank timestamp and count if at least
1621 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1622 * difference between last stored timestamp and current
1623 * timestamp. A smaller difference means basically
1624 * identical timestamps. Happens if this vblank has
1625 * been already processed and this is a redundant call,
1626 * e.g., due to spurious vblank interrupts. We need to
1627 * ignore those for accounting.
1629 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1630 /* Store new timestamp in ringbuffer. */
1631 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1633 /* Increment cooked vblank count. This also atomically commits
1634 * the timestamp computed above.
1636 smp_mb__before_atomic();
1637 atomic_inc(&vblank->count);
1638 smp_mb__after_atomic();
1640 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1641 crtc, (int) diff_ns);
1644 spin_unlock(&dev->vblank_time_lock);
1646 wake_up(&vblank->queue);
1647 drm_handle_vblank_events(dev, crtc);
1649 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1653 EXPORT_SYMBOL(drm_handle_vblank);