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, pipe, count) \
47 ((dev)->vblank[pipe].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, unsigned int pipe,
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);
77 static void store_vblank(struct drm_device *dev, unsigned int pipe,
79 struct timeval *t_vblank)
81 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
84 assert_spin_locked(&dev->vblank_time_lock);
87 /* All writers hold the spinlock, but readers are serialized by
88 * the latching of vblank->count below.
90 tslot = vblank->count + vblank_count_inc;
91 vblanktimestamp(dev, pipe, tslot) = *t_vblank;
95 * vblank timestamp updates are protected on the write side with
96 * vblank_time_lock, but on the read side done locklessly using a
97 * sequence-lock on the vblank counter. Ensure correct ordering using
98 * memory barrriers. We need the barrier both before and also after the
99 * counter update to synchronize with the next timestamp write.
100 * The read-side barriers for this are in drm_vblank_count_and_time.
103 vblank->count += vblank_count_inc;
108 * drm_update_vblank_count - update the master vblank counter
110 * @pipe: counter to update
112 * Call back into the driver to update the appropriate vblank counter
113 * (specified by @pipe). Deal with wraparound, if it occurred, and
114 * update the last read value so we can deal with wraparound on the next
117 * Only necessary when going from off->on, to account for frames we
118 * didn't get an interrupt for.
120 * Note: caller must hold dev->vbl_lock since this reads & writes
121 * device vblank fields.
123 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe)
125 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
126 u32 cur_vblank, diff;
128 struct timeval t_vblank;
131 * Interrupts were disabled prior to this call, so deal with counter
133 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
134 * here if the register is small or we had vblank interrupts off for
137 * We repeat the hardware vblank counter & timestamp query until
138 * we get consistent results. This to prevent races between gpu
139 * updating its hardware counter while we are retrieving the
140 * corresponding vblank timestamp.
143 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
144 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
145 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe));
147 /* Deal with counter wrap */
148 diff = cur_vblank - vblank->last;
149 if (cur_vblank < vblank->last) {
150 diff += dev->max_vblank_count + 1;
152 DRM_DEBUG("last_vblank[%u]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
153 pipe, vblank->last, cur_vblank, diff);
156 DRM_DEBUG("updating vblank count on crtc %u, missed %d\n",
163 * Only reinitialize corresponding vblank timestamp if high-precision query
164 * available and didn't fail. Otherwise reinitialize delayed at next vblank
165 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
168 t_vblank = (struct timeval) {0, 0};
170 store_vblank(dev, pipe, diff, &t_vblank);
174 * Disable vblank irq's on crtc, make sure that last vblank count
175 * of hardware and corresponding consistent software vblank counter
176 * are preserved, even if there are any spurious vblank irq's after
179 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
181 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
182 unsigned long irqflags;
186 struct timeval tvblank;
187 int count = DRM_TIMESTAMP_MAXRETRIES;
189 /* Prevent vblank irq processing while disabling vblank irqs,
190 * so no updates of timestamps or count can happen after we've
191 * disabled. Needed to prevent races in case of delayed irq's.
193 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
196 * If the vblank interrupt was already disabled update the count
197 * and timestamp to maintain the appearance that the counter
198 * has been ticking all along until this time. This makes the
199 * count account for the entire time between drm_vblank_on() and
202 * But only do this if precise vblank timestamps are available.
203 * Otherwise we might read a totally bogus timestamp since drivers
204 * lacking precise timestamp support rely upon sampling the system clock
205 * at vblank interrupt time. Which obviously won't work out well if the
206 * vblank interrupt is disabled.
208 if (!vblank->enabled &&
209 drm_get_last_vbltimestamp(dev, pipe, &tvblank, 0)) {
210 drm_update_vblank_count(dev, pipe);
211 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
216 * Only disable vblank interrupts if they're enabled. This avoids
217 * calling the ->disable_vblank() operation in atomic context with the
218 * hardware potentially runtime suspended.
220 if (vblank->enabled) {
221 dev->driver->disable_vblank(dev, pipe);
222 vblank->enabled = false;
225 /* No further vblank irq's will be processed after
226 * this point. Get current hardware vblank count and
227 * vblank timestamp, repeat until they are consistent.
229 * FIXME: There is still a race condition here and in
230 * drm_update_vblank_count() which can cause off-by-one
231 * reinitialization of software vblank counter. If gpu
232 * vblank counter doesn't increment exactly at the leading
233 * edge of a vblank interval, then we can lose 1 count if
234 * we happen to execute between start of vblank and the
235 * delayed gpu counter increment.
238 vblank->last = dev->driver->get_vblank_counter(dev, pipe);
239 vblrc = drm_get_last_vbltimestamp(dev, pipe, &tvblank, 0);
240 } while (vblank->last != dev->driver->get_vblank_counter(dev, pipe) && (--count) && vblrc);
245 /* Compute time difference to stored timestamp of last vblank
246 * as updated by last invocation of drm_handle_vblank() in vblank irq.
248 vblcount = vblank->count;
249 diff_ns = timeval_to_ns(&tvblank) -
250 timeval_to_ns(&vblanktimestamp(dev, pipe, vblcount));
252 /* If there is at least 1 msec difference between the last stored
253 * timestamp and tvblank, then we are currently executing our
254 * disable inside a new vblank interval, the tvblank timestamp
255 * corresponds to this new vblank interval and the irq handler
256 * for this vblank didn't run yet and won't run due to our disable.
257 * Therefore we need to do the job of drm_handle_vblank() and
258 * increment the vblank counter by one to account for this vblank.
260 * Skip this step if there isn't any high precision timestamp
261 * available. In that case we can't account for this and just
264 if (vblrc && (abs64(diff_ns) > 1000000))
265 store_vblank(dev, pipe, 1, &tvblank);
267 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
270 static void vblank_disable_fn(unsigned long arg)
272 struct drm_vblank_crtc *vblank = (void *)arg;
273 struct drm_device *dev = vblank->dev;
274 unsigned int pipe = vblank->pipe;
275 unsigned long irqflags;
277 if (!dev->vblank_disable_allowed)
280 spin_lock_irqsave(&dev->vbl_lock, irqflags);
281 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
282 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
283 vblank_disable_and_save(dev, pipe);
285 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
289 * drm_vblank_cleanup - cleanup vblank support
292 * This function cleans up any resources allocated in drm_vblank_init.
294 void drm_vblank_cleanup(struct drm_device *dev)
298 /* Bail if the driver didn't call drm_vblank_init() */
299 if (dev->num_crtcs == 0)
302 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
303 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
305 WARN_ON(vblank->enabled &&
306 drm_core_check_feature(dev, DRIVER_MODESET));
308 del_timer_sync(&vblank->disable_timer);
315 EXPORT_SYMBOL(drm_vblank_cleanup);
318 * drm_vblank_init - initialize vblank support
320 * @num_crtcs: number of CRTCs supported by @dev
322 * This function initializes vblank support for @num_crtcs display pipelines.
325 * Zero on success or a negative error code on failure.
327 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
332 spin_lock_init(&dev->vbl_lock);
333 spin_lock_init(&dev->vblank_time_lock);
335 dev->num_crtcs = num_crtcs;
337 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
341 for (i = 0; i < num_crtcs; i++) {
342 struct drm_vblank_crtc *vblank = &dev->vblank[i];
346 init_waitqueue_head(&vblank->queue);
347 setup_timer(&vblank->disable_timer, vblank_disable_fn,
348 (unsigned long)vblank);
351 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
353 /* Driver specific high-precision vblank timestamping supported? */
354 if (dev->driver->get_vblank_timestamp)
355 DRM_INFO("Driver supports precise vblank timestamp query.\n");
357 DRM_INFO("No driver support for vblank timestamp query.\n");
359 /* Must have precise timestamping for reliable vblank instant disable */
360 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
361 dev->vblank_disable_immediate = false;
362 DRM_INFO("Setting vblank_disable_immediate to false because "
363 "get_vblank_timestamp == NULL\n");
366 dev->vblank_disable_allowed = false;
374 EXPORT_SYMBOL(drm_vblank_init);
376 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
378 struct drm_device *dev = cookie;
380 if (dev->driver->vgaarb_irq) {
381 dev->driver->vgaarb_irq(dev, state);
385 if (!dev->irq_enabled)
389 if (dev->driver->irq_uninstall)
390 dev->driver->irq_uninstall(dev);
392 if (dev->driver->irq_preinstall)
393 dev->driver->irq_preinstall(dev);
394 if (dev->driver->irq_postinstall)
395 dev->driver->irq_postinstall(dev);
400 * drm_irq_install - install IRQ handler
402 * @irq: IRQ number to install the handler for
404 * Initializes the IRQ related data. Installs the handler, calling the driver
405 * irq_preinstall() and irq_postinstall() functions before and after the
408 * This is the simplified helper interface provided for drivers with no special
409 * needs. Drivers which need to install interrupt handlers for multiple
410 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
411 * that vblank interrupts are available.
414 * Zero on success or a negative error code on failure.
416 int drm_irq_install(struct drm_device *dev, int irq)
419 unsigned long sh_flags = 0;
421 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
427 /* Driver must have been initialized */
428 if (!dev->dev_private)
431 if (dev->irq_enabled)
433 dev->irq_enabled = true;
435 DRM_DEBUG("irq=%d\n", irq);
437 /* Before installing handler */
438 if (dev->driver->irq_preinstall)
439 dev->driver->irq_preinstall(dev);
441 /* Install handler */
442 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
443 sh_flags = IRQF_SHARED;
445 ret = request_irq(irq, dev->driver->irq_handler,
446 sh_flags, dev->driver->name, dev);
449 dev->irq_enabled = false;
453 if (!drm_core_check_feature(dev, DRIVER_MODESET))
454 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
456 /* After installing handler */
457 if (dev->driver->irq_postinstall)
458 ret = dev->driver->irq_postinstall(dev);
461 dev->irq_enabled = false;
462 if (!drm_core_check_feature(dev, DRIVER_MODESET))
463 vga_client_register(dev->pdev, NULL, NULL, NULL);
471 EXPORT_SYMBOL(drm_irq_install);
474 * drm_irq_uninstall - uninstall the IRQ handler
477 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
478 * This should only be called by drivers which used drm_irq_install() to set up
479 * their interrupt handler. Other drivers must only reset
480 * drm_device->irq_enabled to false.
482 * Note that for kernel modesetting drivers it is a bug if this function fails.
483 * The sanity checks are only to catch buggy user modesetting drivers which call
484 * the same function through an ioctl.
487 * Zero on success or a negative error code on failure.
489 int drm_irq_uninstall(struct drm_device *dev)
491 unsigned long irqflags;
495 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
498 irq_enabled = dev->irq_enabled;
499 dev->irq_enabled = false;
502 * Wake up any waiters so they don't hang. This is just to paper over
503 * isssues for UMS drivers which aren't in full control of their
504 * vblank/irq handling. KMS drivers must ensure that vblanks are all
505 * disabled when uninstalling the irq handler.
507 if (dev->num_crtcs) {
508 spin_lock_irqsave(&dev->vbl_lock, irqflags);
509 for (i = 0; i < dev->num_crtcs; i++) {
510 struct drm_vblank_crtc *vblank = &dev->vblank[i];
512 if (!vblank->enabled)
515 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
517 vblank_disable_and_save(dev, i);
518 wake_up(&vblank->queue);
520 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
526 DRM_DEBUG("irq=%d\n", dev->irq);
528 if (!drm_core_check_feature(dev, DRIVER_MODESET))
529 vga_client_register(dev->pdev, NULL, NULL, NULL);
531 if (dev->driver->irq_uninstall)
532 dev->driver->irq_uninstall(dev);
534 free_irq(dev->irq, dev);
538 EXPORT_SYMBOL(drm_irq_uninstall);
543 * \param inode device inode.
544 * \param file_priv DRM file private.
545 * \param cmd command.
546 * \param arg user argument, pointing to a drm_control structure.
547 * \return zero on success or a negative number on failure.
549 * Calls irq_install() or irq_uninstall() according to \p arg.
551 int drm_control(struct drm_device *dev, void *data,
552 struct drm_file *file_priv)
554 struct drm_control *ctl = data;
557 /* if we haven't irq we fallback for compatibility reasons -
558 * this used to be a separate function in drm_dma.h
561 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
563 if (drm_core_check_feature(dev, DRIVER_MODESET))
565 /* UMS was only ever support on pci devices. */
566 if (WARN_ON(!dev->pdev))
570 case DRM_INST_HANDLER:
571 irq = dev->pdev->irq;
573 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
576 mutex_lock(&dev->struct_mutex);
577 ret = drm_irq_install(dev, irq);
578 mutex_unlock(&dev->struct_mutex);
581 case DRM_UNINST_HANDLER:
582 mutex_lock(&dev->struct_mutex);
583 ret = drm_irq_uninstall(dev);
584 mutex_unlock(&dev->struct_mutex);
593 * drm_calc_timestamping_constants - calculate vblank timestamp constants
594 * @crtc: drm_crtc whose timestamp constants should be updated.
595 * @mode: display mode containing the scanout timings
597 * Calculate and store various constants which are later
598 * needed by vblank and swap-completion timestamping, e.g,
599 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
600 * derived from CRTC's true scanout timing, so they take
601 * things like panel scaling or other adjustments into account.
603 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
604 const struct drm_display_mode *mode)
606 struct drm_vblank_crtc *vblank = &crtc->dev->vblank[drm_crtc_index(crtc)];
607 int linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0;
608 int dotclock = mode->crtc_clock;
610 /* Valid dotclock? */
612 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
615 * Convert scanline length in pixels and video
616 * dot clock to line duration, frame duration
617 * and pixel duration in nanoseconds:
619 pixeldur_ns = 1000000 / dotclock;
620 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
621 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
624 * Fields of interlaced scanout modes are only half a frame duration.
626 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
629 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
632 vblank->pixeldur_ns = pixeldur_ns;
633 vblank->linedur_ns = linedur_ns;
634 vblank->framedur_ns = framedur_ns;
636 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
637 crtc->base.id, mode->crtc_htotal,
638 mode->crtc_vtotal, mode->crtc_vdisplay);
639 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
640 crtc->base.id, dotclock, framedur_ns,
641 linedur_ns, pixeldur_ns);
643 EXPORT_SYMBOL(drm_calc_timestamping_constants);
646 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
648 * @pipe: index of CRTC whose vblank timestamp to retrieve
649 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
650 * On return contains true maximum error of timestamp
651 * @vblank_time: Pointer to struct timeval which should receive the timestamp
652 * @flags: Flags to pass to driver:
654 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
655 * @mode: mode which defines the scanout timings
657 * Implements calculation of exact vblank timestamps from given drm_display_mode
658 * timings and current video scanout position of a CRTC. This can be called from
659 * within get_vblank_timestamp() implementation of a kms driver to implement the
660 * actual timestamping.
662 * Should return timestamps conforming to the OML_sync_control OpenML
663 * extension specification. The timestamp corresponds to the end of
664 * the vblank interval, aka start of scanout of topmost-leftmost display
665 * pixel in the following video frame.
667 * Requires support for optional dev->driver->get_scanout_position()
668 * in kms driver, plus a bit of setup code to provide a drm_display_mode
669 * that corresponds to the true scanout timing.
671 * The current implementation only handles standard video modes. It
672 * returns as no operation if a doublescan or interlaced video mode is
673 * active. Higher level code is expected to handle this.
676 * Negative value on error, failure or if not supported in current
679 * -EINVAL - Invalid CRTC.
680 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
681 * -ENOTSUPP - Function not supported in current display mode.
682 * -EIO - Failed, e.g., due to failed scanout position query.
684 * Returns or'ed positive status flags on success:
686 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
687 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
690 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
693 struct timeval *vblank_time,
695 const struct drm_display_mode *mode)
697 struct timeval tv_etime;
698 ktime_t stime, etime;
701 int delta_ns, duration_ns;
704 if (pipe >= dev->num_crtcs) {
705 DRM_ERROR("Invalid crtc %u\n", pipe);
709 /* Scanout position query not supported? Should not happen. */
710 if (!dev->driver->get_scanout_position) {
711 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
715 /* If mode timing undefined, just return as no-op:
716 * Happens during initial modesetting of a crtc.
718 if (mode->crtc_clock == 0) {
719 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
723 /* Get current scanout position with system timestamp.
724 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
725 * if single query takes longer than max_error nanoseconds.
727 * This guarantees a tight bound on maximum error if
728 * code gets preempted or delayed for some reason.
730 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
732 * Get vertical and horizontal scanout position vpos, hpos,
733 * and bounding timestamps stime, etime, pre/post query.
735 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
740 /* Return as no-op if scanout query unsupported or failed. */
741 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
742 DRM_DEBUG("crtc %u : scanoutpos query failed [%d].\n",
747 /* Compute uncertainty in timestamp of scanout position query. */
748 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
750 /* Accept result with < max_error nsecs timing uncertainty. */
751 if (duration_ns <= *max_error)
755 /* Noisy system timing? */
756 if (i == DRM_TIMESTAMP_MAXRETRIES) {
757 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
758 pipe, duration_ns/1000, *max_error/1000, i);
761 /* Return upper bound of timestamp precision error. */
762 *max_error = duration_ns;
764 /* Check if in vblank area:
765 * vpos is >=0 in video scanout area, but negative
766 * within vblank area, counting down the number of lines until
769 invbl = vbl_status & DRM_SCANOUTPOS_IN_VBLANK;
771 /* Convert scanout position into elapsed time at raw_time query
772 * since start of scanout at first display scanline. delta_ns
773 * can be negative if start of scanout hasn't happened yet.
775 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
778 if (!drm_timestamp_monotonic)
779 etime = ktime_mono_to_real(etime);
781 /* save this only for debugging purposes */
782 tv_etime = ktime_to_timeval(etime);
783 /* Subtract time delta from raw timestamp to get final
784 * vblank_time timestamp for end of vblank.
787 etime = ktime_add_ns(etime, -delta_ns);
789 etime = ktime_sub_ns(etime, delta_ns);
790 *vblank_time = ktime_to_timeval(etime);
792 DRM_DEBUG("crtc %u : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
793 pipe, (int)vbl_status, hpos, vpos,
794 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
795 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
796 duration_ns/1000, i);
798 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
800 vbl_status |= DRM_VBLANKTIME_IN_VBLANK;
804 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
806 static struct timeval get_drm_timestamp(void)
810 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
811 return ktime_to_timeval(now);
815 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
818 * @pipe: index of CRTC whose vblank timestamp to retrieve
819 * @tvblank: Pointer to target struct timeval which should receive the timestamp
820 * @flags: Flags to pass to driver:
822 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
824 * Fetches the system timestamp corresponding to the time of the most recent
825 * vblank interval on specified CRTC. May call into kms-driver to
826 * compute the timestamp with a high-precision GPU specific method.
828 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
829 * call, i.e., it isn't very precisely locked to the true vblank.
832 * True if timestamp is considered to be very precise, false otherwise.
835 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
836 struct timeval *tvblank, unsigned flags)
840 /* Define requested maximum error on timestamps (nanoseconds). */
841 int max_error = (int) drm_timestamp_precision * 1000;
843 /* Query driver if possible and precision timestamping enabled. */
844 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
845 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
851 /* GPU high precision timestamp query unsupported or failed.
852 * Return current monotonic/gettimeofday timestamp as best estimate.
854 *tvblank = get_drm_timestamp();
860 * drm_vblank_count - retrieve "cooked" vblank counter value
862 * @pipe: index of CRTC for which to retrieve the counter
864 * Fetches the "cooked" vblank count value that represents the number of
865 * vblank events since the system was booted, including lost events due to
866 * modesetting activity.
868 * This is the legacy version of drm_crtc_vblank_count().
871 * The software vblank counter.
873 u32 drm_vblank_count(struct drm_device *dev, int pipe)
875 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
877 if (WARN_ON(pipe >= dev->num_crtcs))
880 return vblank->count;
882 EXPORT_SYMBOL(drm_vblank_count);
885 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
886 * @crtc: which counter to retrieve
888 * Fetches the "cooked" vblank count value that represents the number of
889 * vblank events since the system was booted, including lost events due to
890 * modesetting activity.
892 * This is the native KMS version of drm_vblank_count().
895 * The software vblank counter.
897 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
899 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
901 EXPORT_SYMBOL(drm_crtc_vblank_count);
904 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
905 * system timestamp corresponding to that vblank counter value.
907 * @pipe: index of CRTC whose counter to retrieve
908 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
910 * Fetches the "cooked" vblank count value that represents the number of
911 * vblank events since the system was booted, including lost events due to
912 * modesetting activity. Returns corresponding system timestamp of the time
913 * of the vblank interval that corresponds to the current vblank counter value.
915 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
916 struct timeval *vblanktime)
918 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
921 if (WARN_ON(pipe >= dev->num_crtcs))
925 * Vblank timestamps are read lockless. To ensure consistency the vblank
926 * counter is rechecked and ordering is ensured using memory barriers.
927 * This works like a seqlock. The write-side barriers are in store_vblank.
930 cur_vblank = vblank->count;
932 *vblanktime = vblanktimestamp(dev, pipe, cur_vblank);
934 } while (cur_vblank != vblank->count);
938 EXPORT_SYMBOL(drm_vblank_count_and_time);
940 static void send_vblank_event(struct drm_device *dev,
941 struct drm_pending_vblank_event *e,
942 unsigned long seq, struct timeval *now)
944 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
945 e->event.sequence = seq;
946 e->event.tv_sec = now->tv_sec;
947 e->event.tv_usec = now->tv_usec;
949 list_add_tail(&e->base.link,
950 &e->base.file_priv->event_list);
951 wake_up_interruptible(&e->base.file_priv->event_wait);
952 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
957 * drm_send_vblank_event - helper to send vblank event after pageflip
960 * @e: the event to send
962 * Updates sequence # and timestamp on event, and sends it to userspace.
963 * Caller must hold event lock.
965 * This is the legacy version of drm_crtc_send_vblank_event().
967 void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
968 struct drm_pending_vblank_event *e)
973 if (dev->num_crtcs > 0) {
974 seq = drm_vblank_count_and_time(dev, pipe, &now);
978 now = get_drm_timestamp();
981 send_vblank_event(dev, e, seq, &now);
983 EXPORT_SYMBOL(drm_send_vblank_event);
986 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
987 * @crtc: the source CRTC of the vblank event
988 * @e: the event to send
990 * Updates sequence # and timestamp on event, and sends it to userspace.
991 * Caller must hold event lock.
993 * This is the native KMS version of drm_send_vblank_event().
995 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
996 struct drm_pending_vblank_event *e)
998 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1000 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1003 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1008 * Zero on success or a negative error code on failure.
1010 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1012 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1015 assert_spin_locked(&dev->vbl_lock);
1017 spin_lock(&dev->vblank_time_lock);
1019 if (!vblank->enabled) {
1021 * Enable vblank irqs under vblank_time_lock protection.
1022 * All vblank count & timestamp updates are held off
1023 * until we are done reinitializing master counter and
1024 * timestamps. Filtercode in drm_handle_vblank() will
1025 * prevent double-accounting of same vblank interval.
1027 ret = dev->driver->enable_vblank(dev, pipe);
1028 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1030 atomic_dec(&vblank->refcount);
1032 vblank->enabled = true;
1033 drm_update_vblank_count(dev, pipe);
1037 spin_unlock(&dev->vblank_time_lock);
1043 * drm_vblank_get - get a reference count on vblank events
1045 * @pipe: index of CRTC to own
1047 * Acquire a reference count on vblank events to avoid having them disabled
1050 * This is the legacy version of drm_crtc_vblank_get().
1053 * Zero on success or a negative error code on failure.
1055 int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1057 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1058 unsigned long irqflags;
1061 if (!dev->num_crtcs)
1064 if (WARN_ON(pipe >= dev->num_crtcs))
1067 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1068 /* Going from 0->1 means we have to enable interrupts again */
1069 if (atomic_add_return(1, &vblank->refcount) == 1) {
1070 ret = drm_vblank_enable(dev, pipe);
1072 if (!vblank->enabled) {
1073 atomic_dec(&vblank->refcount);
1077 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1081 EXPORT_SYMBOL(drm_vblank_get);
1084 * drm_crtc_vblank_get - get a reference count on vblank events
1085 * @crtc: which CRTC to own
1087 * Acquire a reference count on vblank events to avoid having them disabled
1090 * This is the native kms version of drm_vblank_get().
1093 * Zero on success or a negative error code on failure.
1095 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1097 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1099 EXPORT_SYMBOL(drm_crtc_vblank_get);
1102 * drm_vblank_put - release ownership of vblank events
1104 * @pipe: index of CRTC to release
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 legacy version of drm_crtc_vblank_put().
1111 void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1113 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1115 if (WARN_ON(pipe >= dev->num_crtcs))
1118 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1121 /* Last user schedules interrupt disable */
1122 if (atomic_dec_and_test(&vblank->refcount)) {
1123 if (drm_vblank_offdelay == 0)
1125 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1126 vblank_disable_fn((unsigned long)vblank);
1128 mod_timer(&vblank->disable_timer,
1129 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1132 EXPORT_SYMBOL(drm_vblank_put);
1135 * drm_crtc_vblank_put - give up ownership of vblank events
1136 * @crtc: which counter to give up
1138 * Release ownership of a given vblank counter, turning off interrupts
1139 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1141 * This is the native kms version of drm_vblank_put().
1143 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1145 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1147 EXPORT_SYMBOL(drm_crtc_vblank_put);
1150 * drm_wait_one_vblank - wait for one vblank
1154 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1155 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1156 * due to lack of driver support or because the crtc is off.
1158 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1160 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1164 if (WARN_ON(pipe >= dev->num_crtcs))
1167 ret = drm_vblank_get(dev, pipe);
1168 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1171 last = drm_vblank_count(dev, pipe);
1173 ret = wait_event_timeout(vblank->queue,
1174 last != drm_vblank_count(dev, pipe),
1175 msecs_to_jiffies(100));
1177 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1179 drm_vblank_put(dev, pipe);
1181 EXPORT_SYMBOL(drm_wait_one_vblank);
1184 * drm_crtc_wait_one_vblank - wait for one vblank
1187 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1188 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1189 * due to lack of driver support or because the crtc is off.
1191 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1193 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1195 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1198 * drm_vblank_off - disable vblank events on a CRTC
1202 * Drivers can use this function to shut down the vblank interrupt handling when
1203 * disabling a crtc. This function ensures that the latest vblank frame count is
1204 * stored so that drm_vblank_on() can restore it again.
1206 * Drivers must use this function when the hardware vblank counter can get
1207 * reset, e.g. when suspending.
1209 * This is the legacy version of drm_crtc_vblank_off().
1211 void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
1213 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1214 struct drm_pending_vblank_event *e, *t;
1216 unsigned long irqflags;
1219 if (WARN_ON(pipe >= dev->num_crtcs))
1222 spin_lock_irqsave(&dev->event_lock, irqflags);
1224 spin_lock(&dev->vbl_lock);
1225 vblank_disable_and_save(dev, pipe);
1226 wake_up(&vblank->queue);
1229 * Prevent subsequent drm_vblank_get() from re-enabling
1230 * the vblank interrupt by bumping the refcount.
1232 if (!vblank->inmodeset) {
1233 atomic_inc(&vblank->refcount);
1234 vblank->inmodeset = 1;
1236 spin_unlock(&dev->vbl_lock);
1238 /* Send any queued vblank events, lest the natives grow disquiet */
1239 seq = drm_vblank_count_and_time(dev, pipe, &now);
1241 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1242 if (e->pipe != pipe)
1244 DRM_DEBUG("Sending premature vblank event on disable: \
1245 wanted %d, current %d\n",
1246 e->event.sequence, seq);
1247 list_del(&e->base.link);
1248 drm_vblank_put(dev, pipe);
1249 send_vblank_event(dev, e, seq, &now);
1251 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1253 EXPORT_SYMBOL(drm_vblank_off);
1256 * drm_crtc_vblank_off - disable vblank events on a CRTC
1257 * @crtc: CRTC in question
1259 * Drivers can use this function to shut down the vblank interrupt handling when
1260 * disabling a crtc. This function ensures that the latest vblank frame count is
1261 * stored so that drm_vblank_on can restore it again.
1263 * Drivers must use this function when the hardware vblank counter can get
1264 * reset, e.g. when suspending.
1266 * This is the native kms version of drm_vblank_off().
1268 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1270 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1272 EXPORT_SYMBOL(drm_crtc_vblank_off);
1275 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1276 * @drm_crtc: CRTC in question
1278 * Drivers can use this function to reset the vblank state to off at load time.
1279 * Drivers should use this together with the drm_crtc_vblank_off() and
1280 * drm_crtc_vblank_on() functions. The difference compared to
1281 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1282 * and hence doesn't need to call any driver hooks.
1284 void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
1286 struct drm_device *dev = drm_crtc->dev;
1287 unsigned long irqflags;
1288 unsigned int pipe = drm_crtc_index(drm_crtc);
1289 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1291 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1293 * Prevent subsequent drm_vblank_get() from enabling the vblank
1294 * interrupt by bumping the refcount.
1296 if (!vblank->inmodeset) {
1297 atomic_inc(&vblank->refcount);
1298 vblank->inmodeset = 1;
1300 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1302 WARN_ON(!list_empty(&dev->vblank_event_list));
1304 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1307 * drm_vblank_on - enable vblank events on a CRTC
1311 * This functions restores the vblank interrupt state captured with
1312 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1313 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1314 * in driver load code to reflect the current hardware state of the crtc.
1316 * This is the legacy version of drm_crtc_vblank_on().
1318 void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
1320 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1321 unsigned long irqflags;
1323 if (WARN_ON(pipe >= dev->num_crtcs))
1326 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1327 /* Drop our private "prevent drm_vblank_get" refcount */
1328 if (vblank->inmodeset) {
1329 atomic_dec(&vblank->refcount);
1330 vblank->inmodeset = 0;
1334 * sample the current counter to avoid random jumps
1335 * when drm_vblank_enable() applies the diff
1337 * -1 to make sure user will never see the same
1338 * vblank counter value before and after a modeset
1341 (dev->driver->get_vblank_counter(dev, pipe) - 1) &
1342 dev->max_vblank_count;
1344 * re-enable interrupts if there are users left, or the
1345 * user wishes vblank interrupts to be enabled all the time.
1347 if (atomic_read(&vblank->refcount) != 0 ||
1348 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1349 WARN_ON(drm_vblank_enable(dev, pipe));
1350 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1352 EXPORT_SYMBOL(drm_vblank_on);
1355 * drm_crtc_vblank_on - enable vblank events on a CRTC
1356 * @crtc: CRTC in question
1358 * This functions restores the vblank interrupt state captured with
1359 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1360 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1361 * in driver load code to reflect the current hardware state of the crtc.
1363 * This is the native kms version of drm_vblank_on().
1365 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1367 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1369 EXPORT_SYMBOL(drm_crtc_vblank_on);
1372 * drm_vblank_pre_modeset - account for vblanks across mode sets
1376 * Account for vblank events across mode setting events, which will likely
1377 * reset the hardware frame counter.
1379 * This is done by grabbing a temporary vblank reference to ensure that the
1380 * vblank interrupt keeps running across the modeset sequence. With this the
1381 * software-side vblank frame counting will ensure that there are no jumps or
1384 * Unfortunately this approach is racy and also doesn't work when the vblank
1385 * interrupt stops running, e.g. across system suspend resume. It is therefore
1386 * highly recommended that drivers use the newer drm_vblank_off() and
1387 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1388 * using "cooked" software vblank frame counters and not relying on any hardware
1391 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1394 void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
1396 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1398 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1399 if (!dev->num_crtcs)
1402 if (WARN_ON(pipe >= dev->num_crtcs))
1406 * To avoid all the problems that might happen if interrupts
1407 * were enabled/disabled around or between these calls, we just
1408 * have the kernel take a reference on the CRTC (just once though
1409 * to avoid corrupting the count if multiple, mismatch calls occur),
1410 * so that interrupts remain enabled in the interim.
1412 if (!vblank->inmodeset) {
1413 vblank->inmodeset = 0x1;
1414 if (drm_vblank_get(dev, pipe) == 0)
1415 vblank->inmodeset |= 0x2;
1418 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1421 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1425 * This function again drops the temporary vblank reference acquired in
1426 * drm_vblank_pre_modeset.
1428 void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
1430 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1431 unsigned long irqflags;
1433 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1434 if (!dev->num_crtcs)
1437 if (WARN_ON(pipe >= dev->num_crtcs))
1440 if (vblank->inmodeset) {
1441 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1442 dev->vblank_disable_allowed = true;
1443 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1445 if (vblank->inmodeset & 0x2)
1446 drm_vblank_put(dev, pipe);
1448 vblank->inmodeset = 0;
1451 EXPORT_SYMBOL(drm_vblank_post_modeset);
1454 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1455 * @DRM_IOCTL_ARGS: standard ioctl arguments
1457 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1458 * ioctls around modesetting so that any lost vblank events are accounted for.
1460 * Generally the counter will reset across mode sets. If interrupts are
1461 * enabled around this call, we don't have to do anything since the counter
1462 * will have already been incremented.
1464 int drm_modeset_ctl(struct drm_device *dev, void *data,
1465 struct drm_file *file_priv)
1467 struct drm_modeset_ctl *modeset = data;
1470 /* If drm_vblank_init() hasn't been called yet, just no-op */
1471 if (!dev->num_crtcs)
1474 /* KMS drivers handle this internally */
1475 if (drm_core_check_feature(dev, DRIVER_MODESET))
1478 pipe = modeset->crtc;
1479 if (pipe >= dev->num_crtcs)
1482 switch (modeset->cmd) {
1483 case _DRM_PRE_MODESET:
1484 drm_vblank_pre_modeset(dev, pipe);
1486 case _DRM_POST_MODESET:
1487 drm_vblank_post_modeset(dev, pipe);
1496 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1497 union drm_wait_vblank *vblwait,
1498 struct drm_file *file_priv)
1500 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1501 struct drm_pending_vblank_event *e;
1503 unsigned long flags;
1507 e = kzalloc(sizeof(*e), GFP_KERNEL);
1514 e->base.pid = current->pid;
1515 e->event.base.type = DRM_EVENT_VBLANK;
1516 e->event.base.length = sizeof(e->event);
1517 e->event.user_data = vblwait->request.signal;
1518 e->base.event = &e->event.base;
1519 e->base.file_priv = file_priv;
1520 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1522 spin_lock_irqsave(&dev->event_lock, flags);
1525 * drm_vblank_off() might have been called after we called
1526 * drm_vblank_get(). drm_vblank_off() holds event_lock
1527 * around the vblank disable, so no need for further locking.
1528 * The reference from drm_vblank_get() protects against
1529 * vblank disable from another source.
1531 if (!vblank->enabled) {
1536 if (file_priv->event_space < sizeof(e->event)) {
1541 file_priv->event_space -= sizeof(e->event);
1542 seq = drm_vblank_count_and_time(dev, pipe, &now);
1544 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1545 (seq - vblwait->request.sequence) <= (1 << 23)) {
1546 vblwait->request.sequence = seq + 1;
1547 vblwait->reply.sequence = vblwait->request.sequence;
1550 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1551 vblwait->request.sequence, seq, pipe);
1553 trace_drm_vblank_event_queued(current->pid, pipe,
1554 vblwait->request.sequence);
1556 e->event.sequence = vblwait->request.sequence;
1557 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1558 drm_vblank_put(dev, pipe);
1559 send_vblank_event(dev, e, seq, &now);
1560 vblwait->reply.sequence = seq;
1562 /* drm_handle_vblank_events will call drm_vblank_put */
1563 list_add_tail(&e->base.link, &dev->vblank_event_list);
1564 vblwait->reply.sequence = vblwait->request.sequence;
1567 spin_unlock_irqrestore(&dev->event_lock, flags);
1572 spin_unlock_irqrestore(&dev->event_lock, flags);
1575 drm_vblank_put(dev, pipe);
1582 * \param inode device inode.
1583 * \param file_priv DRM file private.
1584 * \param cmd command.
1585 * \param data user argument, pointing to a drm_wait_vblank structure.
1586 * \return zero on success or a negative number on failure.
1588 * This function enables the vblank interrupt on the pipe requested, then
1589 * sleeps waiting for the requested sequence number to occur, and drops
1590 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1591 * after a timeout with no further vblank waits scheduled).
1593 int drm_wait_vblank(struct drm_device *dev, void *data,
1594 struct drm_file *file_priv)
1596 struct drm_vblank_crtc *vblank;
1597 union drm_wait_vblank *vblwait = data;
1599 unsigned int flags, seq, pipe, high_pipe;
1601 if (!dev->irq_enabled)
1604 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1607 if (vblwait->request.type &
1608 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1609 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1610 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1611 vblwait->request.type,
1612 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1613 _DRM_VBLANK_HIGH_CRTC_MASK));
1617 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1618 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1620 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1622 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1623 if (pipe >= dev->num_crtcs)
1626 vblank = &dev->vblank[pipe];
1628 ret = drm_vblank_get(dev, pipe);
1630 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1633 seq = drm_vblank_count(dev, pipe);
1635 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1636 case _DRM_VBLANK_RELATIVE:
1637 vblwait->request.sequence += seq;
1638 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1639 case _DRM_VBLANK_ABSOLUTE:
1646 if (flags & _DRM_VBLANK_EVENT) {
1647 /* must hold on to the vblank ref until the event fires
1648 * drm_vblank_put will be called asynchronously
1650 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1653 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1654 (seq - vblwait->request.sequence) <= (1<<23)) {
1655 vblwait->request.sequence = seq + 1;
1658 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1659 vblwait->request.sequence, pipe);
1660 vblank->last_wait = vblwait->request.sequence;
1661 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1662 (((drm_vblank_count(dev, pipe) -
1663 vblwait->request.sequence) <= (1 << 23)) ||
1665 !dev->irq_enabled));
1667 if (ret != -EINTR) {
1670 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1671 vblwait->reply.tval_sec = now.tv_sec;
1672 vblwait->reply.tval_usec = now.tv_usec;
1674 DRM_DEBUG("returning %d to client\n",
1675 vblwait->reply.sequence);
1677 DRM_DEBUG("vblank wait interrupted by signal\n");
1681 drm_vblank_put(dev, pipe);
1685 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1687 struct drm_pending_vblank_event *e, *t;
1691 assert_spin_locked(&dev->event_lock);
1693 seq = drm_vblank_count_and_time(dev, pipe, &now);
1695 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1696 if (e->pipe != pipe)
1698 if ((seq - e->event.sequence) > (1<<23))
1701 DRM_DEBUG("vblank event on %d, current %d\n",
1702 e->event.sequence, seq);
1704 list_del(&e->base.link);
1705 drm_vblank_put(dev, pipe);
1706 send_vblank_event(dev, e, seq, &now);
1709 trace_drm_vblank_event(pipe, seq);
1713 * drm_handle_vblank - handle a vblank event
1715 * @pipe: index of CRTC where this event occurred
1717 * Drivers should call this routine in their vblank interrupt handlers to
1718 * update the vblank counter and send any signals that may be pending.
1720 * This is the legacy version of drm_crtc_handle_vblank().
1722 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1724 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1727 struct timeval tvblank;
1728 unsigned long irqflags;
1730 if (WARN_ON_ONCE(!dev->num_crtcs))
1733 if (WARN_ON(pipe >= dev->num_crtcs))
1736 spin_lock_irqsave(&dev->event_lock, irqflags);
1738 /* Need timestamp lock to prevent concurrent execution with
1739 * vblank enable/disable, as this would cause inconsistent
1740 * or corrupted timestamps and vblank counts.
1742 spin_lock(&dev->vblank_time_lock);
1744 /* Vblank irq handling disabled. Nothing to do. */
1745 if (!vblank->enabled) {
1746 spin_unlock(&dev->vblank_time_lock);
1747 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1751 /* Fetch corresponding timestamp for this vblank interval from
1752 * driver and store it in proper slot of timestamp ringbuffer.
1755 /* Get current timestamp and count. */
1756 vblcount = vblank->count;
1757 drm_get_last_vbltimestamp(dev, pipe, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1759 /* Compute time difference to timestamp of last vblank */
1760 diff_ns = timeval_to_ns(&tvblank) -
1761 timeval_to_ns(&vblanktimestamp(dev, pipe, vblcount));
1763 /* Update vblank timestamp and count if at least
1764 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1765 * difference between last stored timestamp and current
1766 * timestamp. A smaller difference means basically
1767 * identical timestamps. Happens if this vblank has
1768 * been already processed and this is a redundant call,
1769 * e.g., due to spurious vblank interrupts. We need to
1770 * ignore those for accounting.
1772 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS)
1773 store_vblank(dev, pipe, 1, &tvblank);
1775 DRM_DEBUG("crtc %u: Redundant vblirq ignored. diff_ns = %d\n",
1776 pipe, (int) diff_ns);
1778 spin_unlock(&dev->vblank_time_lock);
1780 wake_up(&vblank->queue);
1781 drm_handle_vblank_events(dev, pipe);
1783 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1787 EXPORT_SYMBOL(drm_handle_vblank);
1790 * drm_crtc_handle_vblank - handle a vblank event
1791 * @crtc: where this event occurred
1793 * Drivers should call this routine in their vblank interrupt handlers to
1794 * update the vblank counter and send any signals that may be pending.
1796 * This is the native KMS version of drm_handle_vblank().
1799 * True if the event was successfully handled, false on failure.
1801 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1803 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1805 EXPORT_SYMBOL(drm_crtc_handle_vblank);