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,
126 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
127 u32 cur_vblank, diff;
129 struct timeval t_vblank;
130 int count = DRM_TIMESTAMP_MAXRETRIES;
133 * Interrupts were disabled prior to this call, so deal with counter
135 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
136 * here if the register is small or we had vblank interrupts off for
139 * We repeat the hardware vblank counter & timestamp query until
140 * we get consistent results. This to prevent races between gpu
141 * updating its hardware counter while we are retrieving the
142 * corresponding vblank timestamp.
145 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
146 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
147 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
149 /* Deal with counter wrap */
150 diff = cur_vblank - vblank->last;
151 if (cur_vblank < vblank->last) {
152 diff += dev->max_vblank_count + 1;
154 DRM_DEBUG("last_vblank[%u]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
155 pipe, vblank->last, cur_vblank, diff);
158 DRM_DEBUG("updating vblank count on crtc %u, missed %d\n",
165 * Only reinitialize corresponding vblank timestamp if high-precision query
166 * available and didn't fail. Otherwise reinitialize delayed at next vblank
167 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
170 t_vblank = (struct timeval) {0, 0};
172 store_vblank(dev, pipe, diff, &t_vblank);
176 * Disable vblank irq's on crtc, make sure that last vblank count
177 * of hardware and corresponding consistent software vblank counter
178 * are preserved, even if there are any spurious vblank irq's after
181 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
183 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
184 unsigned long irqflags;
188 struct timeval tvblank;
189 int count = DRM_TIMESTAMP_MAXRETRIES;
191 /* Prevent vblank irq processing while disabling vblank irqs,
192 * so no updates of timestamps or count can happen after we've
193 * disabled. Needed to prevent races in case of delayed irq's.
195 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
198 * If the vblank interrupt was already disabled update the count
199 * and timestamp to maintain the appearance that the counter
200 * has been ticking all along until this time. This makes the
201 * count account for the entire time between drm_vblank_on() and
204 * But only do this if precise vblank timestamps are available.
205 * Otherwise we might read a totally bogus timestamp since drivers
206 * lacking precise timestamp support rely upon sampling the system clock
207 * at vblank interrupt time. Which obviously won't work out well if the
208 * vblank interrupt is disabled.
210 if (!vblank->enabled &&
211 drm_get_last_vbltimestamp(dev, pipe, &tvblank, 0)) {
212 drm_update_vblank_count(dev, pipe, 0);
213 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
218 * Only disable vblank interrupts if they're enabled. This avoids
219 * calling the ->disable_vblank() operation in atomic context with the
220 * hardware potentially runtime suspended.
222 if (vblank->enabled) {
223 dev->driver->disable_vblank(dev, pipe);
224 vblank->enabled = false;
227 /* No further vblank irq's will be processed after
228 * this point. Get current hardware vblank count and
229 * vblank timestamp, repeat until they are consistent.
231 * FIXME: There is still a race condition here and in
232 * drm_update_vblank_count() which can cause off-by-one
233 * reinitialization of software vblank counter. If gpu
234 * vblank counter doesn't increment exactly at the leading
235 * edge of a vblank interval, then we can lose 1 count if
236 * we happen to execute between start of vblank and the
237 * delayed gpu counter increment.
240 vblank->last = dev->driver->get_vblank_counter(dev, pipe);
241 vblrc = drm_get_last_vbltimestamp(dev, pipe, &tvblank, 0);
242 } while (vblank->last != dev->driver->get_vblank_counter(dev, pipe) && (--count) && vblrc);
247 /* Compute time difference to stored timestamp of last vblank
248 * as updated by last invocation of drm_handle_vblank() in vblank irq.
250 vblcount = vblank->count;
251 diff_ns = timeval_to_ns(&tvblank) -
252 timeval_to_ns(&vblanktimestamp(dev, pipe, vblcount));
254 /* If there is at least 1 msec difference between the last stored
255 * timestamp and tvblank, then we are currently executing our
256 * disable inside a new vblank interval, the tvblank timestamp
257 * corresponds to this new vblank interval and the irq handler
258 * for this vblank didn't run yet and won't run due to our disable.
259 * Therefore we need to do the job of drm_handle_vblank() and
260 * increment the vblank counter by one to account for this vblank.
262 * Skip this step if there isn't any high precision timestamp
263 * available. In that case we can't account for this and just
266 if (vblrc && (abs64(diff_ns) > 1000000))
267 store_vblank(dev, pipe, 1, &tvblank);
269 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
272 static void vblank_disable_fn(unsigned long arg)
274 struct drm_vblank_crtc *vblank = (void *)arg;
275 struct drm_device *dev = vblank->dev;
276 unsigned int pipe = vblank->pipe;
277 unsigned long irqflags;
279 if (!dev->vblank_disable_allowed)
282 spin_lock_irqsave(&dev->vbl_lock, irqflags);
283 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
284 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
285 vblank_disable_and_save(dev, pipe);
287 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
291 * drm_vblank_cleanup - cleanup vblank support
294 * This function cleans up any resources allocated in drm_vblank_init.
296 void drm_vblank_cleanup(struct drm_device *dev)
300 /* Bail if the driver didn't call drm_vblank_init() */
301 if (dev->num_crtcs == 0)
304 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
305 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
307 WARN_ON(vblank->enabled &&
308 drm_core_check_feature(dev, DRIVER_MODESET));
310 del_timer_sync(&vblank->disable_timer);
317 EXPORT_SYMBOL(drm_vblank_cleanup);
320 * drm_vblank_init - initialize vblank support
322 * @num_crtcs: number of CRTCs supported by @dev
324 * This function initializes vblank support for @num_crtcs display pipelines.
327 * Zero on success or a negative error code on failure.
329 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
334 spin_lock_init(&dev->vbl_lock);
335 spin_lock_init(&dev->vblank_time_lock);
337 dev->num_crtcs = num_crtcs;
339 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
343 for (i = 0; i < num_crtcs; i++) {
344 struct drm_vblank_crtc *vblank = &dev->vblank[i];
348 init_waitqueue_head(&vblank->queue);
349 setup_timer(&vblank->disable_timer, vblank_disable_fn,
350 (unsigned long)vblank);
353 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
355 /* Driver specific high-precision vblank timestamping supported? */
356 if (dev->driver->get_vblank_timestamp)
357 DRM_INFO("Driver supports precise vblank timestamp query.\n");
359 DRM_INFO("No driver support for vblank timestamp query.\n");
361 /* Must have precise timestamping for reliable vblank instant disable */
362 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
363 dev->vblank_disable_immediate = false;
364 DRM_INFO("Setting vblank_disable_immediate to false because "
365 "get_vblank_timestamp == NULL\n");
368 dev->vblank_disable_allowed = false;
376 EXPORT_SYMBOL(drm_vblank_init);
378 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
380 struct drm_device *dev = cookie;
382 if (dev->driver->vgaarb_irq) {
383 dev->driver->vgaarb_irq(dev, state);
387 if (!dev->irq_enabled)
391 if (dev->driver->irq_uninstall)
392 dev->driver->irq_uninstall(dev);
394 if (dev->driver->irq_preinstall)
395 dev->driver->irq_preinstall(dev);
396 if (dev->driver->irq_postinstall)
397 dev->driver->irq_postinstall(dev);
402 * drm_irq_install - install IRQ handler
404 * @irq: IRQ number to install the handler for
406 * Initializes the IRQ related data. Installs the handler, calling the driver
407 * irq_preinstall() and irq_postinstall() functions before and after the
410 * This is the simplified helper interface provided for drivers with no special
411 * needs. Drivers which need to install interrupt handlers for multiple
412 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
413 * that vblank interrupts are available.
416 * Zero on success or a negative error code on failure.
418 int drm_irq_install(struct drm_device *dev, int irq)
421 unsigned long sh_flags = 0;
423 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
429 /* Driver must have been initialized */
430 if (!dev->dev_private)
433 if (dev->irq_enabled)
435 dev->irq_enabled = true;
437 DRM_DEBUG("irq=%d\n", irq);
439 /* Before installing handler */
440 if (dev->driver->irq_preinstall)
441 dev->driver->irq_preinstall(dev);
443 /* Install handler */
444 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
445 sh_flags = IRQF_SHARED;
447 ret = request_irq(irq, dev->driver->irq_handler,
448 sh_flags, dev->driver->name, dev);
451 dev->irq_enabled = false;
455 if (!drm_core_check_feature(dev, DRIVER_MODESET))
456 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
458 /* After installing handler */
459 if (dev->driver->irq_postinstall)
460 ret = dev->driver->irq_postinstall(dev);
463 dev->irq_enabled = false;
464 if (!drm_core_check_feature(dev, DRIVER_MODESET))
465 vga_client_register(dev->pdev, NULL, NULL, NULL);
473 EXPORT_SYMBOL(drm_irq_install);
476 * drm_irq_uninstall - uninstall the IRQ handler
479 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
480 * This should only be called by drivers which used drm_irq_install() to set up
481 * their interrupt handler. Other drivers must only reset
482 * drm_device->irq_enabled to false.
484 * Note that for kernel modesetting drivers it is a bug if this function fails.
485 * The sanity checks are only to catch buggy user modesetting drivers which call
486 * the same function through an ioctl.
489 * Zero on success or a negative error code on failure.
491 int drm_irq_uninstall(struct drm_device *dev)
493 unsigned long irqflags;
497 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
500 irq_enabled = dev->irq_enabled;
501 dev->irq_enabled = false;
504 * Wake up any waiters so they don't hang. This is just to paper over
505 * isssues for UMS drivers which aren't in full control of their
506 * vblank/irq handling. KMS drivers must ensure that vblanks are all
507 * disabled when uninstalling the irq handler.
509 if (dev->num_crtcs) {
510 spin_lock_irqsave(&dev->vbl_lock, irqflags);
511 for (i = 0; i < dev->num_crtcs; i++) {
512 struct drm_vblank_crtc *vblank = &dev->vblank[i];
514 if (!vblank->enabled)
517 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
519 vblank_disable_and_save(dev, i);
520 wake_up(&vblank->queue);
522 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
528 DRM_DEBUG("irq=%d\n", dev->irq);
530 if (!drm_core_check_feature(dev, DRIVER_MODESET))
531 vga_client_register(dev->pdev, NULL, NULL, NULL);
533 if (dev->driver->irq_uninstall)
534 dev->driver->irq_uninstall(dev);
536 free_irq(dev->irq, dev);
540 EXPORT_SYMBOL(drm_irq_uninstall);
545 * \param inode device inode.
546 * \param file_priv DRM file private.
547 * \param cmd command.
548 * \param arg user argument, pointing to a drm_control structure.
549 * \return zero on success or a negative number on failure.
551 * Calls irq_install() or irq_uninstall() according to \p arg.
553 int drm_control(struct drm_device *dev, void *data,
554 struct drm_file *file_priv)
556 struct drm_control *ctl = data;
559 /* if we haven't irq we fallback for compatibility reasons -
560 * this used to be a separate function in drm_dma.h
563 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
565 if (drm_core_check_feature(dev, DRIVER_MODESET))
567 /* UMS was only ever support on pci devices. */
568 if (WARN_ON(!dev->pdev))
572 case DRM_INST_HANDLER:
573 irq = dev->pdev->irq;
575 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
578 mutex_lock(&dev->struct_mutex);
579 ret = drm_irq_install(dev, irq);
580 mutex_unlock(&dev->struct_mutex);
583 case DRM_UNINST_HANDLER:
584 mutex_lock(&dev->struct_mutex);
585 ret = drm_irq_uninstall(dev);
586 mutex_unlock(&dev->struct_mutex);
595 * drm_calc_timestamping_constants - calculate vblank timestamp constants
596 * @crtc: drm_crtc whose timestamp constants should be updated.
597 * @mode: display mode containing the scanout timings
599 * Calculate and store various constants which are later
600 * needed by vblank and swap-completion timestamping, e.g,
601 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
602 * derived from CRTC's true scanout timing, so they take
603 * things like panel scaling or other adjustments into account.
605 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
606 const struct drm_display_mode *mode)
608 struct drm_vblank_crtc *vblank = &crtc->dev->vblank[drm_crtc_index(crtc)];
609 int linedur_ns = 0, framedur_ns = 0;
610 int dotclock = mode->crtc_clock;
612 /* Valid dotclock? */
614 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
617 * Convert scanline length in pixels and video
618 * dot clock to line duration and frame duration
621 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
622 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
625 * Fields of interlaced scanout modes are only half a frame duration.
627 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
630 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
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\n",
640 crtc->base.id, dotclock, framedur_ns, linedur_ns);
642 EXPORT_SYMBOL(drm_calc_timestamping_constants);
645 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
647 * @pipe: index of CRTC whose vblank timestamp to retrieve
648 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
649 * On return contains true maximum error of timestamp
650 * @vblank_time: Pointer to struct timeval which should receive the timestamp
651 * @flags: Flags to pass to driver:
653 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
654 * @mode: mode which defines the scanout timings
656 * Implements calculation of exact vblank timestamps from given drm_display_mode
657 * timings and current video scanout position of a CRTC. This can be called from
658 * within get_vblank_timestamp() implementation of a kms driver to implement the
659 * actual timestamping.
661 * Should return timestamps conforming to the OML_sync_control OpenML
662 * extension specification. The timestamp corresponds to the end of
663 * the vblank interval, aka start of scanout of topmost-leftmost display
664 * pixel in the following video frame.
666 * Requires support for optional dev->driver->get_scanout_position()
667 * in kms driver, plus a bit of setup code to provide a drm_display_mode
668 * that corresponds to the true scanout timing.
670 * The current implementation only handles standard video modes. It
671 * returns as no operation if a doublescan or interlaced video mode is
672 * active. Higher level code is expected to handle this.
675 * Negative value on error, failure or if not supported in current
678 * -EINVAL - Invalid CRTC.
679 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
680 * -ENOTSUPP - Function not supported in current display mode.
681 * -EIO - Failed, e.g., due to failed scanout position query.
683 * Returns or'ed positive status flags on success:
685 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
686 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
689 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
692 struct timeval *vblank_time,
694 const struct drm_display_mode *mode)
696 struct timeval tv_etime;
697 ktime_t stime, etime;
698 unsigned int vbl_status;
699 int ret = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
701 int delta_ns, duration_ns;
703 if (pipe >= dev->num_crtcs) {
704 DRM_ERROR("Invalid crtc %u\n", pipe);
708 /* Scanout position query not supported? Should not happen. */
709 if (!dev->driver->get_scanout_position) {
710 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
714 /* If mode timing undefined, just return as no-op:
715 * Happens during initial modesetting of a crtc.
717 if (mode->crtc_clock == 0) {
718 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
722 /* Get current scanout position with system timestamp.
723 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
724 * if single query takes longer than max_error nanoseconds.
726 * This guarantees a tight bound on maximum error if
727 * code gets preempted or delayed for some reason.
729 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
731 * Get vertical and horizontal scanout position vpos, hpos,
732 * and bounding timestamps stime, etime, pre/post query.
734 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
739 /* Return as no-op if scanout query unsupported or failed. */
740 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
741 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
746 /* Compute uncertainty in timestamp of scanout position query. */
747 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
749 /* Accept result with < max_error nsecs timing uncertainty. */
750 if (duration_ns <= *max_error)
754 /* Noisy system timing? */
755 if (i == DRM_TIMESTAMP_MAXRETRIES) {
756 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
757 pipe, duration_ns/1000, *max_error/1000, i);
760 /* Return upper bound of timestamp precision error. */
761 *max_error = duration_ns;
763 /* Check if in vblank area:
764 * vpos is >=0 in video scanout area, but negative
765 * within vblank area, counting down the number of lines until
768 if (vbl_status & DRM_SCANOUTPOS_IN_VBLANK)
769 ret |= DRM_VBLANKTIME_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 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
793 pipe, 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);
800 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
802 static struct timeval get_drm_timestamp(void)
806 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
807 return ktime_to_timeval(now);
811 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
814 * @pipe: index of CRTC whose vblank timestamp to retrieve
815 * @tvblank: Pointer to target struct timeval which should receive the timestamp
816 * @flags: Flags to pass to driver:
818 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
820 * Fetches the system timestamp corresponding to the time of the most recent
821 * vblank interval on specified CRTC. May call into kms-driver to
822 * compute the timestamp with a high-precision GPU specific method.
824 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
825 * call, i.e., it isn't very precisely locked to the true vblank.
828 * True if timestamp is considered to be very precise, false otherwise.
831 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
832 struct timeval *tvblank, unsigned flags)
836 /* Define requested maximum error on timestamps (nanoseconds). */
837 int max_error = (int) drm_timestamp_precision * 1000;
839 /* Query driver if possible and precision timestamping enabled. */
840 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
841 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
847 /* GPU high precision timestamp query unsupported or failed.
848 * Return current monotonic/gettimeofday timestamp as best estimate.
850 *tvblank = get_drm_timestamp();
856 * drm_vblank_count - retrieve "cooked" vblank counter value
858 * @pipe: index of CRTC for which to retrieve the counter
860 * Fetches the "cooked" vblank count value that represents the number of
861 * vblank events since the system was booted, including lost events due to
862 * modesetting activity.
864 * This is the legacy version of drm_crtc_vblank_count().
867 * The software vblank counter.
869 u32 drm_vblank_count(struct drm_device *dev, int pipe)
871 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
873 if (WARN_ON(pipe >= dev->num_crtcs))
876 return vblank->count;
878 EXPORT_SYMBOL(drm_vblank_count);
881 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
882 * @crtc: which counter to retrieve
884 * Fetches the "cooked" vblank count value that represents the number of
885 * vblank events since the system was booted, including lost events due to
886 * modesetting activity.
888 * This is the native KMS version of drm_vblank_count().
891 * The software vblank counter.
893 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
895 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
897 EXPORT_SYMBOL(drm_crtc_vblank_count);
900 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
901 * system timestamp corresponding to that vblank counter value.
903 * @pipe: index of CRTC whose counter to retrieve
904 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
906 * Fetches the "cooked" vblank count value that represents the number of
907 * vblank events since the system was booted, including lost events due to
908 * modesetting activity. Returns corresponding system timestamp of the time
909 * of the vblank interval that corresponds to the current vblank counter value.
911 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
912 struct timeval *vblanktime)
914 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
915 int count = DRM_TIMESTAMP_MAXRETRIES;
918 if (WARN_ON(pipe >= dev->num_crtcs))
922 * Vblank timestamps are read lockless. To ensure consistency the vblank
923 * counter is rechecked and ordering is ensured using memory barriers.
924 * This works like a seqlock. The write-side barriers are in store_vblank.
927 cur_vblank = vblank->count;
929 *vblanktime = vblanktimestamp(dev, pipe, cur_vblank);
931 } while (cur_vblank != vblank->count && --count > 0);
935 EXPORT_SYMBOL(drm_vblank_count_and_time);
937 static void send_vblank_event(struct drm_device *dev,
938 struct drm_pending_vblank_event *e,
939 unsigned long seq, struct timeval *now)
941 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
942 e->event.sequence = seq;
943 e->event.tv_sec = now->tv_sec;
944 e->event.tv_usec = now->tv_usec;
946 list_add_tail(&e->base.link,
947 &e->base.file_priv->event_list);
948 wake_up_interruptible(&e->base.file_priv->event_wait);
949 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
954 * drm_send_vblank_event - helper to send vblank event after pageflip
957 * @e: the event to send
959 * Updates sequence # and timestamp on event, and sends it to userspace.
960 * Caller must hold event lock.
962 * This is the legacy version of drm_crtc_send_vblank_event().
964 void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
965 struct drm_pending_vblank_event *e)
970 if (dev->num_crtcs > 0) {
971 seq = drm_vblank_count_and_time(dev, pipe, &now);
975 now = get_drm_timestamp();
978 send_vblank_event(dev, e, seq, &now);
980 EXPORT_SYMBOL(drm_send_vblank_event);
983 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
984 * @crtc: the source CRTC of the vblank event
985 * @e: the event to send
987 * Updates sequence # and timestamp on event, and sends it to userspace.
988 * Caller must hold event lock.
990 * This is the native KMS version of drm_send_vblank_event().
992 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
993 struct drm_pending_vblank_event *e)
995 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
997 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1000 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1005 * Zero on success or a negative error code on failure.
1007 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1009 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1012 assert_spin_locked(&dev->vbl_lock);
1014 spin_lock(&dev->vblank_time_lock);
1016 if (!vblank->enabled) {
1018 * Enable vblank irqs under vblank_time_lock protection.
1019 * All vblank count & timestamp updates are held off
1020 * until we are done reinitializing master counter and
1021 * timestamps. Filtercode in drm_handle_vblank() will
1022 * prevent double-accounting of same vblank interval.
1024 ret = dev->driver->enable_vblank(dev, pipe);
1025 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1027 atomic_dec(&vblank->refcount);
1029 vblank->enabled = true;
1030 drm_update_vblank_count(dev, pipe, 0);
1034 spin_unlock(&dev->vblank_time_lock);
1040 * drm_vblank_get - get a reference count on vblank events
1042 * @pipe: index of CRTC to own
1044 * Acquire a reference count on vblank events to avoid having them disabled
1047 * This is the legacy version of drm_crtc_vblank_get().
1050 * Zero on success or a negative error code on failure.
1052 int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1054 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1055 unsigned long irqflags;
1058 if (!dev->num_crtcs)
1061 if (WARN_ON(pipe >= dev->num_crtcs))
1064 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1065 /* Going from 0->1 means we have to enable interrupts again */
1066 if (atomic_add_return(1, &vblank->refcount) == 1) {
1067 ret = drm_vblank_enable(dev, pipe);
1069 if (!vblank->enabled) {
1070 atomic_dec(&vblank->refcount);
1074 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1078 EXPORT_SYMBOL(drm_vblank_get);
1081 * drm_crtc_vblank_get - get a reference count on vblank events
1082 * @crtc: which CRTC to own
1084 * Acquire a reference count on vblank events to avoid having them disabled
1087 * This is the native kms version of drm_vblank_get().
1090 * Zero on success or a negative error code on failure.
1092 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1094 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1096 EXPORT_SYMBOL(drm_crtc_vblank_get);
1099 * drm_vblank_put - release ownership of vblank events
1101 * @pipe: index of CRTC to release
1103 * Release ownership of a given vblank counter, turning off interrupts
1104 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1106 * This is the legacy version of drm_crtc_vblank_put().
1108 void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1110 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1112 if (WARN_ON(pipe >= dev->num_crtcs))
1115 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1118 /* Last user schedules interrupt disable */
1119 if (atomic_dec_and_test(&vblank->refcount)) {
1120 if (drm_vblank_offdelay == 0)
1122 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1123 vblank_disable_fn((unsigned long)vblank);
1125 mod_timer(&vblank->disable_timer,
1126 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1129 EXPORT_SYMBOL(drm_vblank_put);
1132 * drm_crtc_vblank_put - give up ownership of vblank events
1133 * @crtc: which counter to give up
1135 * Release ownership of a given vblank counter, turning off interrupts
1136 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1138 * This is the native kms version of drm_vblank_put().
1140 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1142 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1144 EXPORT_SYMBOL(drm_crtc_vblank_put);
1147 * drm_wait_one_vblank - wait for one vblank
1151 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1152 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1153 * due to lack of driver support or because the crtc is off.
1155 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1157 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1161 if (WARN_ON(pipe >= dev->num_crtcs))
1164 ret = drm_vblank_get(dev, pipe);
1165 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1168 last = drm_vblank_count(dev, pipe);
1170 ret = wait_event_timeout(vblank->queue,
1171 last != drm_vblank_count(dev, pipe),
1172 msecs_to_jiffies(100));
1174 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1176 drm_vblank_put(dev, pipe);
1178 EXPORT_SYMBOL(drm_wait_one_vblank);
1181 * drm_crtc_wait_one_vblank - wait for one vblank
1184 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1185 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1186 * due to lack of driver support or because the crtc is off.
1188 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1190 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1192 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1195 * drm_vblank_off - disable vblank events on a CRTC
1199 * Drivers can use this function to shut down the vblank interrupt handling when
1200 * disabling a crtc. This function ensures that the latest vblank frame count is
1201 * stored so that drm_vblank_on() can restore it again.
1203 * Drivers must use this function when the hardware vblank counter can get
1204 * reset, e.g. when suspending.
1206 * This is the legacy version of drm_crtc_vblank_off().
1208 void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
1210 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1211 struct drm_pending_vblank_event *e, *t;
1213 unsigned long irqflags;
1216 if (WARN_ON(pipe >= dev->num_crtcs))
1219 spin_lock_irqsave(&dev->event_lock, irqflags);
1221 spin_lock(&dev->vbl_lock);
1222 vblank_disable_and_save(dev, pipe);
1223 wake_up(&vblank->queue);
1226 * Prevent subsequent drm_vblank_get() from re-enabling
1227 * the vblank interrupt by bumping the refcount.
1229 if (!vblank->inmodeset) {
1230 atomic_inc(&vblank->refcount);
1231 vblank->inmodeset = 1;
1233 spin_unlock(&dev->vbl_lock);
1235 /* Send any queued vblank events, lest the natives grow disquiet */
1236 seq = drm_vblank_count_and_time(dev, pipe, &now);
1238 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1239 if (e->pipe != pipe)
1241 DRM_DEBUG("Sending premature vblank event on disable: \
1242 wanted %d, current %d\n",
1243 e->event.sequence, seq);
1244 list_del(&e->base.link);
1245 drm_vblank_put(dev, pipe);
1246 send_vblank_event(dev, e, seq, &now);
1248 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1250 EXPORT_SYMBOL(drm_vblank_off);
1253 * drm_crtc_vblank_off - disable vblank events on a CRTC
1254 * @crtc: CRTC in question
1256 * Drivers can use this function to shut down the vblank interrupt handling when
1257 * disabling a crtc. This function ensures that the latest vblank frame count is
1258 * stored so that drm_vblank_on can restore it again.
1260 * Drivers must use this function when the hardware vblank counter can get
1261 * reset, e.g. when suspending.
1263 * This is the native kms version of drm_vblank_off().
1265 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1267 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1269 EXPORT_SYMBOL(drm_crtc_vblank_off);
1272 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1273 * @drm_crtc: CRTC in question
1275 * Drivers can use this function to reset the vblank state to off at load time.
1276 * Drivers should use this together with the drm_crtc_vblank_off() and
1277 * drm_crtc_vblank_on() functions. The difference compared to
1278 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1279 * and hence doesn't need to call any driver hooks.
1281 void drm_crtc_vblank_reset(struct drm_crtc *drm_crtc)
1283 struct drm_device *dev = drm_crtc->dev;
1284 unsigned long irqflags;
1285 unsigned int pipe = drm_crtc_index(drm_crtc);
1286 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1288 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1290 * Prevent subsequent drm_vblank_get() from enabling the vblank
1291 * interrupt by bumping the refcount.
1293 if (!vblank->inmodeset) {
1294 atomic_inc(&vblank->refcount);
1295 vblank->inmodeset = 1;
1297 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1299 WARN_ON(!list_empty(&dev->vblank_event_list));
1301 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1304 * drm_vblank_on - enable vblank events on a CRTC
1308 * This functions restores the vblank interrupt state captured with
1309 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1310 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1311 * in driver load code to reflect the current hardware state of the crtc.
1313 * This is the legacy version of drm_crtc_vblank_on().
1315 void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
1317 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1318 unsigned long irqflags;
1320 if (WARN_ON(pipe >= dev->num_crtcs))
1323 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1324 /* Drop our private "prevent drm_vblank_get" refcount */
1325 if (vblank->inmodeset) {
1326 atomic_dec(&vblank->refcount);
1327 vblank->inmodeset = 0;
1331 * sample the current counter to avoid random jumps
1332 * when drm_vblank_enable() applies the diff
1334 * -1 to make sure user will never see the same
1335 * vblank counter value before and after a modeset
1338 (dev->driver->get_vblank_counter(dev, pipe) - 1) &
1339 dev->max_vblank_count;
1341 * re-enable interrupts if there are users left, or the
1342 * user wishes vblank interrupts to be enabled all the time.
1344 if (atomic_read(&vblank->refcount) != 0 ||
1345 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1346 WARN_ON(drm_vblank_enable(dev, pipe));
1347 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1349 EXPORT_SYMBOL(drm_vblank_on);
1352 * drm_crtc_vblank_on - enable vblank events on a CRTC
1353 * @crtc: CRTC in question
1355 * This functions restores the vblank interrupt state captured with
1356 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1357 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1358 * in driver load code to reflect the current hardware state of the crtc.
1360 * This is the native kms version of drm_vblank_on().
1362 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1364 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1366 EXPORT_SYMBOL(drm_crtc_vblank_on);
1369 * drm_vblank_pre_modeset - account for vblanks across mode sets
1373 * Account for vblank events across mode setting events, which will likely
1374 * reset the hardware frame counter.
1376 * This is done by grabbing a temporary vblank reference to ensure that the
1377 * vblank interrupt keeps running across the modeset sequence. With this the
1378 * software-side vblank frame counting will ensure that there are no jumps or
1381 * Unfortunately this approach is racy and also doesn't work when the vblank
1382 * interrupt stops running, e.g. across system suspend resume. It is therefore
1383 * highly recommended that drivers use the newer drm_vblank_off() and
1384 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1385 * using "cooked" software vblank frame counters and not relying on any hardware
1388 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1391 void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
1393 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1395 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1396 if (!dev->num_crtcs)
1399 if (WARN_ON(pipe >= dev->num_crtcs))
1403 * To avoid all the problems that might happen if interrupts
1404 * were enabled/disabled around or between these calls, we just
1405 * have the kernel take a reference on the CRTC (just once though
1406 * to avoid corrupting the count if multiple, mismatch calls occur),
1407 * so that interrupts remain enabled in the interim.
1409 if (!vblank->inmodeset) {
1410 vblank->inmodeset = 0x1;
1411 if (drm_vblank_get(dev, pipe) == 0)
1412 vblank->inmodeset |= 0x2;
1415 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1418 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1422 * This function again drops the temporary vblank reference acquired in
1423 * drm_vblank_pre_modeset.
1425 void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
1427 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1428 unsigned long irqflags;
1430 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1431 if (!dev->num_crtcs)
1434 if (WARN_ON(pipe >= dev->num_crtcs))
1437 if (vblank->inmodeset) {
1438 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1439 dev->vblank_disable_allowed = true;
1440 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1442 if (vblank->inmodeset & 0x2)
1443 drm_vblank_put(dev, pipe);
1445 vblank->inmodeset = 0;
1448 EXPORT_SYMBOL(drm_vblank_post_modeset);
1451 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1452 * @DRM_IOCTL_ARGS: standard ioctl arguments
1454 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1455 * ioctls around modesetting so that any lost vblank events are accounted for.
1457 * Generally the counter will reset across mode sets. If interrupts are
1458 * enabled around this call, we don't have to do anything since the counter
1459 * will have already been incremented.
1461 int drm_modeset_ctl(struct drm_device *dev, void *data,
1462 struct drm_file *file_priv)
1464 struct drm_modeset_ctl *modeset = data;
1467 /* If drm_vblank_init() hasn't been called yet, just no-op */
1468 if (!dev->num_crtcs)
1471 /* KMS drivers handle this internally */
1472 if (drm_core_check_feature(dev, DRIVER_MODESET))
1475 pipe = modeset->crtc;
1476 if (pipe >= dev->num_crtcs)
1479 switch (modeset->cmd) {
1480 case _DRM_PRE_MODESET:
1481 drm_vblank_pre_modeset(dev, pipe);
1483 case _DRM_POST_MODESET:
1484 drm_vblank_post_modeset(dev, pipe);
1493 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1494 union drm_wait_vblank *vblwait,
1495 struct drm_file *file_priv)
1497 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1498 struct drm_pending_vblank_event *e;
1500 unsigned long flags;
1504 e = kzalloc(sizeof(*e), GFP_KERNEL);
1511 e->base.pid = current->pid;
1512 e->event.base.type = DRM_EVENT_VBLANK;
1513 e->event.base.length = sizeof(e->event);
1514 e->event.user_data = vblwait->request.signal;
1515 e->base.event = &e->event.base;
1516 e->base.file_priv = file_priv;
1517 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1519 spin_lock_irqsave(&dev->event_lock, flags);
1522 * drm_vblank_off() might have been called after we called
1523 * drm_vblank_get(). drm_vblank_off() holds event_lock
1524 * around the vblank disable, so no need for further locking.
1525 * The reference from drm_vblank_get() protects against
1526 * vblank disable from another source.
1528 if (!vblank->enabled) {
1533 if (file_priv->event_space < sizeof(e->event)) {
1538 file_priv->event_space -= sizeof(e->event);
1539 seq = drm_vblank_count_and_time(dev, pipe, &now);
1541 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1542 (seq - vblwait->request.sequence) <= (1 << 23)) {
1543 vblwait->request.sequence = seq + 1;
1544 vblwait->reply.sequence = vblwait->request.sequence;
1547 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1548 vblwait->request.sequence, seq, pipe);
1550 trace_drm_vblank_event_queued(current->pid, pipe,
1551 vblwait->request.sequence);
1553 e->event.sequence = vblwait->request.sequence;
1554 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1555 drm_vblank_put(dev, pipe);
1556 send_vblank_event(dev, e, seq, &now);
1557 vblwait->reply.sequence = seq;
1559 /* drm_handle_vblank_events will call drm_vblank_put */
1560 list_add_tail(&e->base.link, &dev->vblank_event_list);
1561 vblwait->reply.sequence = vblwait->request.sequence;
1564 spin_unlock_irqrestore(&dev->event_lock, flags);
1569 spin_unlock_irqrestore(&dev->event_lock, flags);
1572 drm_vblank_put(dev, pipe);
1579 * \param inode device inode.
1580 * \param file_priv DRM file private.
1581 * \param cmd command.
1582 * \param data user argument, pointing to a drm_wait_vblank structure.
1583 * \return zero on success or a negative number on failure.
1585 * This function enables the vblank interrupt on the pipe requested, then
1586 * sleeps waiting for the requested sequence number to occur, and drops
1587 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1588 * after a timeout with no further vblank waits scheduled).
1590 int drm_wait_vblank(struct drm_device *dev, void *data,
1591 struct drm_file *file_priv)
1593 struct drm_vblank_crtc *vblank;
1594 union drm_wait_vblank *vblwait = data;
1596 unsigned int flags, seq, pipe, high_pipe;
1598 if (!dev->irq_enabled)
1601 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1604 if (vblwait->request.type &
1605 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1606 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1607 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1608 vblwait->request.type,
1609 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1610 _DRM_VBLANK_HIGH_CRTC_MASK));
1614 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1615 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1617 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1619 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1620 if (pipe >= dev->num_crtcs)
1623 vblank = &dev->vblank[pipe];
1625 ret = drm_vblank_get(dev, pipe);
1627 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1630 seq = drm_vblank_count(dev, pipe);
1632 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1633 case _DRM_VBLANK_RELATIVE:
1634 vblwait->request.sequence += seq;
1635 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1636 case _DRM_VBLANK_ABSOLUTE:
1643 if (flags & _DRM_VBLANK_EVENT) {
1644 /* must hold on to the vblank ref until the event fires
1645 * drm_vblank_put will be called asynchronously
1647 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1650 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1651 (seq - vblwait->request.sequence) <= (1<<23)) {
1652 vblwait->request.sequence = seq + 1;
1655 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1656 vblwait->request.sequence, pipe);
1657 vblank->last_wait = vblwait->request.sequence;
1658 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1659 (((drm_vblank_count(dev, pipe) -
1660 vblwait->request.sequence) <= (1 << 23)) ||
1662 !dev->irq_enabled));
1664 if (ret != -EINTR) {
1667 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1668 vblwait->reply.tval_sec = now.tv_sec;
1669 vblwait->reply.tval_usec = now.tv_usec;
1671 DRM_DEBUG("returning %d to client\n",
1672 vblwait->reply.sequence);
1674 DRM_DEBUG("vblank wait interrupted by signal\n");
1678 drm_vblank_put(dev, pipe);
1682 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1684 struct drm_pending_vblank_event *e, *t;
1688 assert_spin_locked(&dev->event_lock);
1690 seq = drm_vblank_count_and_time(dev, pipe, &now);
1692 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1693 if (e->pipe != pipe)
1695 if ((seq - e->event.sequence) > (1<<23))
1698 DRM_DEBUG("vblank event on %d, current %d\n",
1699 e->event.sequence, seq);
1701 list_del(&e->base.link);
1702 drm_vblank_put(dev, pipe);
1703 send_vblank_event(dev, e, seq, &now);
1706 trace_drm_vblank_event(pipe, seq);
1710 * drm_handle_vblank - handle a vblank event
1712 * @pipe: index of CRTC where this event occurred
1714 * Drivers should call this routine in their vblank interrupt handlers to
1715 * update the vblank counter and send any signals that may be pending.
1717 * This is the legacy version of drm_crtc_handle_vblank().
1719 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1721 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1724 struct timeval tvblank;
1725 unsigned long irqflags;
1727 if (WARN_ON_ONCE(!dev->num_crtcs))
1730 if (WARN_ON(pipe >= dev->num_crtcs))
1733 spin_lock_irqsave(&dev->event_lock, irqflags);
1735 /* Need timestamp lock to prevent concurrent execution with
1736 * vblank enable/disable, as this would cause inconsistent
1737 * or corrupted timestamps and vblank counts.
1739 spin_lock(&dev->vblank_time_lock);
1741 /* Vblank irq handling disabled. Nothing to do. */
1742 if (!vblank->enabled) {
1743 spin_unlock(&dev->vblank_time_lock);
1744 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1748 /* Fetch corresponding timestamp for this vblank interval from
1749 * driver and store it in proper slot of timestamp ringbuffer.
1752 /* Get current timestamp and count. */
1753 vblcount = vblank->count;
1754 drm_get_last_vbltimestamp(dev, pipe, &tvblank, DRM_CALLED_FROM_VBLIRQ);
1756 /* Compute time difference to timestamp of last vblank */
1757 diff_ns = timeval_to_ns(&tvblank) -
1758 timeval_to_ns(&vblanktimestamp(dev, pipe, vblcount));
1760 /* Update vblank timestamp and count if at least
1761 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1762 * difference between last stored timestamp and current
1763 * timestamp. A smaller difference means basically
1764 * identical timestamps. Happens if this vblank has
1765 * been already processed and this is a redundant call,
1766 * e.g., due to spurious vblank interrupts. We need to
1767 * ignore those for accounting.
1769 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS)
1770 store_vblank(dev, pipe, 1, &tvblank);
1772 DRM_DEBUG("crtc %u: Redundant vblirq ignored. diff_ns = %d\n",
1773 pipe, (int) diff_ns);
1775 spin_unlock(&dev->vblank_time_lock);
1777 wake_up(&vblank->queue);
1778 drm_handle_vblank_events(dev, pipe);
1780 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1784 EXPORT_SYMBOL(drm_handle_vblank);
1787 * drm_crtc_handle_vblank - handle a vblank event
1788 * @crtc: where this event occurred
1790 * Drivers should call this routine in their vblank interrupt handlers to
1791 * update the vblank counter and send any signals that may be pending.
1793 * This is the native KMS version of drm_handle_vblank().
1796 * True if the event was successfully handled, false on failure.
1798 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1800 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1802 EXPORT_SYMBOL(drm_crtc_handle_vblank);