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",
132 /* Reinitialize corresponding vblank timestamp if high-precision query
133 * available. Skip this step if query unsupported or failed. Will
134 * reinitialize delayed at next vblank interrupt in that case and
135 * assign 0 for now, to mark the vblanktimestamp as invalid.
137 tslot = atomic_read(&vblank->count) + diff;
138 vblanktimestamp(dev, crtc, tslot) = rc ? t_vblank : (struct timeval) {0, 0};
140 smp_mb__before_atomic();
141 atomic_add(diff, &vblank->count);
142 smp_mb__after_atomic();
146 * Disable vblank irq's on crtc, make sure that last vblank count
147 * of hardware and corresponding consistent software vblank counter
148 * are preserved, even if there are any spurious vblank irq's after
151 static void vblank_disable_and_save(struct drm_device *dev, int crtc)
153 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
154 unsigned long irqflags;
158 struct timeval tvblank;
159 int count = DRM_TIMESTAMP_MAXRETRIES;
161 /* Prevent vblank irq processing while disabling vblank irqs,
162 * so no updates of timestamps or count can happen after we've
163 * disabled. Needed to prevent races in case of delayed irq's.
165 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
168 * If the vblank interrupt was already disabled update the count
169 * and timestamp to maintain the appearance that the counter
170 * has been ticking all along until this time. This makes the
171 * count account for the entire time between drm_vblank_on() and
174 * But only do this if precise vblank timestamps are available.
175 * Otherwise we might read a totally bogus timestamp since drivers
176 * lacking precise timestamp support rely upon sampling the system clock
177 * at vblank interrupt time. Which obviously won't work out well if the
178 * vblank interrupt is disabled.
180 if (!vblank->enabled &&
181 drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0)) {
182 drm_update_vblank_count(dev, crtc);
183 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
188 * Only disable vblank interrupts if they're enabled. This avoids
189 * calling the ->disable_vblank() operation in atomic context with the
190 * hardware potentially runtime suspended.
192 if (vblank->enabled) {
193 dev->driver->disable_vblank(dev, crtc);
194 vblank->enabled = false;
197 /* No further vblank irq's will be processed after
198 * this point. Get current hardware vblank count and
199 * vblank timestamp, repeat until they are consistent.
201 * FIXME: There is still a race condition here and in
202 * drm_update_vblank_count() which can cause off-by-one
203 * reinitialization of software vblank counter. If gpu
204 * vblank counter doesn't increment exactly at the leading
205 * edge of a vblank interval, then we can lose 1 count if
206 * we happen to execute between start of vblank and the
207 * delayed gpu counter increment.
210 vblank->last = dev->driver->get_vblank_counter(dev, crtc);
211 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0);
212 } while (vblank->last != dev->driver->get_vblank_counter(dev, crtc) && (--count) && vblrc);
217 /* Compute time difference to stored timestamp of last vblank
218 * as updated by last invocation of drm_handle_vblank() in vblank irq.
220 vblcount = atomic_read(&vblank->count);
221 diff_ns = timeval_to_ns(&tvblank) -
222 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
224 /* If there is at least 1 msec difference between the last stored
225 * timestamp and tvblank, then we are currently executing our
226 * disable inside a new vblank interval, the tvblank timestamp
227 * corresponds to this new vblank interval and the irq handler
228 * for this vblank didn't run yet and won't run due to our disable.
229 * Therefore we need to do the job of drm_handle_vblank() and
230 * increment the vblank counter by one to account for this vblank.
232 * Skip this step if there isn't any high precision timestamp
233 * available. In that case we can't account for this and just
236 if (vblrc && (abs64(diff_ns) > 1000000)) {
237 /* Store new timestamp in ringbuffer. */
238 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
240 /* Increment cooked vblank count. This also atomically commits
241 * the timestamp computed above.
243 smp_mb__before_atomic();
244 atomic_inc(&vblank->count);
245 smp_mb__after_atomic();
248 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
251 static void vblank_disable_fn(unsigned long arg)
253 struct drm_vblank_crtc *vblank = (void *)arg;
254 struct drm_device *dev = vblank->dev;
255 unsigned long irqflags;
256 int crtc = vblank->crtc;
258 if (!dev->vblank_disable_allowed)
261 spin_lock_irqsave(&dev->vbl_lock, irqflags);
262 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
263 DRM_DEBUG("disabling vblank on crtc %d\n", crtc);
264 vblank_disable_and_save(dev, crtc);
266 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
270 * drm_vblank_cleanup - cleanup vblank support
273 * This function cleans up any resources allocated in drm_vblank_init.
275 void drm_vblank_cleanup(struct drm_device *dev)
279 /* Bail if the driver didn't call drm_vblank_init() */
280 if (dev->num_crtcs == 0)
283 for (crtc = 0; crtc < dev->num_crtcs; crtc++) {
284 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
286 WARN_ON(vblank->enabled &&
287 drm_core_check_feature(dev, DRIVER_MODESET));
289 del_timer_sync(&vblank->disable_timer);
296 EXPORT_SYMBOL(drm_vblank_cleanup);
299 * drm_vblank_init - initialize vblank support
301 * @num_crtcs: number of crtcs supported by @dev
303 * This function initializes vblank support for @num_crtcs display pipelines.
306 * Zero on success or a negative error code on failure.
308 int drm_vblank_init(struct drm_device *dev, int num_crtcs)
310 int i, ret = -ENOMEM;
312 spin_lock_init(&dev->vbl_lock);
313 spin_lock_init(&dev->vblank_time_lock);
315 dev->num_crtcs = num_crtcs;
317 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
321 for (i = 0; i < num_crtcs; i++) {
322 struct drm_vblank_crtc *vblank = &dev->vblank[i];
326 init_waitqueue_head(&vblank->queue);
327 setup_timer(&vblank->disable_timer, vblank_disable_fn,
328 (unsigned long)vblank);
331 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
333 /* Driver specific high-precision vblank timestamping supported? */
334 if (dev->driver->get_vblank_timestamp)
335 DRM_INFO("Driver supports precise vblank timestamp query.\n");
337 DRM_INFO("No driver support for vblank timestamp query.\n");
339 dev->vblank_disable_allowed = false;
347 EXPORT_SYMBOL(drm_vblank_init);
349 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
351 struct drm_device *dev = cookie;
353 if (dev->driver->vgaarb_irq) {
354 dev->driver->vgaarb_irq(dev, state);
358 if (!dev->irq_enabled)
362 if (dev->driver->irq_uninstall)
363 dev->driver->irq_uninstall(dev);
365 if (dev->driver->irq_preinstall)
366 dev->driver->irq_preinstall(dev);
367 if (dev->driver->irq_postinstall)
368 dev->driver->irq_postinstall(dev);
373 * drm_irq_install - install IRQ handler
375 * @irq: IRQ number to install the handler for
377 * Initializes the IRQ related data. Installs the handler, calling the driver
378 * irq_preinstall() and irq_postinstall() functions before and after the
381 * This is the simplified helper interface provided for drivers with no special
382 * needs. Drivers which need to install interrupt handlers for multiple
383 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
384 * that vblank interrupts are available.
387 * Zero on success or a negative error code on failure.
389 int drm_irq_install(struct drm_device *dev, int irq)
392 unsigned long sh_flags = 0;
394 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
400 /* Driver must have been initialized */
401 if (!dev->dev_private)
404 if (dev->irq_enabled)
406 dev->irq_enabled = true;
408 DRM_DEBUG("irq=%d\n", irq);
410 /* Before installing handler */
411 if (dev->driver->irq_preinstall)
412 dev->driver->irq_preinstall(dev);
414 /* Install handler */
415 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
416 sh_flags = IRQF_SHARED;
418 ret = request_irq(irq, dev->driver->irq_handler,
419 sh_flags, dev->driver->name, dev);
422 dev->irq_enabled = false;
426 if (!drm_core_check_feature(dev, DRIVER_MODESET))
427 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
429 /* After installing handler */
430 if (dev->driver->irq_postinstall)
431 ret = dev->driver->irq_postinstall(dev);
434 dev->irq_enabled = false;
435 if (!drm_core_check_feature(dev, DRIVER_MODESET))
436 vga_client_register(dev->pdev, NULL, NULL, NULL);
444 EXPORT_SYMBOL(drm_irq_install);
447 * drm_irq_uninstall - uninstall the IRQ handler
450 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
451 * This should only be called by drivers which used drm_irq_install() to set up
452 * their interrupt handler. Other drivers must only reset
453 * drm_device->irq_enabled to false.
455 * Note that for kernel modesetting drivers it is a bug if this function fails.
456 * The sanity checks are only to catch buggy user modesetting drivers which call
457 * the same function through an ioctl.
460 * Zero on success or a negative error code on failure.
462 int drm_irq_uninstall(struct drm_device *dev)
464 unsigned long irqflags;
468 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
471 irq_enabled = dev->irq_enabled;
472 dev->irq_enabled = false;
475 * Wake up any waiters so they don't hang. This is just to paper over
476 * isssues for UMS drivers which aren't in full control of their
477 * vblank/irq handling. KMS drivers must ensure that vblanks are all
478 * disabled when uninstalling the irq handler.
480 if (dev->num_crtcs) {
481 spin_lock_irqsave(&dev->vbl_lock, irqflags);
482 for (i = 0; i < dev->num_crtcs; i++) {
483 struct drm_vblank_crtc *vblank = &dev->vblank[i];
485 if (!vblank->enabled)
488 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
490 vblank_disable_and_save(dev, i);
491 wake_up(&vblank->queue);
493 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
499 DRM_DEBUG("irq=%d\n", dev->irq);
501 if (!drm_core_check_feature(dev, DRIVER_MODESET))
502 vga_client_register(dev->pdev, NULL, NULL, NULL);
504 if (dev->driver->irq_uninstall)
505 dev->driver->irq_uninstall(dev);
507 free_irq(dev->irq, dev);
511 EXPORT_SYMBOL(drm_irq_uninstall);
516 * \param inode device inode.
517 * \param file_priv DRM file private.
518 * \param cmd command.
519 * \param arg user argument, pointing to a drm_control structure.
520 * \return zero on success or a negative number on failure.
522 * Calls irq_install() or irq_uninstall() according to \p arg.
524 int drm_control(struct drm_device *dev, void *data,
525 struct drm_file *file_priv)
527 struct drm_control *ctl = data;
530 /* if we haven't irq we fallback for compatibility reasons -
531 * this used to be a separate function in drm_dma.h
534 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
536 if (drm_core_check_feature(dev, DRIVER_MODESET))
538 /* UMS was only ever support on pci devices. */
539 if (WARN_ON(!dev->pdev))
543 case DRM_INST_HANDLER:
544 irq = dev->pdev->irq;
546 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
549 mutex_lock(&dev->struct_mutex);
550 ret = drm_irq_install(dev, irq);
551 mutex_unlock(&dev->struct_mutex);
554 case DRM_UNINST_HANDLER:
555 mutex_lock(&dev->struct_mutex);
556 ret = drm_irq_uninstall(dev);
557 mutex_unlock(&dev->struct_mutex);
566 * drm_calc_timestamping_constants - calculate vblank timestamp constants
567 * @crtc: drm_crtc whose timestamp constants should be updated.
568 * @mode: display mode containing the scanout timings
570 * Calculate and store various constants which are later
571 * needed by vblank and swap-completion timestamping, e.g,
572 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
573 * derived from CRTC's true scanout timing, so they take
574 * things like panel scaling or other adjustments into account.
576 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
577 const struct drm_display_mode *mode)
579 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
580 int dotclock = mode->crtc_clock;
582 /* Valid dotclock? */
584 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
587 * Convert scanline length in pixels and video
588 * dot clock to line duration, frame duration
589 * and pixel duration in nanoseconds:
591 pixeldur_ns = 1000000 / dotclock;
592 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
593 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
596 * Fields of interlaced scanout modes are only half a frame duration.
598 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
601 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
604 crtc->pixeldur_ns = pixeldur_ns;
605 crtc->linedur_ns = linedur_ns;
606 crtc->framedur_ns = framedur_ns;
608 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
609 crtc->base.id, mode->crtc_htotal,
610 mode->crtc_vtotal, mode->crtc_vdisplay);
611 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
612 crtc->base.id, dotclock, framedur_ns,
613 linedur_ns, pixeldur_ns);
615 EXPORT_SYMBOL(drm_calc_timestamping_constants);
618 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
620 * @crtc: Which CRTC's vblank timestamp to retrieve
621 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
622 * On return contains true maximum error of timestamp
623 * @vblank_time: Pointer to struct timeval which should receive the timestamp
624 * @flags: Flags to pass to driver:
626 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
627 * @refcrtc: CRTC which defines scanout timing
628 * @mode: mode which defines the scanout timings
630 * Implements calculation of exact vblank timestamps from given drm_display_mode
631 * timings and current video scanout position of a CRTC. This can be called from
632 * within get_vblank_timestamp() implementation of a kms driver to implement the
633 * actual timestamping.
635 * Should return timestamps conforming to the OML_sync_control OpenML
636 * extension specification. The timestamp corresponds to the end of
637 * the vblank interval, aka start of scanout of topmost-leftmost display
638 * pixel in the following video frame.
640 * Requires support for optional dev->driver->get_scanout_position()
641 * in kms driver, plus a bit of setup code to provide a drm_display_mode
642 * that corresponds to the true scanout timing.
644 * The current implementation only handles standard video modes. It
645 * returns as no operation if a doublescan or interlaced video mode is
646 * active. Higher level code is expected to handle this.
649 * Negative value on error, failure or if not supported in current
652 * -EINVAL - Invalid CRTC.
653 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
654 * -ENOTSUPP - Function not supported in current display mode.
655 * -EIO - Failed, e.g., due to failed scanout position query.
657 * Returns or'ed positive status flags on success:
659 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
660 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
663 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
665 struct timeval *vblank_time,
667 const struct drm_crtc *refcrtc,
668 const struct drm_display_mode *mode)
670 struct timeval tv_etime;
671 ktime_t stime, etime;
674 int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
677 if (crtc < 0 || crtc >= dev->num_crtcs) {
678 DRM_ERROR("Invalid crtc %d\n", crtc);
682 /* Scanout position query not supported? Should not happen. */
683 if (!dev->driver->get_scanout_position) {
684 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
688 /* Durations of frames, lines, pixels in nanoseconds. */
689 framedur_ns = refcrtc->framedur_ns;
690 linedur_ns = refcrtc->linedur_ns;
691 pixeldur_ns = refcrtc->pixeldur_ns;
693 /* If mode timing undefined, just return as no-op:
694 * Happens during initial modesetting of a crtc.
696 if (framedur_ns == 0) {
697 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
701 /* Get current scanout position with system timestamp.
702 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
703 * if single query takes longer than max_error nanoseconds.
705 * This guarantees a tight bound on maximum error if
706 * code gets preempted or delayed for some reason.
708 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
710 * Get vertical and horizontal scanout position vpos, hpos,
711 * and bounding timestamps stime, etime, pre/post query.
713 vbl_status = dev->driver->get_scanout_position(dev, crtc, flags, &vpos,
714 &hpos, &stime, &etime);
716 /* Return as no-op if scanout query unsupported or failed. */
717 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
718 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
723 /* Compute uncertainty in timestamp of scanout position query. */
724 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
726 /* Accept result with < max_error nsecs timing uncertainty. */
727 if (duration_ns <= *max_error)
731 /* Noisy system timing? */
732 if (i == DRM_TIMESTAMP_MAXRETRIES) {
733 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
734 crtc, duration_ns/1000, *max_error/1000, i);
737 /* Return upper bound of timestamp precision error. */
738 *max_error = duration_ns;
740 /* Check if in vblank area:
741 * vpos is >=0 in video scanout area, but negative
742 * within vblank area, counting down the number of lines until
745 invbl = vbl_status & DRM_SCANOUTPOS_IN_VBLANK;
747 /* Convert scanout position into elapsed time at raw_time query
748 * since start of scanout at first display scanline. delta_ns
749 * can be negative if start of scanout hasn't happened yet.
751 delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
753 if (!drm_timestamp_monotonic)
754 etime = ktime_mono_to_real(etime);
756 /* save this only for debugging purposes */
757 tv_etime = ktime_to_timeval(etime);
758 /* Subtract time delta from raw timestamp to get final
759 * vblank_time timestamp for end of vblank.
762 etime = ktime_add_ns(etime, -delta_ns);
764 etime = ktime_sub_ns(etime, delta_ns);
765 *vblank_time = ktime_to_timeval(etime);
767 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
768 crtc, (int)vbl_status, hpos, vpos,
769 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
770 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
771 duration_ns/1000, i);
773 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
775 vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
779 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
781 static struct timeval get_drm_timestamp(void)
785 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
786 return ktime_to_timeval(now);
790 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
793 * @crtc: which CRTC's vblank timestamp to retrieve
794 * @tvblank: Pointer to target struct timeval which should receive the timestamp
795 * @flags: Flags to pass to driver:
797 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
799 * Fetches the system timestamp corresponding to the time of the most recent
800 * vblank interval on specified CRTC. May call into kms-driver to
801 * compute the timestamp with a high-precision GPU specific method.
803 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
804 * call, i.e., it isn't very precisely locked to the true vblank.
807 * True if timestamp is considered to be very precise, false otherwise.
810 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc,
811 struct timeval *tvblank, unsigned flags)
815 /* Define requested maximum error on timestamps (nanoseconds). */
816 int max_error = (int) drm_timestamp_precision * 1000;
818 /* Query driver if possible and precision timestamping enabled. */
819 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
820 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error,
826 /* GPU high precision timestamp query unsupported or failed.
827 * Return current monotonic/gettimeofday timestamp as best estimate.
829 *tvblank = get_drm_timestamp();
835 * drm_vblank_count - retrieve "cooked" vblank counter value
837 * @crtc: which counter to retrieve
839 * Fetches the "cooked" vblank count value that represents the number of
840 * vblank events since the system was booted, including lost events due to
841 * modesetting activity.
843 * This is the legacy version of drm_crtc_vblank_count().
846 * The software vblank counter.
848 u32 drm_vblank_count(struct drm_device *dev, int crtc)
850 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
852 if (WARN_ON(crtc >= dev->num_crtcs))
854 return atomic_read(&vblank->count);
856 EXPORT_SYMBOL(drm_vblank_count);
859 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
860 * @crtc: which counter to retrieve
862 * Fetches the "cooked" vblank count value that represents the number of
863 * vblank events since the system was booted, including lost events due to
864 * modesetting activity.
866 * This is the native KMS version of drm_vblank_count().
869 * The software vblank counter.
871 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
873 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
875 EXPORT_SYMBOL(drm_crtc_vblank_count);
878 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
879 * and the system timestamp corresponding to that vblank counter value.
882 * @crtc: which counter to retrieve
883 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
885 * Fetches the "cooked" vblank count value that represents the number of
886 * vblank events since the system was booted, including lost events due to
887 * modesetting activity. Returns corresponding system timestamp of the time
888 * of the vblank interval that corresponds to the current vblank counter value.
890 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc,
891 struct timeval *vblanktime)
893 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
896 if (WARN_ON(crtc >= dev->num_crtcs))
899 /* Read timestamp from slot of _vblank_time ringbuffer
900 * that corresponds to current vblank count. Retry if
901 * count has incremented during readout. This works like
905 cur_vblank = atomic_read(&vblank->count);
906 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank);
908 } while (cur_vblank != atomic_read(&vblank->count));
912 EXPORT_SYMBOL(drm_vblank_count_and_time);
914 static void send_vblank_event(struct drm_device *dev,
915 struct drm_pending_vblank_event *e,
916 unsigned long seq, struct timeval *now)
918 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
919 e->event.sequence = seq;
920 e->event.tv_sec = now->tv_sec;
921 e->event.tv_usec = now->tv_usec;
923 list_add_tail(&e->base.link,
924 &e->base.file_priv->event_list);
925 wake_up_interruptible(&e->base.file_priv->event_wait);
926 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
931 * drm_send_vblank_event - helper to send vblank event after pageflip
933 * @crtc: CRTC in question
934 * @e: the event to send
936 * Updates sequence # and timestamp on event, and sends it to userspace.
937 * Caller must hold event lock.
939 * This is the legacy version of drm_crtc_send_vblank_event().
941 void drm_send_vblank_event(struct drm_device *dev, int crtc,
942 struct drm_pending_vblank_event *e)
948 seq = drm_vblank_count_and_time(dev, crtc, &now);
952 now = get_drm_timestamp();
955 send_vblank_event(dev, e, seq, &now);
957 EXPORT_SYMBOL(drm_send_vblank_event);
960 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
961 * @crtc: the source CRTC of the vblank event
962 * @e: the event to send
964 * Updates sequence # and timestamp on event, and sends it to userspace.
965 * Caller must hold event lock.
967 * This is the native KMS version of drm_send_vblank_event().
969 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
970 struct drm_pending_vblank_event *e)
972 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
974 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
977 * drm_vblank_enable - enable the vblank interrupt on a CRTC
979 * @crtc: CRTC in question
981 static int drm_vblank_enable(struct drm_device *dev, int crtc)
983 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
986 assert_spin_locked(&dev->vbl_lock);
988 spin_lock(&dev->vblank_time_lock);
990 if (!vblank->enabled) {
992 * Enable vblank irqs under vblank_time_lock protection.
993 * All vblank count & timestamp updates are held off
994 * until we are done reinitializing master counter and
995 * timestamps. Filtercode in drm_handle_vblank() will
996 * prevent double-accounting of same vblank interval.
998 ret = dev->driver->enable_vblank(dev, crtc);
999 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc, ret);
1001 atomic_dec(&vblank->refcount);
1003 vblank->enabled = true;
1004 drm_update_vblank_count(dev, crtc);
1008 spin_unlock(&dev->vblank_time_lock);
1014 * drm_vblank_get - get a reference count on vblank events
1016 * @crtc: which CRTC to own
1018 * Acquire a reference count on vblank events to avoid having them disabled
1021 * This is the legacy version of drm_crtc_vblank_get().
1024 * Zero on success, nonzero on failure.
1026 int drm_vblank_get(struct drm_device *dev, int crtc)
1028 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1029 unsigned long irqflags;
1032 if (WARN_ON(crtc >= dev->num_crtcs))
1035 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1036 /* Going from 0->1 means we have to enable interrupts again */
1037 if (atomic_add_return(1, &vblank->refcount) == 1) {
1038 ret = drm_vblank_enable(dev, crtc);
1040 if (!vblank->enabled) {
1041 atomic_dec(&vblank->refcount);
1045 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1049 EXPORT_SYMBOL(drm_vblank_get);
1052 * drm_crtc_vblank_get - get a reference count on vblank events
1053 * @crtc: which CRTC to own
1055 * Acquire a reference count on vblank events to avoid having them disabled
1058 * This is the native kms version of drm_vblank_get().
1061 * Zero on success, nonzero on failure.
1063 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1065 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1067 EXPORT_SYMBOL(drm_crtc_vblank_get);
1070 * drm_vblank_put - give up ownership of vblank events
1072 * @crtc: which counter to give up
1074 * Release ownership of a given vblank counter, turning off interrupts
1075 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1077 * This is the legacy version of drm_crtc_vblank_put().
1079 void drm_vblank_put(struct drm_device *dev, int crtc)
1081 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1083 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1086 if (WARN_ON(crtc >= dev->num_crtcs))
1089 /* Last user schedules interrupt disable */
1090 if (atomic_dec_and_test(&vblank->refcount)) {
1091 if (drm_vblank_offdelay == 0)
1093 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1094 vblank_disable_fn((unsigned long)vblank);
1096 mod_timer(&vblank->disable_timer,
1097 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1100 EXPORT_SYMBOL(drm_vblank_put);
1103 * drm_crtc_vblank_put - give up ownership of vblank events
1104 * @crtc: which counter to give up
1106 * Release ownership of a given vblank counter, turning off interrupts
1107 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1109 * This is the native kms version of drm_vblank_put().
1111 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1113 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1115 EXPORT_SYMBOL(drm_crtc_vblank_put);
1118 * drm_wait_one_vblank - wait for one vblank
1122 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1123 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1124 * due to lack of driver support or because the crtc is off.
1126 void drm_wait_one_vblank(struct drm_device *dev, int crtc)
1131 ret = drm_vblank_get(dev, crtc);
1132 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", crtc, ret))
1135 last = drm_vblank_count(dev, crtc);
1137 ret = wait_event_timeout(dev->vblank[crtc].queue,
1138 last != drm_vblank_count(dev, crtc),
1139 msecs_to_jiffies(100));
1141 WARN(ret == 0, "vblank wait timed out on crtc %i\n", crtc);
1143 drm_vblank_put(dev, crtc);
1145 EXPORT_SYMBOL(drm_wait_one_vblank);
1148 * drm_crtc_wait_one_vblank - wait for one vblank
1151 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1152 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1153 * due to lack of driver support or because the crtc is off.
1155 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1157 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1159 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1162 * drm_vblank_off - disable vblank events on a CRTC
1164 * @crtc: CRTC in question
1166 * Drivers can use this function to shut down the vblank interrupt handling when
1167 * disabling a crtc. This function ensures that the latest vblank frame count is
1168 * stored so that drm_vblank_on() can restore it again.
1170 * Drivers must use this function when the hardware vblank counter can get
1171 * reset, e.g. when suspending.
1173 * This is the legacy version of drm_crtc_vblank_off().
1175 void drm_vblank_off(struct drm_device *dev, int crtc)
1177 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1178 struct drm_pending_vblank_event *e, *t;
1180 unsigned long irqflags;
1183 if (WARN_ON(crtc >= dev->num_crtcs))
1186 spin_lock_irqsave(&dev->event_lock, irqflags);
1188 spin_lock(&dev->vbl_lock);
1189 vblank_disable_and_save(dev, crtc);
1190 wake_up(&vblank->queue);
1193 * Prevent subsequent drm_vblank_get() from re-enabling
1194 * the vblank interrupt by bumping the refcount.
1196 if (!vblank->inmodeset) {
1197 atomic_inc(&vblank->refcount);
1198 vblank->inmodeset = 1;
1200 spin_unlock(&dev->vbl_lock);
1202 /* Send any queued vblank events, lest the natives grow disquiet */
1203 seq = drm_vblank_count_and_time(dev, crtc, &now);
1205 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1206 if (e->pipe != crtc)
1208 DRM_DEBUG("Sending premature vblank event on disable: \
1209 wanted %d, current %d\n",
1210 e->event.sequence, seq);
1211 list_del(&e->base.link);
1212 drm_vblank_put(dev, e->pipe);
1213 send_vblank_event(dev, e, seq, &now);
1215 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1217 EXPORT_SYMBOL(drm_vblank_off);
1220 * drm_crtc_vblank_off - disable vblank events on a CRTC
1221 * @crtc: CRTC in question
1223 * Drivers can use this function to shut down the vblank interrupt handling when
1224 * disabling a crtc. This function ensures that the latest vblank frame count is
1225 * stored so that drm_vblank_on can restore it again.
1227 * Drivers must use this function when the hardware vblank counter can get
1228 * reset, e.g. when suspending.
1230 * This is the native kms version of drm_vblank_off().
1232 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1234 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1236 EXPORT_SYMBOL(drm_crtc_vblank_off);
1239 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1240 * @crtc: CRTC in question
1242 * Drivers can use this function to reset the vblank state to off at load time.
1243 * Drivers should use this together with the drm_crtc_vblank_off() and
1244 * drm_crtc_vblank_on() functions. The difference compared to
1245 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1246 * and hence doesn't need to call any driver hooks.
1248 void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
1250 struct drm_device *dev = drm_crtc->dev;
1251 unsigned long irqflags;
1252 int crtc = drm_crtc_index(drm_crtc);
1253 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1255 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1257 * Prevent subsequent drm_vblank_get() from enabling the vblank
1258 * interrupt by bumping the refcount.
1260 if (!vblank->inmodeset) {
1261 atomic_inc(&vblank->refcount);
1262 vblank->inmodeset = 1;
1264 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1266 WARN_ON(!list_empty(&dev->vblank_event_list));
1268 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1271 * drm_vblank_on - enable vblank events on a CRTC
1273 * @crtc: CRTC in question
1275 * This functions restores the vblank interrupt state captured with
1276 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1277 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1278 * in driver load code to reflect the current hardware state of the crtc.
1280 * This is the legacy version of drm_crtc_vblank_on().
1282 void drm_vblank_on(struct drm_device *dev, int crtc)
1284 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1285 unsigned long irqflags;
1287 if (WARN_ON(crtc >= dev->num_crtcs))
1290 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1291 /* Drop our private "prevent drm_vblank_get" refcount */
1292 if (vblank->inmodeset) {
1293 atomic_dec(&vblank->refcount);
1294 vblank->inmodeset = 0;
1298 * sample the current counter to avoid random jumps
1299 * when drm_vblank_enable() applies the diff
1301 * -1 to make sure user will never see the same
1302 * vblank counter value before and after a modeset
1305 (dev->driver->get_vblank_counter(dev, crtc) - 1) &
1306 dev->max_vblank_count;
1308 * re-enable interrupts if there are users left, or the
1309 * user wishes vblank interrupts to be enabled all the time.
1311 if (atomic_read(&vblank->refcount) != 0 ||
1312 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1313 WARN_ON(drm_vblank_enable(dev, crtc));
1314 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1316 EXPORT_SYMBOL(drm_vblank_on);
1319 * drm_crtc_vblank_on - enable vblank events on a CRTC
1320 * @crtc: CRTC in question
1322 * This functions restores the vblank interrupt state captured with
1323 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1324 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1325 * in driver load code to reflect the current hardware state of the crtc.
1327 * This is the native kms version of drm_vblank_on().
1329 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1331 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1333 EXPORT_SYMBOL(drm_crtc_vblank_on);
1336 * drm_vblank_pre_modeset - account for vblanks across mode sets
1338 * @crtc: CRTC in question
1340 * Account for vblank events across mode setting events, which will likely
1341 * reset the hardware frame counter.
1343 * This is done by grabbing a temporary vblank reference to ensure that the
1344 * vblank interrupt keeps running across the modeset sequence. With this the
1345 * software-side vblank frame counting will ensure that there are no jumps or
1348 * Unfortunately this approach is racy and also doesn't work when the vblank
1349 * interrupt stops running, e.g. across system suspend resume. It is therefore
1350 * highly recommended that drivers use the newer drm_vblank_off() and
1351 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1352 * using "cooked" software vblank frame counters and not relying on any hardware
1355 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1358 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc)
1360 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1362 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1363 if (!dev->num_crtcs)
1366 if (WARN_ON(crtc >= dev->num_crtcs))
1370 * To avoid all the problems that might happen if interrupts
1371 * were enabled/disabled around or between these calls, we just
1372 * have the kernel take a reference on the CRTC (just once though
1373 * to avoid corrupting the count if multiple, mismatch calls occur),
1374 * so that interrupts remain enabled in the interim.
1376 if (!vblank->inmodeset) {
1377 vblank->inmodeset = 0x1;
1378 if (drm_vblank_get(dev, crtc) == 0)
1379 vblank->inmodeset |= 0x2;
1382 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1385 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1387 * @crtc: CRTC in question
1389 * This function again drops the temporary vblank reference acquired in
1390 * drm_vblank_pre_modeset.
1392 void drm_vblank_post_modeset(struct drm_device *dev, int crtc)
1394 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1395 unsigned long irqflags;
1397 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1398 if (!dev->num_crtcs)
1401 if (vblank->inmodeset) {
1402 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1403 dev->vblank_disable_allowed = true;
1404 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1406 if (vblank->inmodeset & 0x2)
1407 drm_vblank_put(dev, crtc);
1409 vblank->inmodeset = 0;
1412 EXPORT_SYMBOL(drm_vblank_post_modeset);
1415 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1416 * @DRM_IOCTL_ARGS: standard ioctl arguments
1418 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1419 * ioctls around modesetting so that any lost vblank events are accounted for.
1421 * Generally the counter will reset across mode sets. If interrupts are
1422 * enabled around this call, we don't have to do anything since the counter
1423 * will have already been incremented.
1425 int drm_modeset_ctl(struct drm_device *dev, void *data,
1426 struct drm_file *file_priv)
1428 struct drm_modeset_ctl *modeset = data;
1431 /* If drm_vblank_init() hasn't been called yet, just no-op */
1432 if (!dev->num_crtcs)
1435 /* KMS drivers handle this internally */
1436 if (drm_core_check_feature(dev, DRIVER_MODESET))
1439 crtc = modeset->crtc;
1440 if (crtc >= dev->num_crtcs)
1443 switch (modeset->cmd) {
1444 case _DRM_PRE_MODESET:
1445 drm_vblank_pre_modeset(dev, crtc);
1447 case _DRM_POST_MODESET:
1448 drm_vblank_post_modeset(dev, crtc);
1457 static int drm_queue_vblank_event(struct drm_device *dev, int pipe,
1458 union drm_wait_vblank *vblwait,
1459 struct drm_file *file_priv)
1461 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1462 struct drm_pending_vblank_event *e;
1464 unsigned long flags;
1468 e = kzalloc(sizeof(*e), GFP_KERNEL);
1475 e->base.pid = current->pid;
1476 e->event.base.type = DRM_EVENT_VBLANK;
1477 e->event.base.length = sizeof(e->event);
1478 e->event.user_data = vblwait->request.signal;
1479 e->base.event = &e->event.base;
1480 e->base.file_priv = file_priv;
1481 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1483 spin_lock_irqsave(&dev->event_lock, flags);
1486 * drm_vblank_off() might have been called after we called
1487 * drm_vblank_get(). drm_vblank_off() holds event_lock
1488 * around the vblank disable, so no need for further locking.
1489 * The reference from drm_vblank_get() protects against
1490 * vblank disable from another source.
1492 if (!vblank->enabled) {
1497 if (file_priv->event_space < sizeof(e->event)) {
1502 file_priv->event_space -= sizeof(e->event);
1503 seq = drm_vblank_count_and_time(dev, pipe, &now);
1505 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1506 (seq - vblwait->request.sequence) <= (1 << 23)) {
1507 vblwait->request.sequence = seq + 1;
1508 vblwait->reply.sequence = vblwait->request.sequence;
1511 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1512 vblwait->request.sequence, seq, pipe);
1514 trace_drm_vblank_event_queued(current->pid, pipe,
1515 vblwait->request.sequence);
1517 e->event.sequence = vblwait->request.sequence;
1518 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1519 drm_vblank_put(dev, pipe);
1520 send_vblank_event(dev, e, seq, &now);
1521 vblwait->reply.sequence = seq;
1523 /* drm_handle_vblank_events will call drm_vblank_put */
1524 list_add_tail(&e->base.link, &dev->vblank_event_list);
1525 vblwait->reply.sequence = vblwait->request.sequence;
1528 spin_unlock_irqrestore(&dev->event_lock, flags);
1533 spin_unlock_irqrestore(&dev->event_lock, flags);
1536 drm_vblank_put(dev, pipe);
1543 * \param inode device inode.
1544 * \param file_priv DRM file private.
1545 * \param cmd command.
1546 * \param data user argument, pointing to a drm_wait_vblank structure.
1547 * \return zero on success or a negative number on failure.
1549 * This function enables the vblank interrupt on the pipe requested, then
1550 * sleeps waiting for the requested sequence number to occur, and drops
1551 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1552 * after a timeout with no further vblank waits scheduled).
1554 int drm_wait_vblank(struct drm_device *dev, void *data,
1555 struct drm_file *file_priv)
1557 struct drm_vblank_crtc *vblank;
1558 union drm_wait_vblank *vblwait = data;
1560 unsigned int flags, seq, crtc, high_crtc;
1562 if (!dev->irq_enabled)
1565 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1568 if (vblwait->request.type &
1569 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1570 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1571 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1572 vblwait->request.type,
1573 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1574 _DRM_VBLANK_HIGH_CRTC_MASK));
1578 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1579 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1581 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1583 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1584 if (crtc >= dev->num_crtcs)
1587 vblank = &dev->vblank[crtc];
1589 ret = drm_vblank_get(dev, crtc);
1591 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1594 seq = drm_vblank_count(dev, crtc);
1596 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1597 case _DRM_VBLANK_RELATIVE:
1598 vblwait->request.sequence += seq;
1599 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1600 case _DRM_VBLANK_ABSOLUTE:
1607 if (flags & _DRM_VBLANK_EVENT) {
1608 /* must hold on to the vblank ref until the event fires
1609 * drm_vblank_put will be called asynchronously
1611 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv);
1614 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1615 (seq - vblwait->request.sequence) <= (1<<23)) {
1616 vblwait->request.sequence = seq + 1;
1619 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1620 vblwait->request.sequence, crtc);
1621 vblank->last_wait = vblwait->request.sequence;
1622 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1623 (((drm_vblank_count(dev, crtc) -
1624 vblwait->request.sequence) <= (1 << 23)) ||
1626 !dev->irq_enabled));
1628 if (ret != -EINTR) {
1631 vblwait->reply.sequence = drm_vblank_count_and_time(dev, crtc, &now);
1632 vblwait->reply.tval_sec = now.tv_sec;
1633 vblwait->reply.tval_usec = now.tv_usec;
1635 DRM_DEBUG("returning %d to client\n",
1636 vblwait->reply.sequence);
1638 DRM_DEBUG("vblank wait interrupted by signal\n");
1642 drm_vblank_put(dev, crtc);
1646 static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
1648 struct drm_pending_vblank_event *e, *t;
1652 assert_spin_locked(&dev->event_lock);
1654 seq = drm_vblank_count_and_time(dev, crtc, &now);
1656 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1657 if (e->pipe != crtc)
1659 if ((seq - e->event.sequence) > (1<<23))
1662 DRM_DEBUG("vblank event on %d, current %d\n",
1663 e->event.sequence, seq);
1665 list_del(&e->base.link);
1666 drm_vblank_put(dev, e->pipe);
1667 send_vblank_event(dev, e, seq, &now);
1670 trace_drm_vblank_event(crtc, seq);
1674 * drm_handle_vblank - handle a vblank event
1676 * @crtc: where this event occurred
1678 * Drivers should call this routine in their vblank interrupt handlers to
1679 * update the vblank counter and send any signals that may be pending.
1681 * This is the legacy version of drm_crtc_handle_vblank().
1683 bool drm_handle_vblank(struct drm_device *dev, int crtc)
1685 struct drm_vblank_crtc *vblank = &dev->vblank[crtc];
1688 struct timeval tvblank;
1689 unsigned long irqflags;
1691 if (WARN_ON_ONCE(!dev->num_crtcs))
1694 if (WARN_ON(crtc >= dev->num_crtcs))
1697 spin_lock_irqsave(&dev->event_lock, irqflags);
1699 /* Need timestamp lock to prevent concurrent execution with
1700 * vblank enable/disable, as this would cause inconsistent
1701 * or corrupted timestamps and vblank counts.
1703 spin_lock(&dev->vblank_time_lock);
1705 /* Vblank irq handling disabled. Nothing to do. */
1706 if (!vblank->enabled) {
1707 spin_unlock(&dev->vblank_time_lock);
1708 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1712 /* Fetch corresponding timestamp for this vblank interval from
1713 * driver and store it in proper slot of timestamp ringbuffer.
1716 /* Get current timestamp and count. */
1717 vblcount = atomic_read(&vblank->count);
1718 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1720 /* Compute time difference to timestamp of last vblank */
1721 diff_ns = timeval_to_ns(&tvblank) -
1722 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount));
1724 /* Update vblank timestamp and count if at least
1725 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1726 * difference between last stored timestamp and current
1727 * timestamp. A smaller difference means basically
1728 * identical timestamps. Happens if this vblank has
1729 * been already processed and this is a redundant call,
1730 * e.g., due to spurious vblank interrupts. We need to
1731 * ignore those for accounting.
1733 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) {
1734 /* Store new timestamp in ringbuffer. */
1735 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank;
1737 /* Increment cooked vblank count. This also atomically commits
1738 * the timestamp computed above.
1740 smp_mb__before_atomic();
1741 atomic_inc(&vblank->count);
1742 smp_mb__after_atomic();
1744 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1745 crtc, (int) diff_ns);
1748 spin_unlock(&dev->vblank_time_lock);
1750 wake_up(&vblank->queue);
1751 drm_handle_vblank_events(dev, crtc);
1753 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1757 EXPORT_SYMBOL(drm_handle_vblank);
1760 * drm_crtc_handle_vblank - handle a vblank event
1761 * @crtc: where this event occurred
1763 * Drivers should call this routine in their vblank interrupt handlers to
1764 * update the vblank counter and send any signals that may be pending.
1766 * This is the native KMS version of drm_handle_vblank().
1769 * True if the event was successfully handled, false on failure.
1771 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1773 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1775 EXPORT_SYMBOL(drm_crtc_handle_vblank);