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 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, crtc, count) \
47 ((dev)->vblank[crtc].time[(count) % DRM_VBLANKTIME_RBSIZE])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
61 struct timeval *tvblank, unsigned flags);
63 static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
66 * Default to use monotonic timestamps for wait-for-vblank and page-flip
69 unsigned int drm_timestamp_monotonic = 1;
71 static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
73 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
74 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
75 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
78 * drm_update_vblank_count - update the master vblank counter
80 * @crtc: counter to update
82 * Call back into the driver to update the appropriate vblank counter
83 * (specified by @crtc). Deal with wraparound, if it occurred, and
84 * update the last read value so we can deal with wraparound on the next
87 * Only necessary when going from off->on, to account for frames we
88 * didn't get an interrupt for.
90 * Note: caller must hold dev->vbl_lock since this reads & writes
91 * device vblank fields.
93 static void drm_update_vblank_count(struct drm_device *dev, int crtc)
95 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
96 u32 cur_vblank, diff, tslot;
98 struct timeval t_vblank;
101 * Interrupts were disabled prior to this call, so deal with counter
103 * NOTE! It's possible we lost a full dev->max_vblank_count events
104 * here if the register is small or we had vblank interrupts off for
107 * We repeat the hardware vblank counter & timestamp query until
108 * we get consistent results. This to prevent races between gpu
109 * updating its hardware counter while we are retrieving the
110 * corresponding vblank timestamp.
113 cur_vblank = dev->driver->get_vblank_counter(dev, crtc);
114 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0);
115 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc));
117 /* Deal with counter wrap */
118 diff = cur_vblank - vblank->last;
119 if (cur_vblank < vblank->last) {
120 diff += dev->max_vblank_count;
122 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
123 crtc, vblank->last, cur_vblank, diff);
126 DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
129 /* Reinitialize corresponding vblank timestamp if high-precision query
130 * available. Skip this step if query unsupported or failed. Will
131 * reinitialize delayed at next vblank interrupt in that case.
134 tslot = atomic_read(&vblank->count) + diff;
135 vblanktimestamp(dev, crtc, tslot) = t_vblank;
138 smp_mb__before_atomic();
139 atomic_add(diff, &vblank->count);
140 smp_mb__after_atomic();
144 * Disable vblank irq's on crtc, make sure that last vblank count
145 * of hardware and corresponding consistent software vblank counter
146 * are preserved, even if there are any spurious vblank irq's after
149 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
151 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
152 unsigned long irqflags;
156 struct timeval tvblank;
157 int count = DRM_TIMESTAMP_MAXRETRIES;
159 /* Prevent vblank irq processing while disabling vblank irqs,
160 * so no updates of timestamps or count can happen after we've
161 * disabled. Needed to prevent races in case of delayed irq's.
163 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
166 * If the vblank interrupt was already disbled update the count
167 * and timestamp to maintain the appearance that the counter
168 * has been ticking all along until this time. This makes the
169 * count account for the entire time between drm_vblank_on() and
172 * But only do this if precise vblank timestamps are available.
173 * Otherwise we might read a totally bogus timestamp since drivers
174 * lacking precise timestamp support rely upon sampling the system clock
175 * at vblank interrupt time. Which obviously won't work out well if the
176 * vblank interrupt is disabled.
178 if (!vblank->enabled &&
179 drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0)) {
180 drm_update_vblank_count(dev, crtc);
181 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
185 dev->driver->disable_vblank(dev, crtc);
186 vblank->enabled = false;
188 /* No further vblank irq's will be processed after
189 * this point. Get current hardware vblank count and
190 * vblank timestamp, repeat until they are consistent.
192 * FIXME: There is still a race condition here and in
193 * drm_update_vblank_count() which can cause off-by-one
194 * reinitialization of software vblank counter. If gpu
195 * vblank counter doesn't increment exactly at the leading
196 * edge of a vblank interval, then we can lose 1 count if
197 * we happen to execute between start of vblank and the
198 * delayed gpu counter increment.
201 vblank->last = dev->driver->get_vblank_counter(dev, crtc);
202 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
203 } while (vblank->last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
208 /* Compute time difference to stored timestamp of last vblank
209 * as updated by last invocation of drm_handle_vblank() in vblank irq.
211 vblcount = atomic_read(&vblank->count);
212 diff_ns = timeval_to_ns(&tvblank) -
213 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
215 /* If there is at least 1 msec difference between the last stored
216 * timestamp and tvblank, then we are currently executing our
217 * disable inside a new vblank interval, the tvblank timestamp
218 * corresponds to this new vblank interval and the irq handler
219 * for this vblank didn't run yet and won't run due to our disable.
220 * Therefore we need to do the job of drm_handle_vblank() and
221 * increment the vblank counter by one to account for this vblank.
223 * Skip this step if there isn't any high precision timestamp
224 * available. In that case we can't account for this and just
227 if (vblrc && (abs64(diff_ns) > 1000000)) {
228 /* Store new timestamp in ringbuffer. */
229 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
231 /* Increment cooked vblank count. This also atomically commits
232 * the timestamp computed above.
234 smp_mb__before_atomic();
235 atomic_inc(&vblank->count);
236 smp_mb__after_atomic();
239 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
242 static void vblank_disable_fn(unsigned long arg)
244 struct drm_vblank_crtc *vblank = (void *)arg;
245 struct drm_device *dev = vblank->dev;
246 unsigned long irqflags;
247 int crtc = vblank->crtc;
249 if (!dev->vblank_disable_allowed)
252 spin_lock_irqsave(&dev->vbl_lock, irqflags);
253 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
254 DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
255 vblank_disable_and_save(dev, crtc);
257 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
261 * drm_vblank_cleanup - cleanup vblank support
264 * This function cleans up any resources allocated in drm_vblank_init.
266 void drm_vblank_cleanup(struct drm_device *dev)
269 unsigned long irqflags;
271 /* Bail if the driver didn't call drm_vblank_init() */
272 if (dev->num_crtcs == 0)
275 for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
276 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
278 del_timer_sync(&vblank->disable_timer);
280 spin_lock_irqsave(&dev->vbl_lock, irqflags);
281 vblank_disable_and_save(dev, crtc);
282 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
289 EXPORT_SYMBOL(drm_vblank_cleanup);
292 * drm_vblank_init - initialize vblank support
294 * @num_crtcs: number of crtcs supported by @dev
296 * This function initializes vblank support for @num_crtcs display pipelines.
299 * Zero on success or a negative error code on failure.
301 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
303 int i, ret = -ENOMEM;
305 spin_lock_init(&dev->vbl_lock);
306 spin_lock_init(&dev->vblank_time_lock);
308 dev->num_crtcs = num_crtcs;
310 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
314 for (i = 0; i < num_crtcs; i++) {
315 struct drm_vblank_crtc *vblank = &dev->vblank[i];
319 init_waitqueue_head(&vblank->queue);
320 setup_timer(&vblank->disable_timer, vblank_disable_fn,
321 (unsigned long)vblank);
324 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
326 /* Driver specific high-precision vblank timestamping supported? */
327 if (dev->driver->get_vblank_timestamp)
328 DRM_INFO("Driver supports precise vblank timestamp query.\n");
330 DRM_INFO("No driver support for vblank timestamp query.\n");
332 dev->vblank_disable_allowed = false;
340 EXPORT_SYMBOL(drm_vblank_init);
342 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
344 struct drm_device *dev = cookie;
346 if (dev->driver->vgaarb_irq) {
347 dev->driver->vgaarb_irq(dev, state);
351 if (!dev->irq_enabled)
355 if (dev->driver->irq_uninstall)
356 dev->driver->irq_uninstall(dev);
358 if (dev->driver->irq_preinstall)
359 dev->driver->irq_preinstall(dev);
360 if (dev->driver->irq_postinstall)
361 dev->driver->irq_postinstall(dev);
366 * drm_irq_install - install IRQ handler
368 * @irq: IRQ number to install the handler for
370 * Initializes the IRQ related data. Installs the handler, calling the driver
371 * irq_preinstall() and irq_postinstall() functions before and after the
374 * This is the simplified helper interface provided for drivers with no special
375 * needs. Drivers which need to install interrupt handlers for multiple
376 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
377 * that vblank interrupts are available.
380 * Zero on success or a negative error code on failure.
382 int drm_irq_install(struct drm_device *dev, int irq)
385 unsigned long sh_flags = 0;
387 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
393 /* Driver must have been initialized */
394 if (!dev->dev_private)
397 if (dev->irq_enabled)
399 dev->irq_enabled = true;
401 DRM_DEBUG("irq=%d\n", irq);
403 /* Before installing handler */
404 if (dev->driver->irq_preinstall)
405 dev->driver->irq_preinstall(dev);
407 /* Install handler */
408 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
409 sh_flags = IRQF_SHARED;
411 ret = request_irq(irq, dev->driver->irq_handler,
412 sh_flags, dev->driver->name, dev);
415 dev->irq_enabled = false;
419 if (!drm_core_check_feature(dev, DRIVER_MODESET))
420 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
422 /* After installing handler */
423 if (dev->driver->irq_postinstall)
424 ret = dev->driver->irq_postinstall(dev);
427 dev->irq_enabled = false;
428 if (!drm_core_check_feature(dev, DRIVER_MODESET))
429 vga_client_register(dev->pdev, NULL, NULL, NULL);
437 EXPORT_SYMBOL(drm_irq_install);
440 * drm_irq_uninstall - uninstall the IRQ handler
443 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
444 * This should only be called by drivers which used drm_irq_install() to set up
445 * their interrupt handler. Other drivers must only reset
446 * drm_device->irq_enabled to false.
448 * Note that for kernel modesetting drivers it is a bug if this function fails.
449 * The sanity checks are only to catch buggy user modesetting drivers which call
450 * the same function through an ioctl.
453 * Zero on success or a negative error code on failure.
455 int drm_irq_uninstall(struct drm_device *dev)
457 unsigned long irqflags;
461 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
464 irq_enabled = dev->irq_enabled;
465 dev->irq_enabled = false;
468 * Wake up any waiters so they don't hang.
470 if (dev->num_crtcs) {
471 spin_lock_irqsave(&dev->vbl_lock, irqflags);
472 for (i = 0; i < dev->num_crtcs; i++) {
473 struct drm_vblank_crtc *vblank = &dev->vblank[i];
475 wake_up(&vblank->queue);
476 vblank->enabled = false;
478 dev->driver->get_vblank_counter(dev, i);
480 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
486 DRM_DEBUG("irq=%d\n", dev->irq);
488 if (!drm_core_check_feature(dev, DRIVER_MODESET))
489 vga_client_register(dev->pdev, NULL, NULL, NULL);
491 if (dev->driver->irq_uninstall)
492 dev->driver->irq_uninstall(dev);
494 free_irq(dev->irq, dev);
498 EXPORT_SYMBOL(drm_irq_uninstall);
503 * \param inode device inode.
504 * \param file_priv DRM file private.
505 * \param cmd command.
506 * \param arg user argument, pointing to a drm_control structure.
507 * \return zero on success or a negative number on failure.
509 * Calls irq_install() or irq_uninstall() according to \p arg.
511 int drm_control(struct drm_device *dev, void *data,
512 struct drm_file *file_priv)
514 struct drm_control *ctl = data;
517 /* if we haven't irq we fallback for compatibility reasons -
518 * this used to be a separate function in drm_dma.h
521 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
523 if (drm_core_check_feature(dev, DRIVER_MODESET))
525 /* UMS was only ever support on pci devices. */
526 if (WARN_ON(!dev->pdev))
530 case DRM_INST_HANDLER:
531 irq = dev->pdev->irq;
533 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
536 mutex_lock(&dev->struct_mutex);
537 ret = drm_irq_install(dev, irq);
538 mutex_unlock(&dev->struct_mutex);
541 case DRM_UNINST_HANDLER:
542 mutex_lock(&dev->struct_mutex);
543 ret = drm_irq_uninstall(dev);
544 mutex_unlock(&dev->struct_mutex);
553 * drm_calc_timestamping_constants - calculate vblank timestamp constants
554 * @crtc: drm_crtc whose timestamp constants should be updated.
555 * @mode: display mode containing the scanout timings
557 * Calculate and store various constants which are later
558 * needed by vblank and swap-completion timestamping, e.g,
559 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
560 * derived from CRTC's true scanout timing, so they take
561 * things like panel scaling or other adjustments into account.
563 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
564 const struct drm_display_mode *mode)
566 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
567 int dotclock = mode->crtc_clock;
569 /* Valid dotclock? */
571 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
574 * Convert scanline length in pixels and video
575 * dot clock to line duration, frame duration
576 * and pixel duration in nanoseconds:
578 pixeldur_ns = 1000000 / dotclock;
579 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
580 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
583 * Fields of interlaced scanout modes are only half a frame duration.
585 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
588 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
591 crtc->pixeldur_ns = pixeldur_ns;
592 crtc->linedur_ns = linedur_ns;
593 crtc->framedur_ns = framedur_ns;
595 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
596 crtc->base.id, mode->crtc_htotal,
597 mode->crtc_vtotal, mode->crtc_vdisplay);
598 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
599 crtc->base.id, dotclock, framedur_ns,
600 linedur_ns, pixeldur_ns);
602 EXPORT_SYMBOL(drm_calc_timestamping_constants);
605 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
607 * @crtc: Which CRTC's vblank timestamp to retrieve
608 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
609 * On return contains true maximum error of timestamp
610 * @vblank_time: Pointer to struct timeval which should receive the timestamp
611 * @flags: Flags to pass to driver:
613 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
614 * @refcrtc: CRTC which defines scanout timing
615 * @mode: mode which defines the scanout timings
617 * Implements calculation of exact vblank timestamps from given drm_display_mode
618 * timings and current video scanout position of a CRTC. This can be called from
619 * within get_vblank_timestamp() implementation of a kms driver to implement the
620 * actual timestamping.
622 * Should return timestamps conforming to the OML_sync_control OpenML
623 * extension specification. The timestamp corresponds to the end of
624 * the vblank interval, aka start of scanout of topmost-leftmost display
625 * pixel in the following video frame.
627 * Requires support for optional dev->driver->get_scanout_position()
628 * in kms driver, plus a bit of setup code to provide a drm_display_mode
629 * that corresponds to the true scanout timing.
631 * The current implementation only handles standard video modes. It
632 * returns as no operation if a doublescan or interlaced video mode is
633 * active. Higher level code is expected to handle this.
636 * Negative value on error, failure or if not supported in current
639 * -EINVAL - Invalid CRTC.
640 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
641 * -ENOTSUPP - Function not supported in current display mode.
642 * -EIO - Failed, e.g., due to failed scanout position query.
644 * Returns or'ed positive status flags on success:
646 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
647 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
650 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
652 struct timeval *vblank_time,
654 const struct drm_crtc *refcrtc,
655 const struct drm_display_mode *mode)
657 struct timeval tv_etime;
658 ktime_t stime, etime;
661 int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
664 if (crtc < 0 || crtc >= dev->num_crtcs) {
665 DRM_ERROR("Invalid crtc %d\n", crtc);
669 /* Scanout position query not supported? Should not happen. */
670 if (!dev->driver->get_scanout_position) {
671 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
675 /* Durations of frames, lines, pixels in nanoseconds. */
676 framedur_ns = refcrtc->framedur_ns;
677 linedur_ns = refcrtc->linedur_ns;
678 pixeldur_ns = refcrtc->pixeldur_ns;
680 /* If mode timing undefined, just return as no-op:
681 * Happens during initial modesetting of a crtc.
683 if (framedur_ns == 0) {
684 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
688 /* Get current scanout position with system timestamp.
689 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
690 * if single query takes longer than max_error nanoseconds.
692 * This guarantees a tight bound on maximum error if
693 * code gets preempted or delayed for some reason.
695 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
697 * Get vertical and horizontal scanout position vpos, hpos,
698 * and bounding timestamps stime, etime, pre/post query.
700 vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
701 &hpos, &stime, &etime);
703 /* Return as no-op if scanout query unsupported or failed. */
704 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
705 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
710 /* Compute uncertainty in timestamp of scanout position query. */
711 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
713 /* Accept result with < max_error nsecs timing uncertainty. */
714 if (duration_ns <= *max_error)
718 /* Noisy system timing? */
719 if (i == DRM_TIMESTAMP_MAXRETRIES) {
720 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
721 crtc, duration_ns/1000, *max_error/1000, i);
724 /* Return upper bound of timestamp precision error. */
725 *max_error = duration_ns;
727 /* Check if in vblank area:
728 * vpos is >=0 in video scanout area, but negative
729 * within vblank area, counting down the number of lines until
732 invbl = vbl_status & DRM_SCANOUTPOS_IN_VBLANK;
734 /* Convert scanout position into elapsed time at raw_time query
735 * since start of scanout at first display scanline. delta_ns
736 * can be negative if start of scanout hasn't happened yet.
738 delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
740 if (!drm_timestamp_monotonic)
741 etime = ktime_mono_to_real(etime);
743 /* save this only for debugging purposes */
744 tv_etime = ktime_to_timeval(etime);
745 /* Subtract time delta from raw timestamp to get final
746 * vblank_time timestamp for end of vblank.
749 etime = ktime_add_ns(etime, -delta_ns);
751 etime = ktime_sub_ns(etime, delta_ns);
752 *vblank_time = ktime_to_timeval(etime);
754 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
755 crtc, (int)vbl_status, hpos, vpos,
756 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
757 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
758 duration_ns/1000, i);
760 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
762 vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
766 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
768 static struct timeval get_drm_timestamp(void)
772 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
773 return ktime_to_timeval(now);
777 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
780 * @crtc: which CRTC's vblank timestamp to retrieve
781 * @tvblank: Pointer to target struct timeval which should receive the timestamp
782 * @flags: Flags to pass to driver:
784 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
786 * Fetches the system timestamp corresponding to the time of the most recent
787 * vblank interval on specified CRTC. May call into kms-driver to
788 * compute the timestamp with a high-precision GPU specific method.
790 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
791 * call, i.e., it isn't very precisely locked to the true vblank.
794 * True if timestamp is considered to be very precise, false otherwise.
797 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
798 struct timeval *tvblank, unsigned flags)
802 /* Define requested maximum error on timestamps (nanoseconds). */
803 int max_error = (int) drm_timestamp_precision * 1000;
805 /* Query driver if possible and precision timestamping enabled. */
806 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
807 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
813 /* GPU high precision timestamp query unsupported or failed.
814 * Return current monotonic/gettimeofday timestamp as best estimate.
816 *tvblank = get_drm_timestamp();
822 * drm_vblank_count - retrieve "cooked" vblank counter value
824 * @crtc: which counter to retrieve
826 * Fetches the "cooked" vblank count value that represents the number of
827 * vblank events since the system was booted, including lost events due to
828 * modesetting activity.
831 * The software vblank counter.
833 u32 drm_vblank_count(struct drm_device *dev, int crtc)
835 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
837 if (WARN_ON(crtc >= dev->num_crtcs))
839 return atomic_read(&vblank->count);
841 EXPORT_SYMBOL(drm_vblank_count);
844 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
845 * and the system timestamp corresponding to that vblank counter value.
848 * @crtc: which counter to retrieve
849 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
851 * Fetches the "cooked" vblank count value that represents the number of
852 * vblank events since the system was booted, including lost events due to
853 * modesetting activity. Returns corresponding system timestamp of the time
854 * of the vblank interval that corresponds to the current vblank counter value.
856 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
857 struct timeval *vblanktime)
859 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
862 if (WARN_ON(crtc >= dev->num_crtcs))
865 /* Read timestamp from slot of _vblank_time ringbuffer
866 * that corresponds to current vblank count. Retry if
867 * count has incremented during readout. This works like
871 cur_vblank = atomic_read(&vblank->count);
872 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
874 } while (cur_vblank != atomic_read(&vblank->count));
878 EXPORT_SYMBOL(drm_vblank_count_and_time);
880 static void send_vblank_event(struct drm_device *dev,
881 struct drm_pending_vblank_event *e,
882 unsigned long seq, struct timeval *now)
884 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
885 e->event.sequence = seq;
886 e->event.tv_sec = now->tv_sec;
887 e->event.tv_usec = now->tv_usec;
889 list_add_tail(&e->base.link,
890 &e->base.file_priv->event_list);
891 wake_up_interruptible(&e->base.file_priv->event_wait);
892 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
897 * drm_send_vblank_event - helper to send vblank event after pageflip
899 * @crtc: CRTC in question
900 * @e: the event to send
902 * Updates sequence # and timestamp on event, and sends it to userspace.
903 * Caller must hold event lock.
905 void drm_send_vblank_event(struct drm_device *dev, int crtc,
906 struct drm_pending_vblank_event *e)
911 seq = drm_vblank_count_and_time(dev, crtc, &now);
915 now = get_drm_timestamp();
918 send_vblank_event(dev, e, seq, &now);
920 EXPORT_SYMBOL(drm_send_vblank_event);
923 * drm_vblank_enable - enable the vblank interrupt on a CRTC
925 * @crtc: CRTC in question
927 static int drm_vblank_enable(struct drm_device *dev, int crtc)
929 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
932 assert_spin_locked(&dev->vbl_lock);
934 spin_lock(&dev->vblank_time_lock);
936 if (!vblank->enabled) {
938 * Enable vblank irqs under vblank_time_lock protection.
939 * All vblank count & timestamp updates are held off
940 * until we are done reinitializing master counter and
941 * timestamps. Filtercode in drm_handle_vblank() will
942 * prevent double-accounting of same vblank interval.
944 ret = dev->driver->enable_vblank(dev, crtc);
945 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
947 atomic_dec(&vblank->refcount);
949 vblank->enabled = true;
950 drm_update_vblank_count(dev, crtc);
954 spin_unlock(&dev->vblank_time_lock);
960 * drm_vblank_get - get a reference count on vblank events
962 * @crtc: which CRTC to own
964 * Acquire a reference count on vblank events to avoid having them disabled
967 * This is the legacy version of drm_crtc_vblank_get().
970 * Zero on success, nonzero on failure.
972 int drm_vblank_get(struct drm_device *dev, int crtc)
974 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
975 unsigned long irqflags;
978 if (WARN_ON(crtc >= dev->num_crtcs))
981 spin_lock_irqsave(&dev->vbl_lock, irqflags);
982 /* Going from 0->1 means we have to enable interrupts again */
983 if (atomic_add_return(1, &vblank->refcount) == 1) {
984 ret = drm_vblank_enable(dev, crtc);
986 if (!vblank->enabled) {
987 atomic_dec(&vblank->refcount);
991 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
995 EXPORT_SYMBOL(drm_vblank_get);
998 * drm_crtc_vblank_get - get a reference count on vblank events
999 * @crtc: which CRTC to own
1001 * Acquire a reference count on vblank events to avoid having them disabled
1004 * This is the native kms version of drm_vblank_off().
1007 * Zero on success, nonzero on failure.
1009 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1011 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1013 EXPORT_SYMBOL(drm_crtc_vblank_get);
1016 * drm_vblank_put - give up ownership of vblank events
1018 * @crtc: which counter to give up
1020 * Release ownership of a given vblank counter, turning off interrupts
1021 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1023 * This is the legacy version of drm_crtc_vblank_put().
1025 void drm_vblank_put(struct drm_device *dev, int crtc)
1027 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1029 BUG_ON(atomic_read(&vblank->refcount) == 0);
1031 if (WARN_ON(crtc >= dev->num_crtcs))
1034 /* Last user schedules interrupt disable */
1035 if (atomic_dec_and_test(&vblank->refcount)) {
1036 if (drm_vblank_offdelay == 0)
1038 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1039 vblank_disable_fn((unsigned long)vblank);
1041 mod_timer(&vblank->disable_timer,
1042 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1045 EXPORT_SYMBOL(drm_vblank_put);
1048 * drm_crtc_vblank_put - give up ownership of vblank events
1049 * @crtc: which counter to give up
1051 * Release ownership of a given vblank counter, turning off interrupts
1052 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1054 * This is the native kms version of drm_vblank_put().
1056 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1058 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1060 EXPORT_SYMBOL(drm_crtc_vblank_put);
1063 * drm_wait_one_vblank - wait for one vblank
1067 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1068 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1069 * due to lack of driver support or because the crtc is off.
1071 void drm_wait_one_vblank(struct drm_device *dev, int crtc)
1076 ret = drm_vblank_get(dev, crtc);
1080 last = drm_vblank_count(dev, crtc);
1082 ret = wait_event_timeout(dev->vblank[crtc].queue,
1083 last != drm_vblank_count(dev, crtc),
1084 msecs_to_jiffies(100));
1088 drm_vblank_put(dev, crtc);
1090 EXPORT_SYMBOL(drm_wait_one_vblank);
1093 * drm_crtc_wait_one_vblank - wait for one vblank
1096 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1097 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1098 * due to lack of driver support or because the crtc is off.
1100 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1102 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1104 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1107 * drm_vblank_off - disable vblank events on a CRTC
1109 * @crtc: CRTC in question
1111 * Drivers can use this function to shut down the vblank interrupt handling when
1112 * disabling a crtc. This function ensures that the latest vblank frame count is
1113 * stored so that drm_vblank_on() can restore it again.
1115 * Drivers must use this function when the hardware vblank counter can get
1116 * reset, e.g. when suspending.
1118 * This is the legacy version of drm_crtc_vblank_off().
1120 void drm_vblank_off(struct drm_device *dev, int crtc)
1122 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1123 struct drm_pending_vblank_event *e, *t;
1125 unsigned long irqflags;
1128 if (WARN_ON(crtc >= dev->num_crtcs))
1131 spin_lock_irqsave(&dev->event_lock, irqflags);
1133 spin_lock(&dev->vbl_lock);
1134 vblank_disable_and_save(dev, crtc);
1135 wake_up(&vblank->queue);
1138 * Prevent subsequent drm_vblank_get() from re-enabling
1139 * the vblank interrupt by bumping the refcount.
1141 if (!vblank->inmodeset) {
1142 atomic_inc(&vblank->refcount);
1143 vblank->inmodeset = 1;
1145 spin_unlock(&dev->vbl_lock);
1147 /* Send any queued vblank events, lest the natives grow disquiet */
1148 seq = drm_vblank_count_and_time(dev, crtc, &now);
1150 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1151 if (e->pipe != crtc)
1153 DRM_DEBUG("Sending premature vblank event on disable: \
1154 wanted %d, current %d\n",
1155 e->event.sequence, seq);
1156 list_del(&e->base.link);
1157 drm_vblank_put(dev, e->pipe);
1158 send_vblank_event(dev, e, seq, &now);
1160 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1162 EXPORT_SYMBOL(drm_vblank_off);
1165 * drm_crtc_vblank_off - disable vblank events on a CRTC
1166 * @crtc: CRTC in question
1168 * Drivers can use this function to shut down the vblank interrupt handling when
1169 * disabling a crtc. This function ensures that the latest vblank frame count is
1170 * stored so that drm_vblank_on can restore it again.
1172 * Drivers must use this function when the hardware vblank counter can get
1173 * reset, e.g. when suspending.
1175 * This is the native kms version of drm_vblank_off().
1177 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1179 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1181 EXPORT_SYMBOL(drm_crtc_vblank_off);
1184 * drm_vblank_on - enable vblank events on a CRTC
1186 * @crtc: CRTC in question
1188 * This functions restores the vblank interrupt state captured with
1189 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1190 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1191 * in driver load code to reflect the current hardware state of the crtc.
1193 * This is the legacy version of drm_crtc_vblank_on().
1195 void drm_vblank_on(struct drm_device *dev, int crtc)
1197 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1198 unsigned long irqflags;
1200 if (WARN_ON(crtc >= dev->num_crtcs))
1203 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1204 /* Drop our private "prevent drm_vblank_get" refcount */
1205 if (vblank->inmodeset) {
1206 atomic_dec(&vblank->refcount);
1207 vblank->inmodeset = 0;
1211 * sample the current counter to avoid random jumps
1212 * when drm_vblank_enable() applies the diff
1214 * -1 to make sure user will never see the same
1215 * vblank counter value before and after a modeset
1218 (dev->driver->get_vblank_counter(dev, crtc) - 1) &
1219 dev->max_vblank_count;
1221 * re-enable interrupts if there are users left, or the
1222 * user wishes vblank interrupts to be enabled all the time.
1224 if (atomic_read(&vblank->refcount) != 0 ||
1225 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1226 WARN_ON(drm_vblank_enable(dev, crtc));
1227 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1229 EXPORT_SYMBOL(drm_vblank_on);
1232 * drm_crtc_vblank_on - enable vblank events on a CRTC
1233 * @crtc: CRTC in question
1235 * This functions restores the vblank interrupt state captured with
1236 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1237 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1238 * in driver load code to reflect the current hardware state of the crtc.
1240 * This is the native kms version of drm_vblank_on().
1242 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1244 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1246 EXPORT_SYMBOL(drm_crtc_vblank_on);
1249 * drm_vblank_pre_modeset - account for vblanks across mode sets
1251 * @crtc: CRTC in question
1253 * Account for vblank events across mode setting events, which will likely
1254 * reset the hardware frame counter.
1256 * This is done by grabbing a temporary vblank reference to ensure that the
1257 * vblank interrupt keeps running across the modeset sequence. With this the
1258 * software-side vblank frame counting will ensure that there are no jumps or
1261 * Unfortunately this approach is racy and also doesn't work when the vblank
1262 * interrupt stops running, e.g. across system suspend resume. It is therefore
1263 * highly recommended that drivers use the newer drm_vblank_off() and
1264 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1265 * using "cooked" software vblank frame counters and not relying on any hardware
1268 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1271 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1273 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1275 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1276 if (!dev->num_crtcs)
1279 if (WARN_ON(crtc >= dev->num_crtcs))
1283 * To avoid all the problems that might happen if interrupts
1284 * were enabled/disabled around or between these calls, we just
1285 * have the kernel take a reference on the CRTC (just once though
1286 * to avoid corrupting the count if multiple, mismatch calls occur),
1287 * so that interrupts remain enabled in the interim.
1289 if (!vblank->inmodeset) {
1290 vblank->inmodeset = 0x1;
1291 if (drm_vblank_get(dev, crtc) == 0)
1292 vblank->inmodeset |= 0x2;
1295 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1298 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1300 * @crtc: CRTC in question
1302 * This function again drops the temporary vblank reference acquired in
1303 * drm_vblank_pre_modeset.
1305 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1307 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1308 unsigned long irqflags;
1310 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1311 if (!dev->num_crtcs)
1314 if (vblank->inmodeset) {
1315 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1316 dev->vblank_disable_allowed = true;
1317 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1319 if (vblank->inmodeset & 0x2)
1320 drm_vblank_put(dev, crtc);
1322 vblank->inmodeset = 0;
1325 EXPORT_SYMBOL(drm_vblank_post_modeset);
1328 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1329 * @DRM_IOCTL_ARGS: standard ioctl arguments
1331 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1332 * ioctls around modesetting so that any lost vblank events are accounted for.
1334 * Generally the counter will reset across mode sets. If interrupts are
1335 * enabled around this call, we don't have to do anything since the counter
1336 * will have already been incremented.
1338 int drm_modeset_ctl(struct drm_device *dev, void *data,
1339 struct drm_file *file_priv)
1341 struct drm_modeset_ctl *modeset = data;
1344 /* If drm_vblank_init() hasn't been called yet, just no-op */
1345 if (!dev->num_crtcs)
1348 /* KMS drivers handle this internally */
1349 if (drm_core_check_feature(dev, DRIVER_MODESET))
1352 crtc = modeset->crtc;
1353 if (crtc >= dev->num_crtcs)
1356 switch (modeset->cmd) {
1357 case _DRM_PRE_MODESET:
1358 drm_vblank_pre_modeset(dev, crtc);
1360 case _DRM_POST_MODESET:
1361 drm_vblank_post_modeset(dev, crtc);
1370 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1371 union drm_wait_vblank *vblwait,
1372 struct drm_file *file_priv)
1374 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1375 struct drm_pending_vblank_event *e;
1377 unsigned long flags;
1381 e = kzalloc(sizeof *e, GFP_KERNEL);
1388 e->base.pid = current->pid;
1389 e->event.base.type = DRM_EVENT_VBLANK;
1390 e->event.base.length = sizeof e->event;
1391 e->event.user_data = vblwait->request.signal;
1392 e->base.event = &e->event.base;
1393 e->base.file_priv = file_priv;
1394 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1396 spin_lock_irqsave(&dev->event_lock, flags);
1399 * drm_vblank_off() might have been called after we called
1400 * drm_vblank_get(). drm_vblank_off() holds event_lock
1401 * around the vblank disable, so no need for further locking.
1402 * The reference from drm_vblank_get() protects against
1403 * vblank disable from another source.
1405 if (!vblank->enabled) {
1410 if (file_priv->event_space < sizeof e->event) {
1415 file_priv->event_space -= sizeof e->event;
1416 seq = drm_vblank_count_and_time(dev, pipe, &now);
1418 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1419 (seq - vblwait->request.sequence) <= (1 << 23)) {
1420 vblwait->request.sequence = seq + 1;
1421 vblwait->reply.sequence = vblwait->request.sequence;
1424 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1425 vblwait->request.sequence, seq, pipe);
1427 trace_drm_vblank_event_queued(current->pid, pipe,
1428 vblwait->request.sequence);
1430 e->event.sequence = vblwait->request.sequence;
1431 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1432 drm_vblank_put(dev, pipe);
1433 send_vblank_event(dev, e, seq, &now);
1434 vblwait->reply.sequence = seq;
1436 /* drm_handle_vblank_events will call drm_vblank_put */
1437 list_add_tail(&e->base.link, &dev->vblank_event_list);
1438 vblwait->reply.sequence = vblwait->request.sequence;
1441 spin_unlock_irqrestore(&dev->event_lock, flags);
1446 spin_unlock_irqrestore(&dev->event_lock, flags);
1449 drm_vblank_put(dev, pipe);
1456 * \param inode device inode.
1457 * \param file_priv DRM file private.
1458 * \param cmd command.
1459 * \param data user argument, pointing to a drm_wait_vblank structure.
1460 * \return zero on success or a negative number on failure.
1462 * This function enables the vblank interrupt on the pipe requested, then
1463 * sleeps waiting for the requested sequence number to occur, and drops
1464 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1465 * after a timeout with no further vblank waits scheduled).
1467 int drm_wait_vblank(struct drm_device *dev, void *data,
1468 struct drm_file *file_priv)
1470 struct drm_vblank_crtc *vblank;
1471 union drm_wait_vblank *vblwait = data;
1473 unsigned int flags, seq, crtc, high_crtc;
1475 if (!dev->irq_enabled)
1478 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1481 if (vblwait->request.type &
1482 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1483 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1484 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1485 vblwait->request.type,
1486 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1487 _DRM_VBLANK_HIGH_CRTC_MASK));
1491 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1492 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1494 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1496 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1497 if (crtc >= dev->num_crtcs)
1500 vblank = &dev->vblank[crtc];
1502 ret = drm_vblank_get(dev, crtc);
1504 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1507 seq = drm_vblank_count(dev, crtc);
1509 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1510 case _DRM_VBLANK_RELATIVE:
1511 vblwait->request.sequence += seq;
1512 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1513 case _DRM_VBLANK_ABSOLUTE:
1520 if (flags & _DRM_VBLANK_EVENT) {
1521 /* must hold on to the vblank ref until the event fires
1522 * drm_vblank_put will be called asynchronously
1524 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1527 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1528 (seq - vblwait->request.sequence) <= (1<<23)) {
1529 vblwait->request.sequence = seq + 1;
1532 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1533 vblwait->request.sequence, crtc);
1534 vblank->last_wait = vblwait->request.sequence;
1535 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1536 (((drm_vblank_count(dev, crtc) -
1537 vblwait->request.sequence) <= (1 << 23)) ||
1539 !dev->irq_enabled));
1541 if (ret != -EINTR) {
1544 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1545 vblwait->reply.tval_sec = now.tv_sec;
1546 vblwait->reply.tval_usec = now.tv_usec;
1548 DRM_DEBUG("returning %d to client\n",
1549 vblwait->reply.sequence);
1551 DRM_DEBUG("vblank wait interrupted by signal\n");
1555 drm_vblank_put(dev, crtc);
1559 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1561 struct drm_pending_vblank_event *e, *t;
1565 assert_spin_locked(&dev->event_lock);
1567 seq = drm_vblank_count_and_time(dev, crtc, &now);
1569 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1570 if (e->pipe != crtc)
1572 if ((seq - e->event.sequence) > (1<<23))
1575 DRM_DEBUG("vblank event on %d, current %d\n",
1576 e->event.sequence, seq);
1578 list_del(&e->base.link);
1579 drm_vblank_put(dev, e->pipe);
1580 send_vblank_event(dev, e, seq, &now);
1583 trace_drm_vblank_event(crtc, seq);
1587 * drm_handle_vblank - handle a vblank event
1589 * @crtc: where this event occurred
1591 * Drivers should call this routine in their vblank interrupt handlers to
1592 * update the vblank counter and send any signals that may be pending.
1594 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1596 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1599 struct timeval tvblank;
1600 unsigned long irqflags;
1602 if (!dev->num_crtcs)
1605 if (WARN_ON(crtc >= dev->num_crtcs))
1608 spin_lock_irqsave(&dev->event_lock, irqflags);
1610 /* Need timestamp lock to prevent concurrent execution with
1611 * vblank enable/disable, as this would cause inconsistent
1612 * or corrupted timestamps and vblank counts.
1614 spin_lock(&dev->vblank_time_lock);
1616 /* Vblank irq handling disabled. Nothing to do. */
1617 if (!vblank->enabled) {
1618 spin_unlock(&dev->vblank_time_lock);
1619 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1623 /* Fetch corresponding timestamp for this vblank interval from
1624 * driver and store it in proper slot of timestamp ringbuffer.
1627 /* Get current timestamp and count. */
1628 vblcount = atomic_read(&vblank->count);
1629 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1631 /* Compute time difference to timestamp of last vblank */
1632 diff_ns = timeval_to_ns(&tvblank) -
1633 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1635 /* Update vblank timestamp and count if at least
1636 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1637 * difference between last stored timestamp and current
1638 * timestamp. A smaller difference means basically
1639 * identical timestamps. Happens if this vblank has
1640 * been already processed and this is a redundant call,
1641 * e.g., due to spurious vblank interrupts. We need to
1642 * ignore those for accounting.
1644 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1645 /* Store new timestamp in ringbuffer. */
1646 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1648 /* Increment cooked vblank count. This also atomically commits
1649 * the timestamp computed above.
1651 smp_mb__before_atomic();
1652 atomic_inc(&vblank->count);
1653 smp_mb__after_atomic();
1655 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1656 crtc, (int) diff_ns);
1659 spin_unlock(&dev->vblank_time_lock);
1661 wake_up(&vblank->queue);
1662 drm_handle_vblank_events(dev, crtc);
1664 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1668 EXPORT_SYMBOL(drm_handle_vblank);