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, u32 last)
81 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
84 assert_spin_locked(&dev->vblank_time_lock);
88 /* All writers hold the spinlock, but readers are serialized by
89 * the latching of vblank->count below.
91 tslot = vblank->count + vblank_count_inc;
92 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_reset_vblank_timestamp - reset the last timestamp to the last vblank
110 * @pipe: index of CRTC for which to reset the timestamp
112 * Reset the stored timestamp for the current vblank count to correspond
113 * to the last vblank occurred.
115 * Only to be called from drm_vblank_on().
117 * Note: caller must hold dev->vbl_lock since this reads & writes
118 * device vblank fields.
120 static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
124 struct timeval t_vblank;
125 int count = DRM_TIMESTAMP_MAXRETRIES;
127 spin_lock(&dev->vblank_time_lock);
130 * sample the current counter to avoid random jumps
131 * when drm_vblank_enable() applies the diff
134 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
135 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
136 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
139 * Only reinitialize corresponding vblank timestamp if high-precision query
140 * available and didn't fail. Otherwise reinitialize delayed at next vblank
141 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
144 t_vblank = (struct timeval) {0, 0};
147 * +1 to make sure user will never see the same
148 * vblank counter value before and after a modeset
150 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
152 spin_unlock(&dev->vblank_time_lock);
156 * drm_update_vblank_count - update the master vblank counter
158 * @pipe: counter to update
160 * Call back into the driver to update the appropriate vblank counter
161 * (specified by @pipe). Deal with wraparound, if it occurred, and
162 * update the last read value so we can deal with wraparound on the next
165 * Only necessary when going from off->on, to account for frames we
166 * didn't get an interrupt for.
168 * Note: caller must hold dev->vbl_lock since this reads & writes
169 * device vblank fields.
171 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
174 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
175 u32 cur_vblank, diff;
177 struct timeval t_vblank;
178 int count = DRM_TIMESTAMP_MAXRETRIES;
179 int framedur_ns = vblank->framedur_ns;
182 * Interrupts were disabled prior to this call, so deal with counter
184 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
185 * here if the register is small or we had vblank interrupts off for
188 * We repeat the hardware vblank counter & timestamp query until
189 * we get consistent results. This to prevent races between gpu
190 * updating its hardware counter while we are retrieving the
191 * corresponding vblank timestamp.
194 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
195 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
196 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
198 if (dev->max_vblank_count != 0) {
199 /* trust the hw counter when it's around */
200 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
201 } else if (rc && framedur_ns) {
202 const struct timeval *t_old;
205 t_old = &vblanktimestamp(dev, pipe, vblank->count);
206 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
209 * Figure out how many vblanks we've missed based
210 * on the difference in the timestamps and the
211 * frame/field duration.
213 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
215 if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
216 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
217 " diff_ns = %lld, framedur_ns = %d)\n",
218 pipe, (long long) diff_ns, framedur_ns);
220 /* some kind of default for drivers w/o accurate vbl timestamping */
221 diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
224 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
225 " current=%u, diff=%u, hw=%u hw_last=%u\n",
226 pipe, vblank->count, diff, cur_vblank, vblank->last);
229 WARN_ON_ONCE(cur_vblank != vblank->last);
234 * Only reinitialize corresponding vblank timestamp if high-precision query
235 * available and didn't fail, or we were called from the vblank interrupt.
236 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
237 * for now, to mark the vblanktimestamp as invalid.
239 if (!rc && (flags & DRM_CALLED_FROM_VBLIRQ) == 0)
240 t_vblank = (struct timeval) {0, 0};
242 store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
246 * Disable vblank irq's on crtc, make sure that last vblank count
247 * of hardware and corresponding consistent software vblank counter
248 * are preserved, even if there are any spurious vblank irq's after
251 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
253 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
254 unsigned long irqflags;
256 /* Prevent vblank irq processing while disabling vblank irqs,
257 * so no updates of timestamps or count can happen after we've
258 * disabled. Needed to prevent races in case of delayed irq's.
260 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
263 * Only disable vblank interrupts if they're enabled. This avoids
264 * calling the ->disable_vblank() operation in atomic context with the
265 * hardware potentially runtime suspended.
267 if (vblank->enabled) {
268 dev->driver->disable_vblank(dev, pipe);
269 vblank->enabled = false;
273 * Always update the count and timestamp to maintain the
274 * appearance that the counter has been ticking all along until
275 * this time. This makes the count account for the entire time
276 * between drm_vblank_on() and drm_vblank_off().
278 drm_update_vblank_count(dev, pipe, 0);
280 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
283 static void vblank_disable_fn(unsigned long arg)
285 struct drm_vblank_crtc *vblank = (void *)arg;
286 struct drm_device *dev = vblank->dev;
287 unsigned int pipe = vblank->pipe;
288 unsigned long irqflags;
290 if (!dev->vblank_disable_allowed)
293 spin_lock_irqsave(&dev->vbl_lock, irqflags);
294 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
295 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
296 vblank_disable_and_save(dev, pipe);
298 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
302 * drm_vblank_cleanup - cleanup vblank support
305 * This function cleans up any resources allocated in drm_vblank_init.
307 void drm_vblank_cleanup(struct drm_device *dev)
311 /* Bail if the driver didn't call drm_vblank_init() */
312 if (dev->num_crtcs == 0)
315 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
316 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
318 WARN_ON(vblank->enabled &&
319 drm_core_check_feature(dev, DRIVER_MODESET));
321 del_timer_sync(&vblank->disable_timer);
328 EXPORT_SYMBOL(drm_vblank_cleanup);
331 * drm_vblank_init - initialize vblank support
333 * @num_crtcs: number of CRTCs supported by @dev
335 * This function initializes vblank support for @num_crtcs display pipelines.
338 * Zero on success or a negative error code on failure.
340 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
345 spin_lock_init(&dev->vbl_lock);
346 spin_lock_init(&dev->vblank_time_lock);
348 dev->num_crtcs = num_crtcs;
350 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
354 for (i = 0; i < num_crtcs; i++) {
355 struct drm_vblank_crtc *vblank = &dev->vblank[i];
359 init_waitqueue_head(&vblank->queue);
360 setup_timer(&vblank->disable_timer, vblank_disable_fn,
361 (unsigned long)vblank);
364 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
366 /* Driver specific high-precision vblank timestamping supported? */
367 if (dev->driver->get_vblank_timestamp)
368 DRM_INFO("Driver supports precise vblank timestamp query.\n");
370 DRM_INFO("No driver support for vblank timestamp query.\n");
372 /* Must have precise timestamping for reliable vblank instant disable */
373 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
374 dev->vblank_disable_immediate = false;
375 DRM_INFO("Setting vblank_disable_immediate to false because "
376 "get_vblank_timestamp == NULL\n");
379 dev->vblank_disable_allowed = false;
387 EXPORT_SYMBOL(drm_vblank_init);
389 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
391 struct drm_device *dev = cookie;
393 if (dev->driver->vgaarb_irq) {
394 dev->driver->vgaarb_irq(dev, state);
398 if (!dev->irq_enabled)
402 if (dev->driver->irq_uninstall)
403 dev->driver->irq_uninstall(dev);
405 if (dev->driver->irq_preinstall)
406 dev->driver->irq_preinstall(dev);
407 if (dev->driver->irq_postinstall)
408 dev->driver->irq_postinstall(dev);
413 * drm_irq_install - install IRQ handler
415 * @irq: IRQ number to install the handler for
417 * Initializes the IRQ related data. Installs the handler, calling the driver
418 * irq_preinstall() and irq_postinstall() functions before and after the
421 * This is the simplified helper interface provided for drivers with no special
422 * needs. Drivers which need to install interrupt handlers for multiple
423 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
424 * that vblank interrupts are available.
427 * Zero on success or a negative error code on failure.
429 int drm_irq_install(struct drm_device *dev, int irq)
432 unsigned long sh_flags = 0;
434 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
440 /* Driver must have been initialized */
441 if (!dev->dev_private)
444 if (dev->irq_enabled)
446 dev->irq_enabled = true;
448 DRM_DEBUG("irq=%d\n", irq);
450 /* Before installing handler */
451 if (dev->driver->irq_preinstall)
452 dev->driver->irq_preinstall(dev);
454 /* Install handler */
455 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
456 sh_flags = IRQF_SHARED;
458 ret = request_irq(irq, dev->driver->irq_handler,
459 sh_flags, dev->driver->name, dev);
462 dev->irq_enabled = false;
466 if (!drm_core_check_feature(dev, DRIVER_MODESET))
467 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
469 /* After installing handler */
470 if (dev->driver->irq_postinstall)
471 ret = dev->driver->irq_postinstall(dev);
474 dev->irq_enabled = false;
475 if (!drm_core_check_feature(dev, DRIVER_MODESET))
476 vga_client_register(dev->pdev, NULL, NULL, NULL);
484 EXPORT_SYMBOL(drm_irq_install);
487 * drm_irq_uninstall - uninstall the IRQ handler
490 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
491 * This should only be called by drivers which used drm_irq_install() to set up
492 * their interrupt handler. Other drivers must only reset
493 * drm_device->irq_enabled to false.
495 * Note that for kernel modesetting drivers it is a bug if this function fails.
496 * The sanity checks are only to catch buggy user modesetting drivers which call
497 * the same function through an ioctl.
500 * Zero on success or a negative error code on failure.
502 int drm_irq_uninstall(struct drm_device *dev)
504 unsigned long irqflags;
508 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
511 irq_enabled = dev->irq_enabled;
512 dev->irq_enabled = false;
515 * Wake up any waiters so they don't hang. This is just to paper over
516 * isssues for UMS drivers which aren't in full control of their
517 * vblank/irq handling. KMS drivers must ensure that vblanks are all
518 * disabled when uninstalling the irq handler.
520 if (dev->num_crtcs) {
521 spin_lock_irqsave(&dev->vbl_lock, irqflags);
522 for (i = 0; i < dev->num_crtcs; i++) {
523 struct drm_vblank_crtc *vblank = &dev->vblank[i];
525 if (!vblank->enabled)
528 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
530 vblank_disable_and_save(dev, i);
531 wake_up(&vblank->queue);
533 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
539 DRM_DEBUG("irq=%d\n", dev->irq);
541 if (!drm_core_check_feature(dev, DRIVER_MODESET))
542 vga_client_register(dev->pdev, NULL, NULL, NULL);
544 if (dev->driver->irq_uninstall)
545 dev->driver->irq_uninstall(dev);
547 free_irq(dev->irq, dev);
551 EXPORT_SYMBOL(drm_irq_uninstall);
556 * \param inode device inode.
557 * \param file_priv DRM file private.
558 * \param cmd command.
559 * \param arg user argument, pointing to a drm_control structure.
560 * \return zero on success or a negative number on failure.
562 * Calls irq_install() or irq_uninstall() according to \p arg.
564 int drm_control(struct drm_device *dev, void *data,
565 struct drm_file *file_priv)
567 struct drm_control *ctl = data;
570 /* if we haven't irq we fallback for compatibility reasons -
571 * this used to be a separate function in drm_dma.h
574 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
576 if (drm_core_check_feature(dev, DRIVER_MODESET))
578 /* UMS was only ever support on pci devices. */
579 if (WARN_ON(!dev->pdev))
583 case DRM_INST_HANDLER:
584 irq = dev->pdev->irq;
586 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
589 mutex_lock(&dev->struct_mutex);
590 ret = drm_irq_install(dev, irq);
591 mutex_unlock(&dev->struct_mutex);
594 case DRM_UNINST_HANDLER:
595 mutex_lock(&dev->struct_mutex);
596 ret = drm_irq_uninstall(dev);
597 mutex_unlock(&dev->struct_mutex);
606 * drm_calc_timestamping_constants - calculate vblank timestamp constants
607 * @crtc: drm_crtc whose timestamp constants should be updated.
608 * @mode: display mode containing the scanout timings
610 * Calculate and store various constants which are later
611 * needed by vblank and swap-completion timestamping, e.g,
612 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
613 * derived from CRTC's true scanout timing, so they take
614 * things like panel scaling or other adjustments into account.
616 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
617 const struct drm_display_mode *mode)
619 struct drm_vblank_crtc *vblank = &crtc->dev->vblank[drm_crtc_index(crtc)];
620 int linedur_ns = 0, framedur_ns = 0;
621 int dotclock = mode->crtc_clock;
623 /* Valid dotclock? */
625 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
628 * Convert scanline length in pixels and video
629 * dot clock to line duration and frame duration
632 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
633 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
636 * Fields of interlaced scanout modes are only half a frame duration.
638 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
641 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
644 vblank->linedur_ns = linedur_ns;
645 vblank->framedur_ns = framedur_ns;
647 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
648 crtc->base.id, mode->crtc_htotal,
649 mode->crtc_vtotal, mode->crtc_vdisplay);
650 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
651 crtc->base.id, dotclock, framedur_ns, linedur_ns);
653 EXPORT_SYMBOL(drm_calc_timestamping_constants);
656 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
658 * @pipe: index of CRTC whose vblank timestamp to retrieve
659 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
660 * On return contains true maximum error of timestamp
661 * @vblank_time: Pointer to struct timeval which should receive the timestamp
662 * @flags: Flags to pass to driver:
664 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
665 * @mode: mode which defines the scanout timings
667 * Implements calculation of exact vblank timestamps from given drm_display_mode
668 * timings and current video scanout position of a CRTC. This can be called from
669 * within get_vblank_timestamp() implementation of a kms driver to implement the
670 * actual timestamping.
672 * Should return timestamps conforming to the OML_sync_control OpenML
673 * extension specification. The timestamp corresponds to the end of
674 * the vblank interval, aka start of scanout of topmost-leftmost display
675 * pixel in the following video frame.
677 * Requires support for optional dev->driver->get_scanout_position()
678 * in kms driver, plus a bit of setup code to provide a drm_display_mode
679 * that corresponds to the true scanout timing.
681 * The current implementation only handles standard video modes. It
682 * returns as no operation if a doublescan or interlaced video mode is
683 * active. Higher level code is expected to handle this.
686 * Negative value on error, failure or if not supported in current
689 * -EINVAL - Invalid CRTC.
690 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
691 * -ENOTSUPP - Function not supported in current display mode.
692 * -EIO - Failed, e.g., due to failed scanout position query.
694 * Returns or'ed positive status flags on success:
696 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
697 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
700 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
703 struct timeval *vblank_time,
705 const struct drm_display_mode *mode)
707 struct timeval tv_etime;
708 ktime_t stime, etime;
709 unsigned int vbl_status;
710 int ret = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
712 int delta_ns, duration_ns;
714 if (pipe >= dev->num_crtcs) {
715 DRM_ERROR("Invalid crtc %u\n", pipe);
719 /* Scanout position query not supported? Should not happen. */
720 if (!dev->driver->get_scanout_position) {
721 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
725 /* If mode timing undefined, just return as no-op:
726 * Happens during initial modesetting of a crtc.
728 if (mode->crtc_clock == 0) {
729 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
733 /* Get current scanout position with system timestamp.
734 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
735 * if single query takes longer than max_error nanoseconds.
737 * This guarantees a tight bound on maximum error if
738 * code gets preempted or delayed for some reason.
740 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
742 * Get vertical and horizontal scanout position vpos, hpos,
743 * and bounding timestamps stime, etime, pre/post query.
745 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
750 /* Return as no-op if scanout query unsupported or failed. */
751 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
752 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
757 /* Compute uncertainty in timestamp of scanout position query. */
758 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
760 /* Accept result with < max_error nsecs timing uncertainty. */
761 if (duration_ns <= *max_error)
765 /* Noisy system timing? */
766 if (i == DRM_TIMESTAMP_MAXRETRIES) {
767 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
768 pipe, duration_ns/1000, *max_error/1000, i);
771 /* Return upper bound of timestamp precision error. */
772 *max_error = duration_ns;
774 /* Check if in vblank area:
775 * vpos is >=0 in video scanout area, but negative
776 * within vblank area, counting down the number of lines until
779 if (vbl_status & DRM_SCANOUTPOS_IN_VBLANK)
780 ret |= DRM_VBLANKTIME_IN_VBLANK;
782 /* Convert scanout position into elapsed time at raw_time query
783 * since start of scanout at first display scanline. delta_ns
784 * can be negative if start of scanout hasn't happened yet.
786 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
789 if (!drm_timestamp_monotonic)
790 etime = ktime_mono_to_real(etime);
792 /* save this only for debugging purposes */
793 tv_etime = ktime_to_timeval(etime);
794 /* Subtract time delta from raw timestamp to get final
795 * vblank_time timestamp for end of vblank.
798 etime = ktime_add_ns(etime, -delta_ns);
800 etime = ktime_sub_ns(etime, delta_ns);
801 *vblank_time = ktime_to_timeval(etime);
803 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
804 pipe, vbl_status, hpos, vpos,
805 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
806 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
807 duration_ns/1000, i);
811 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
813 static struct timeval get_drm_timestamp(void)
817 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
818 return ktime_to_timeval(now);
822 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
825 * @pipe: index of CRTC whose vblank timestamp to retrieve
826 * @tvblank: Pointer to target struct timeval which should receive the timestamp
827 * @flags: Flags to pass to driver:
829 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
831 * Fetches the system timestamp corresponding to the time of the most recent
832 * vblank interval on specified CRTC. May call into kms-driver to
833 * compute the timestamp with a high-precision GPU specific method.
835 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
836 * call, i.e., it isn't very precisely locked to the true vblank.
839 * True if timestamp is considered to be very precise, false otherwise.
842 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
843 struct timeval *tvblank, unsigned flags)
847 /* Define requested maximum error on timestamps (nanoseconds). */
848 int max_error = (int) drm_timestamp_precision * 1000;
850 /* Query driver if possible and precision timestamping enabled. */
851 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
852 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
858 /* GPU high precision timestamp query unsupported or failed.
859 * Return current monotonic/gettimeofday timestamp as best estimate.
861 *tvblank = get_drm_timestamp();
867 * drm_vblank_count - retrieve "cooked" vblank counter value
869 * @pipe: index of CRTC for which to retrieve the counter
871 * Fetches the "cooked" vblank count value that represents the number of
872 * vblank events since the system was booted, including lost events due to
873 * modesetting activity.
875 * This is the legacy version of drm_crtc_vblank_count().
878 * The software vblank counter.
880 u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
882 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
884 if (WARN_ON(pipe >= dev->num_crtcs))
887 return vblank->count;
889 EXPORT_SYMBOL(drm_vblank_count);
892 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
893 * @crtc: which counter to retrieve
895 * Fetches the "cooked" vblank count value that represents the number of
896 * vblank events since the system was booted, including lost events due to
897 * modesetting activity.
899 * This is the native KMS version of drm_vblank_count().
902 * The software vblank counter.
904 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
906 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
908 EXPORT_SYMBOL(drm_crtc_vblank_count);
911 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
912 * system timestamp corresponding to that vblank counter value.
914 * @pipe: index of CRTC whose counter to retrieve
915 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
917 * Fetches the "cooked" vblank count value that represents the number of
918 * vblank events since the system was booted, including lost events due to
919 * modesetting activity. Returns corresponding system timestamp of the time
920 * of the vblank interval that corresponds to the current vblank counter value.
922 * This is the legacy version of drm_crtc_vblank_count_and_time().
924 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
925 struct timeval *vblanktime)
927 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
928 int count = DRM_TIMESTAMP_MAXRETRIES;
931 if (WARN_ON(pipe >= dev->num_crtcs))
935 * Vblank timestamps are read lockless. To ensure consistency the vblank
936 * counter is rechecked and ordering is ensured using memory barriers.
937 * This works like a seqlock. The write-side barriers are in store_vblank.
940 cur_vblank = vblank->count;
942 *vblanktime = vblanktimestamp(dev, pipe, cur_vblank);
944 } while (cur_vblank != vblank->count && --count > 0);
948 EXPORT_SYMBOL(drm_vblank_count_and_time);
951 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
952 * and the system timestamp corresponding to that vblank counter value
953 * @crtc: which counter to retrieve
954 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
956 * Fetches the "cooked" vblank count value that represents the number of
957 * vblank events since the system was booted, including lost events due to
958 * modesetting activity. Returns corresponding system timestamp of the time
959 * of the vblank interval that corresponds to the current vblank counter value.
961 * This is the native KMS version of drm_vblank_count_and_time().
963 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
964 struct timeval *vblanktime)
966 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
969 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
971 static void send_vblank_event(struct drm_device *dev,
972 struct drm_pending_vblank_event *e,
973 unsigned long seq, struct timeval *now)
975 WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
976 e->event.sequence = seq;
977 e->event.tv_sec = now->tv_sec;
978 e->event.tv_usec = now->tv_usec;
980 list_add_tail(&e->base.link,
981 &e->base.file_priv->event_list);
982 wake_up_interruptible(&e->base.file_priv->event_wait);
983 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
988 * drm_send_vblank_event - helper to send vblank event after pageflip
991 * @e: the event to send
993 * Updates sequence # and timestamp on event, and sends it to userspace.
994 * Caller must hold event lock.
996 * This is the legacy version of drm_crtc_send_vblank_event().
998 void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
999 struct drm_pending_vblank_event *e)
1004 if (dev->num_crtcs > 0) {
1005 seq = drm_vblank_count_and_time(dev, pipe, &now);
1009 now = get_drm_timestamp();
1012 send_vblank_event(dev, e, seq, &now);
1014 EXPORT_SYMBOL(drm_send_vblank_event);
1017 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1018 * @crtc: the source CRTC of the vblank event
1019 * @e: the event to send
1021 * Updates sequence # and timestamp on event, and sends it to userspace.
1022 * Caller must hold event lock.
1024 * This is the native KMS version of drm_send_vblank_event().
1026 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1027 struct drm_pending_vblank_event *e)
1029 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1031 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1034 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1039 * Zero on success or a negative error code on failure.
1041 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1043 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1046 assert_spin_locked(&dev->vbl_lock);
1048 spin_lock(&dev->vblank_time_lock);
1050 if (!vblank->enabled) {
1052 * Enable vblank irqs under vblank_time_lock protection.
1053 * All vblank count & timestamp updates are held off
1054 * until we are done reinitializing master counter and
1055 * timestamps. Filtercode in drm_handle_vblank() will
1056 * prevent double-accounting of same vblank interval.
1058 ret = dev->driver->enable_vblank(dev, pipe);
1059 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1061 atomic_dec(&vblank->refcount);
1063 vblank->enabled = true;
1064 drm_update_vblank_count(dev, pipe, 0);
1068 spin_unlock(&dev->vblank_time_lock);
1074 * drm_vblank_get - get a reference count on vblank events
1076 * @pipe: index of CRTC to own
1078 * Acquire a reference count on vblank events to avoid having them disabled
1081 * This is the legacy version of drm_crtc_vblank_get().
1084 * Zero on success or a negative error code on failure.
1086 int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1088 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1089 unsigned long irqflags;
1092 if (!dev->num_crtcs)
1095 if (WARN_ON(pipe >= dev->num_crtcs))
1098 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1099 /* Going from 0->1 means we have to enable interrupts again */
1100 if (atomic_add_return(1, &vblank->refcount) == 1) {
1101 ret = drm_vblank_enable(dev, pipe);
1103 if (!vblank->enabled) {
1104 atomic_dec(&vblank->refcount);
1108 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1112 EXPORT_SYMBOL(drm_vblank_get);
1115 * drm_crtc_vblank_get - get a reference count on vblank events
1116 * @crtc: which CRTC to own
1118 * Acquire a reference count on vblank events to avoid having them disabled
1121 * This is the native kms version of drm_vblank_get().
1124 * Zero on success or a negative error code on failure.
1126 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1128 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1130 EXPORT_SYMBOL(drm_crtc_vblank_get);
1133 * drm_vblank_put - release ownership of vblank events
1135 * @pipe: index of CRTC to release
1137 * Release ownership of a given vblank counter, turning off interrupts
1138 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1140 * This is the legacy version of drm_crtc_vblank_put().
1142 void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1144 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1146 if (WARN_ON(pipe >= dev->num_crtcs))
1149 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1152 /* Last user schedules interrupt disable */
1153 if (atomic_dec_and_test(&vblank->refcount)) {
1154 if (drm_vblank_offdelay == 0)
1156 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1157 vblank_disable_fn((unsigned long)vblank);
1159 mod_timer(&vblank->disable_timer,
1160 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1163 EXPORT_SYMBOL(drm_vblank_put);
1166 * drm_crtc_vblank_put - give up ownership of vblank events
1167 * @crtc: which counter to give up
1169 * Release ownership of a given vblank counter, turning off interrupts
1170 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1172 * This is the native kms version of drm_vblank_put().
1174 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1176 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1178 EXPORT_SYMBOL(drm_crtc_vblank_put);
1181 * drm_wait_one_vblank - wait for one vblank
1185 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1186 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1187 * due to lack of driver support or because the crtc is off.
1189 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1191 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1195 if (WARN_ON(pipe >= dev->num_crtcs))
1198 ret = drm_vblank_get(dev, pipe);
1199 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1202 last = drm_vblank_count(dev, pipe);
1204 ret = wait_event_timeout(vblank->queue,
1205 last != drm_vblank_count(dev, pipe),
1206 msecs_to_jiffies(100));
1208 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1210 drm_vblank_put(dev, pipe);
1212 EXPORT_SYMBOL(drm_wait_one_vblank);
1215 * drm_crtc_wait_one_vblank - wait for one vblank
1218 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1219 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1220 * due to lack of driver support or because the crtc is off.
1222 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1224 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1226 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1229 * drm_vblank_off - disable vblank events on a CRTC
1233 * Drivers can use this function to shut down the vblank interrupt handling when
1234 * disabling a crtc. This function ensures that the latest vblank frame count is
1235 * stored so that drm_vblank_on() can restore it again.
1237 * Drivers must use this function when the hardware vblank counter can get
1238 * reset, e.g. when suspending.
1240 * This is the legacy version of drm_crtc_vblank_off().
1242 void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
1244 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1245 struct drm_pending_vblank_event *e, *t;
1247 unsigned long irqflags;
1250 if (WARN_ON(pipe >= dev->num_crtcs))
1253 spin_lock_irqsave(&dev->event_lock, irqflags);
1255 spin_lock(&dev->vbl_lock);
1256 vblank_disable_and_save(dev, pipe);
1257 wake_up(&vblank->queue);
1260 * Prevent subsequent drm_vblank_get() from re-enabling
1261 * the vblank interrupt by bumping the refcount.
1263 if (!vblank->inmodeset) {
1264 atomic_inc(&vblank->refcount);
1265 vblank->inmodeset = 1;
1267 spin_unlock(&dev->vbl_lock);
1269 /* Send any queued vblank events, lest the natives grow disquiet */
1270 seq = drm_vblank_count_and_time(dev, pipe, &now);
1272 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1273 if (e->pipe != pipe)
1275 DRM_DEBUG("Sending premature vblank event on disable: "
1276 "wanted %d, current %d\n",
1277 e->event.sequence, seq);
1278 list_del(&e->base.link);
1279 drm_vblank_put(dev, pipe);
1280 send_vblank_event(dev, e, seq, &now);
1282 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1284 EXPORT_SYMBOL(drm_vblank_off);
1287 * drm_crtc_vblank_off - disable vblank events on a CRTC
1288 * @crtc: CRTC in question
1290 * Drivers can use this function to shut down the vblank interrupt handling when
1291 * disabling a crtc. This function ensures that the latest vblank frame count is
1292 * stored so that drm_vblank_on can restore it again.
1294 * Drivers must use this function when the hardware vblank counter can get
1295 * reset, e.g. when suspending.
1297 * This is the native kms version of drm_vblank_off().
1299 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1301 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1303 EXPORT_SYMBOL(drm_crtc_vblank_off);
1306 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1307 * @crtc: CRTC in question
1309 * Drivers can use this function to reset the vblank state to off at load time.
1310 * Drivers should use this together with the drm_crtc_vblank_off() and
1311 * drm_crtc_vblank_on() functions. The difference compared to
1312 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1313 * and hence doesn't need to call any driver hooks.
1315 void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1317 struct drm_device *dev = crtc->dev;
1318 unsigned long irqflags;
1319 unsigned int pipe = drm_crtc_index(crtc);
1320 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1322 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1324 * Prevent subsequent drm_vblank_get() from enabling the vblank
1325 * interrupt by bumping the refcount.
1327 if (!vblank->inmodeset) {
1328 atomic_inc(&vblank->refcount);
1329 vblank->inmodeset = 1;
1331 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1333 WARN_ON(!list_empty(&dev->vblank_event_list));
1335 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1338 * drm_vblank_on - enable vblank events on a CRTC
1342 * This functions restores the vblank interrupt state captured with
1343 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1344 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1345 * in driver load code to reflect the current hardware state of the crtc.
1347 * This is the legacy version of drm_crtc_vblank_on().
1349 void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
1351 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1352 unsigned long irqflags;
1354 if (WARN_ON(pipe >= dev->num_crtcs))
1357 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1358 /* Drop our private "prevent drm_vblank_get" refcount */
1359 if (vblank->inmodeset) {
1360 atomic_dec(&vblank->refcount);
1361 vblank->inmodeset = 0;
1364 drm_reset_vblank_timestamp(dev, pipe);
1367 * re-enable interrupts if there are users left, or the
1368 * user wishes vblank interrupts to be enabled all the time.
1370 if (atomic_read(&vblank->refcount) != 0 ||
1371 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1372 WARN_ON(drm_vblank_enable(dev, pipe));
1373 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1375 EXPORT_SYMBOL(drm_vblank_on);
1378 * drm_crtc_vblank_on - enable vblank events on a CRTC
1379 * @crtc: CRTC in question
1381 * This functions restores the vblank interrupt state captured with
1382 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1383 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1384 * in driver load code to reflect the current hardware state of the crtc.
1386 * This is the native kms version of drm_vblank_on().
1388 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1390 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1392 EXPORT_SYMBOL(drm_crtc_vblank_on);
1395 * drm_vblank_pre_modeset - account for vblanks across mode sets
1399 * Account for vblank events across mode setting events, which will likely
1400 * reset the hardware frame counter.
1402 * This is done by grabbing a temporary vblank reference to ensure that the
1403 * vblank interrupt keeps running across the modeset sequence. With this the
1404 * software-side vblank frame counting will ensure that there are no jumps or
1407 * Unfortunately this approach is racy and also doesn't work when the vblank
1408 * interrupt stops running, e.g. across system suspend resume. It is therefore
1409 * highly recommended that drivers use the newer drm_vblank_off() and
1410 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1411 * using "cooked" software vblank frame counters and not relying on any hardware
1414 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1417 void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
1419 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1421 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1422 if (!dev->num_crtcs)
1425 if (WARN_ON(pipe >= dev->num_crtcs))
1429 * To avoid all the problems that might happen if interrupts
1430 * were enabled/disabled around or between these calls, we just
1431 * have the kernel take a reference on the CRTC (just once though
1432 * to avoid corrupting the count if multiple, mismatch calls occur),
1433 * so that interrupts remain enabled in the interim.
1435 if (!vblank->inmodeset) {
1436 vblank->inmodeset = 0x1;
1437 if (drm_vblank_get(dev, pipe) == 0)
1438 vblank->inmodeset |= 0x2;
1441 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1444 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1448 * This function again drops the temporary vblank reference acquired in
1449 * drm_vblank_pre_modeset.
1451 void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
1453 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1454 unsigned long irqflags;
1456 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1457 if (!dev->num_crtcs)
1460 if (WARN_ON(pipe >= dev->num_crtcs))
1463 if (vblank->inmodeset) {
1464 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1465 dev->vblank_disable_allowed = true;
1466 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1468 if (vblank->inmodeset & 0x2)
1469 drm_vblank_put(dev, pipe);
1471 vblank->inmodeset = 0;
1474 EXPORT_SYMBOL(drm_vblank_post_modeset);
1477 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1478 * @DRM_IOCTL_ARGS: standard ioctl arguments
1480 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1481 * ioctls around modesetting so that any lost vblank events are accounted for.
1483 * Generally the counter will reset across mode sets. If interrupts are
1484 * enabled around this call, we don't have to do anything since the counter
1485 * will have already been incremented.
1487 int drm_modeset_ctl(struct drm_device *dev, void *data,
1488 struct drm_file *file_priv)
1490 struct drm_modeset_ctl *modeset = data;
1493 /* If drm_vblank_init() hasn't been called yet, just no-op */
1494 if (!dev->num_crtcs)
1497 /* KMS drivers handle this internally */
1498 if (drm_core_check_feature(dev, DRIVER_MODESET))
1501 pipe = modeset->crtc;
1502 if (pipe >= dev->num_crtcs)
1505 switch (modeset->cmd) {
1506 case _DRM_PRE_MODESET:
1507 drm_vblank_pre_modeset(dev, pipe);
1509 case _DRM_POST_MODESET:
1510 drm_vblank_post_modeset(dev, pipe);
1519 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1520 union drm_wait_vblank *vblwait,
1521 struct drm_file *file_priv)
1523 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1524 struct drm_pending_vblank_event *e;
1526 unsigned long flags;
1530 e = kzalloc(sizeof(*e), GFP_KERNEL);
1537 e->base.pid = current->pid;
1538 e->event.base.type = DRM_EVENT_VBLANK;
1539 e->event.base.length = sizeof(e->event);
1540 e->event.user_data = vblwait->request.signal;
1541 e->base.event = &e->event.base;
1542 e->base.file_priv = file_priv;
1543 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1545 spin_lock_irqsave(&dev->event_lock, flags);
1548 * drm_vblank_off() might have been called after we called
1549 * drm_vblank_get(). drm_vblank_off() holds event_lock
1550 * around the vblank disable, so no need for further locking.
1551 * The reference from drm_vblank_get() protects against
1552 * vblank disable from another source.
1554 if (!vblank->enabled) {
1559 if (file_priv->event_space < sizeof(e->event)) {
1564 file_priv->event_space -= sizeof(e->event);
1565 seq = drm_vblank_count_and_time(dev, pipe, &now);
1567 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1568 (seq - vblwait->request.sequence) <= (1 << 23)) {
1569 vblwait->request.sequence = seq + 1;
1570 vblwait->reply.sequence = vblwait->request.sequence;
1573 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1574 vblwait->request.sequence, seq, pipe);
1576 trace_drm_vblank_event_queued(current->pid, pipe,
1577 vblwait->request.sequence);
1579 e->event.sequence = vblwait->request.sequence;
1580 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1581 drm_vblank_put(dev, pipe);
1582 send_vblank_event(dev, e, seq, &now);
1583 vblwait->reply.sequence = seq;
1585 /* drm_handle_vblank_events will call drm_vblank_put */
1586 list_add_tail(&e->base.link, &dev->vblank_event_list);
1587 vblwait->reply.sequence = vblwait->request.sequence;
1590 spin_unlock_irqrestore(&dev->event_lock, flags);
1595 spin_unlock_irqrestore(&dev->event_lock, flags);
1598 drm_vblank_put(dev, pipe);
1605 * \param inode device inode.
1606 * \param file_priv DRM file private.
1607 * \param cmd command.
1608 * \param data user argument, pointing to a drm_wait_vblank structure.
1609 * \return zero on success or a negative number on failure.
1611 * This function enables the vblank interrupt on the pipe requested, then
1612 * sleeps waiting for the requested sequence number to occur, and drops
1613 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1614 * after a timeout with no further vblank waits scheduled).
1616 int drm_wait_vblank(struct drm_device *dev, void *data,
1617 struct drm_file *file_priv)
1619 struct drm_vblank_crtc *vblank;
1620 union drm_wait_vblank *vblwait = data;
1622 unsigned int flags, seq, pipe, high_pipe;
1624 if (!dev->irq_enabled)
1627 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1630 if (vblwait->request.type &
1631 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1632 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1633 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1634 vblwait->request.type,
1635 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1636 _DRM_VBLANK_HIGH_CRTC_MASK));
1640 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1641 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1643 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1645 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1646 if (pipe >= dev->num_crtcs)
1649 vblank = &dev->vblank[pipe];
1651 ret = drm_vblank_get(dev, pipe);
1653 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1656 seq = drm_vblank_count(dev, pipe);
1658 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1659 case _DRM_VBLANK_RELATIVE:
1660 vblwait->request.sequence += seq;
1661 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1662 case _DRM_VBLANK_ABSOLUTE:
1669 if (flags & _DRM_VBLANK_EVENT) {
1670 /* must hold on to the vblank ref until the event fires
1671 * drm_vblank_put will be called asynchronously
1673 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1676 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1677 (seq - vblwait->request.sequence) <= (1<<23)) {
1678 vblwait->request.sequence = seq + 1;
1681 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1682 vblwait->request.sequence, pipe);
1683 vblank->last_wait = vblwait->request.sequence;
1684 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1685 (((drm_vblank_count(dev, pipe) -
1686 vblwait->request.sequence) <= (1 << 23)) ||
1688 !dev->irq_enabled));
1690 if (ret != -EINTR) {
1693 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1694 vblwait->reply.tval_sec = now.tv_sec;
1695 vblwait->reply.tval_usec = now.tv_usec;
1697 DRM_DEBUG("returning %d to client\n",
1698 vblwait->reply.sequence);
1700 DRM_DEBUG("vblank wait interrupted by signal\n");
1704 drm_vblank_put(dev, pipe);
1708 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1710 struct drm_pending_vblank_event *e, *t;
1714 assert_spin_locked(&dev->event_lock);
1716 seq = drm_vblank_count_and_time(dev, pipe, &now);
1718 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1719 if (e->pipe != pipe)
1721 if ((seq - e->event.sequence) > (1<<23))
1724 DRM_DEBUG("vblank event on %d, current %d\n",
1725 e->event.sequence, seq);
1727 list_del(&e->base.link);
1728 drm_vblank_put(dev, pipe);
1729 send_vblank_event(dev, e, seq, &now);
1732 trace_drm_vblank_event(pipe, seq);
1736 * drm_handle_vblank - handle a vblank event
1738 * @pipe: index of CRTC where this event occurred
1740 * Drivers should call this routine in their vblank interrupt handlers to
1741 * update the vblank counter and send any signals that may be pending.
1743 * This is the legacy version of drm_crtc_handle_vblank().
1745 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1747 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1748 unsigned long irqflags;
1750 if (WARN_ON_ONCE(!dev->num_crtcs))
1753 if (WARN_ON(pipe >= dev->num_crtcs))
1756 spin_lock_irqsave(&dev->event_lock, irqflags);
1758 /* Need timestamp lock to prevent concurrent execution with
1759 * vblank enable/disable, as this would cause inconsistent
1760 * or corrupted timestamps and vblank counts.
1762 spin_lock(&dev->vblank_time_lock);
1764 /* Vblank irq handling disabled. Nothing to do. */
1765 if (!vblank->enabled) {
1766 spin_unlock(&dev->vblank_time_lock);
1767 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1771 drm_update_vblank_count(dev, pipe, DRM_CALLED_FROM_VBLIRQ);
1773 spin_unlock(&dev->vblank_time_lock);
1775 wake_up(&vblank->queue);
1776 drm_handle_vblank_events(dev, pipe);
1778 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1782 EXPORT_SYMBOL(drm_handle_vblank);
1785 * drm_crtc_handle_vblank - handle a vblank event
1786 * @crtc: where this event occurred
1788 * Drivers should call this routine in their vblank interrupt handlers to
1789 * update the vblank counter and send any signals that may be pending.
1791 * This is the native KMS version of drm_handle_vblank().
1794 * True if the event was successfully handled, false on failure.
1796 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1798 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1800 EXPORT_SYMBOL(drm_crtc_handle_vblank);
1803 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1805 * @pipe: CRTC for which to read the counter
1807 * Drivers can plug this into the .get_vblank_counter() function if
1808 * there is no useable hardware frame counter available.
1813 u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
1817 EXPORT_SYMBOL(drm_vblank_no_hw_counter);