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 /* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
48 #define DRM_TIMESTAMP_MAXRETRIES 3
50 /* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
53 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
56 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
57 struct timeval *tvblank, unsigned flags);
59 static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
62 * Default to use monotonic timestamps for wait-for-vblank and page-flip
65 unsigned int drm_timestamp_monotonic = 1;
67 static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
69 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
70 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
71 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
72 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
73 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
74 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
76 static void store_vblank(struct drm_device *dev, unsigned int pipe,
78 struct timeval *t_vblank, u32 last)
80 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
82 assert_spin_locked(&dev->vblank_time_lock);
86 write_seqlock(&vblank->seqlock);
87 vblank->time = *t_vblank;
88 vblank->count += vblank_count_inc;
89 write_sequnlock(&vblank->seqlock);
93 * "No hw counter" fallback implementation of .get_vblank_counter() hook,
94 * if there is no useable hardware frame counter available.
96 static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
98 WARN_ON_ONCE(dev->max_vblank_count != 0);
102 static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
104 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
105 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
107 if (crtc->funcs->get_vblank_counter)
108 return crtc->funcs->get_vblank_counter(crtc);
111 if (dev->driver->get_vblank_counter)
112 return dev->driver->get_vblank_counter(dev, pipe);
114 return drm_vblank_no_hw_counter(dev, pipe);
118 * Reset the stored timestamp for the current vblank count to correspond
119 * to the last vblank occurred.
121 * Only to be called from drm_crtc_vblank_on().
123 * Note: caller must hold &drm_device.vbl_lock since this reads & writes
124 * device vblank fields.
126 static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
130 struct timeval t_vblank;
131 int count = DRM_TIMESTAMP_MAXRETRIES;
133 spin_lock(&dev->vblank_time_lock);
136 * sample the current counter to avoid random jumps
137 * when drm_vblank_enable() applies the diff
140 cur_vblank = __get_vblank_counter(dev, pipe);
141 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
142 } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
145 * Only reinitialize corresponding vblank timestamp if high-precision query
146 * available and didn't fail. Otherwise reinitialize delayed at next vblank
147 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
150 t_vblank = (struct timeval) {0, 0};
153 * +1 to make sure user will never see the same
154 * vblank counter value before and after a modeset
156 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
158 spin_unlock(&dev->vblank_time_lock);
162 * Call back into the driver to update the appropriate vblank counter
163 * (specified by @pipe). Deal with wraparound, if it occurred, and
164 * update the last read value so we can deal with wraparound on the next
167 * Only necessary when going from off->on, to account for frames we
168 * didn't get an interrupt for.
170 * Note: caller must hold &drm_device.vbl_lock since this reads & writes
171 * device vblank fields.
173 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
176 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
177 u32 cur_vblank, diff;
179 struct timeval t_vblank;
180 int count = DRM_TIMESTAMP_MAXRETRIES;
181 int framedur_ns = vblank->framedur_ns;
184 * Interrupts were disabled prior to this call, so deal with counter
186 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
187 * here if the register is small or we had vblank interrupts off for
190 * We repeat the hardware vblank counter & timestamp query until
191 * we get consistent results. This to prevent races between gpu
192 * updating its hardware counter while we are retrieving the
193 * corresponding vblank timestamp.
196 cur_vblank = __get_vblank_counter(dev, pipe);
197 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
198 } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
200 if (dev->max_vblank_count != 0) {
201 /* trust the hw counter when it's around */
202 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
203 } else if (rc && framedur_ns) {
204 const struct timeval *t_old;
207 t_old = &vblank->time;
208 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
211 * Figure out how many vblanks we've missed based
212 * on the difference in the timestamps and the
213 * frame/field duration.
215 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
217 if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
218 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
219 " diff_ns = %lld, framedur_ns = %d)\n",
220 pipe, (long long) diff_ns, framedur_ns);
222 /* some kind of default for drivers w/o accurate vbl timestamping */
223 diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
227 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
228 * interval? If so then vblank irqs keep running and it will likely
229 * happen that the hardware vblank counter is not trustworthy as it
230 * might reset at some point in that interval and vblank timestamps
231 * are not trustworthy either in that interval. Iow. this can result
232 * in a bogus diff >> 1 which must be avoided as it would cause
233 * random large forward jumps of the software vblank counter.
235 if (diff > 1 && (vblank->inmodeset & 0x2)) {
236 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
237 " due to pre-modeset.\n", pipe, diff);
241 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
242 " current=%u, diff=%u, hw=%u hw_last=%u\n",
243 pipe, vblank->count, diff, cur_vblank, vblank->last);
246 WARN_ON_ONCE(cur_vblank != vblank->last);
251 * Only reinitialize corresponding vblank timestamp if high-precision query
252 * available and didn't fail, or we were called from the vblank interrupt.
253 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
254 * for now, to mark the vblanktimestamp as invalid.
256 if (!rc && (flags & DRM_CALLED_FROM_VBLIRQ) == 0)
257 t_vblank = (struct timeval) {0, 0};
259 store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
262 static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
264 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
266 if (WARN_ON(pipe >= dev->num_crtcs))
269 return vblank->count;
273 * drm_accurate_vblank_count - retrieve the master vblank counter
274 * @crtc: which counter to retrieve
276 * This function is similar to @drm_crtc_vblank_count but this
277 * function interpolates to handle a race with vblank irq's.
279 * This is mostly useful for hardware that can obtain the scanout
280 * position, but doesn't have a frame counter.
282 u32 drm_accurate_vblank_count(struct drm_crtc *crtc)
284 struct drm_device *dev = crtc->dev;
285 unsigned int pipe = drm_crtc_index(crtc);
289 WARN(!dev->driver->get_vblank_timestamp,
290 "This function requires support for accurate vblank timestamps.");
292 spin_lock_irqsave(&dev->vblank_time_lock, flags);
294 drm_update_vblank_count(dev, pipe, 0);
295 vblank = drm_vblank_count(dev, pipe);
297 spin_unlock_irqrestore(&dev->vblank_time_lock, flags);
301 EXPORT_SYMBOL(drm_accurate_vblank_count);
303 static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
305 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
306 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
308 if (crtc->funcs->disable_vblank) {
309 crtc->funcs->disable_vblank(crtc);
314 dev->driver->disable_vblank(dev, pipe);
318 * Disable vblank irq's on crtc, make sure that last vblank count
319 * of hardware and corresponding consistent software vblank counter
320 * are preserved, even if there are any spurious vblank irq's after
323 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
325 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
326 unsigned long irqflags;
328 assert_spin_locked(&dev->vbl_lock);
330 /* Prevent vblank irq processing while disabling vblank irqs,
331 * so no updates of timestamps or count can happen after we've
332 * disabled. Needed to prevent races in case of delayed irq's.
334 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
337 * Only disable vblank interrupts if they're enabled. This avoids
338 * calling the ->disable_vblank() operation in atomic context with the
339 * hardware potentially runtime suspended.
341 if (vblank->enabled) {
342 __disable_vblank(dev, pipe);
343 vblank->enabled = false;
347 * Always update the count and timestamp to maintain the
348 * appearance that the counter has been ticking all along until
349 * this time. This makes the count account for the entire time
350 * between drm_crtc_vblank_on() and drm_crtc_vblank_off().
352 drm_update_vblank_count(dev, pipe, 0);
354 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
357 static void vblank_disable_fn(unsigned long arg)
359 struct drm_vblank_crtc *vblank = (void *)arg;
360 struct drm_device *dev = vblank->dev;
361 unsigned int pipe = vblank->pipe;
362 unsigned long irqflags;
364 spin_lock_irqsave(&dev->vbl_lock, irqflags);
365 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
366 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
367 vblank_disable_and_save(dev, pipe);
369 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
373 * drm_vblank_cleanup - cleanup vblank support
376 * This function cleans up any resources allocated in drm_vblank_init.
378 void drm_vblank_cleanup(struct drm_device *dev)
382 /* Bail if the driver didn't call drm_vblank_init() */
383 if (dev->num_crtcs == 0)
386 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
387 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
389 WARN_ON(READ_ONCE(vblank->enabled) &&
390 drm_core_check_feature(dev, DRIVER_MODESET));
392 del_timer_sync(&vblank->disable_timer);
399 EXPORT_SYMBOL(drm_vblank_cleanup);
402 * drm_vblank_init - initialize vblank support
404 * @num_crtcs: number of CRTCs supported by @dev
406 * This function initializes vblank support for @num_crtcs display pipelines.
409 * Zero on success or a negative error code on failure.
411 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
416 spin_lock_init(&dev->vbl_lock);
417 spin_lock_init(&dev->vblank_time_lock);
419 dev->num_crtcs = num_crtcs;
421 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
425 for (i = 0; i < num_crtcs; i++) {
426 struct drm_vblank_crtc *vblank = &dev->vblank[i];
430 init_waitqueue_head(&vblank->queue);
431 setup_timer(&vblank->disable_timer, vblank_disable_fn,
432 (unsigned long)vblank);
433 seqlock_init(&vblank->seqlock);
436 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
438 /* Driver specific high-precision vblank timestamping supported? */
439 if (dev->driver->get_vblank_timestamp)
440 DRM_INFO("Driver supports precise vblank timestamp query.\n");
442 DRM_INFO("No driver support for vblank timestamp query.\n");
444 /* Must have precise timestamping for reliable vblank instant disable */
445 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
446 dev->vblank_disable_immediate = false;
447 DRM_INFO("Setting vblank_disable_immediate to false because "
448 "get_vblank_timestamp == NULL\n");
457 EXPORT_SYMBOL(drm_vblank_init);
460 * drm_irq_install - install IRQ handler
462 * @irq: IRQ number to install the handler for
464 * Initializes the IRQ related data. Installs the handler, calling the driver
465 * irq_preinstall() and irq_postinstall() functions before and after the
468 * This is the simplified helper interface provided for drivers with no special
469 * needs. Drivers which need to install interrupt handlers for multiple
470 * interrupts must instead set &drm_device.irq_enabled to signal the DRM core
471 * that vblank interrupts are available.
474 * Zero on success or a negative error code on failure.
476 int drm_irq_install(struct drm_device *dev, int irq)
479 unsigned long sh_flags = 0;
481 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
487 /* Driver must have been initialized */
488 if (!dev->dev_private)
491 if (dev->irq_enabled)
493 dev->irq_enabled = true;
495 DRM_DEBUG("irq=%d\n", irq);
497 /* Before installing handler */
498 if (dev->driver->irq_preinstall)
499 dev->driver->irq_preinstall(dev);
501 /* Install handler */
502 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
503 sh_flags = IRQF_SHARED;
505 ret = request_irq(irq, dev->driver->irq_handler,
506 sh_flags, dev->driver->name, dev);
509 dev->irq_enabled = false;
513 /* After installing handler */
514 if (dev->driver->irq_postinstall)
515 ret = dev->driver->irq_postinstall(dev);
518 dev->irq_enabled = false;
519 if (drm_core_check_feature(dev, DRIVER_LEGACY))
520 vga_client_register(dev->pdev, NULL, NULL, NULL);
528 EXPORT_SYMBOL(drm_irq_install);
531 * drm_irq_uninstall - uninstall the IRQ handler
534 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
535 * This should only be called by drivers which used drm_irq_install() to set up
536 * their interrupt handler. Other drivers must only reset
537 * &drm_device.irq_enabled to false.
539 * Note that for kernel modesetting drivers it is a bug if this function fails.
540 * The sanity checks are only to catch buggy user modesetting drivers which call
541 * the same function through an ioctl.
544 * Zero on success or a negative error code on failure.
546 int drm_irq_uninstall(struct drm_device *dev)
548 unsigned long irqflags;
552 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
555 irq_enabled = dev->irq_enabled;
556 dev->irq_enabled = false;
559 * Wake up any waiters so they don't hang. This is just to paper over
560 * issues for UMS drivers which aren't in full control of their
561 * vblank/irq handling. KMS drivers must ensure that vblanks are all
562 * disabled when uninstalling the irq handler.
564 if (dev->num_crtcs) {
565 spin_lock_irqsave(&dev->vbl_lock, irqflags);
566 for (i = 0; i < dev->num_crtcs; i++) {
567 struct drm_vblank_crtc *vblank = &dev->vblank[i];
569 if (!vblank->enabled)
572 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
574 vblank_disable_and_save(dev, i);
575 wake_up(&vblank->queue);
577 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
583 DRM_DEBUG("irq=%d\n", dev->irq);
585 if (drm_core_check_feature(dev, DRIVER_LEGACY))
586 vga_client_register(dev->pdev, NULL, NULL, NULL);
588 if (dev->driver->irq_uninstall)
589 dev->driver->irq_uninstall(dev);
591 free_irq(dev->irq, dev);
595 EXPORT_SYMBOL(drm_irq_uninstall);
597 int drm_legacy_irq_control(struct drm_device *dev, void *data,
598 struct drm_file *file_priv)
600 struct drm_control *ctl = data;
603 /* if we haven't irq we fallback for compatibility reasons -
604 * this used to be a separate function in drm_dma.h
607 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
609 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
611 /* UMS was only ever supported on pci devices. */
612 if (WARN_ON(!dev->pdev))
616 case DRM_INST_HANDLER:
617 irq = dev->pdev->irq;
619 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
622 mutex_lock(&dev->struct_mutex);
623 ret = drm_irq_install(dev, irq);
624 mutex_unlock(&dev->struct_mutex);
627 case DRM_UNINST_HANDLER:
628 mutex_lock(&dev->struct_mutex);
629 ret = drm_irq_uninstall(dev);
630 mutex_unlock(&dev->struct_mutex);
639 * drm_calc_timestamping_constants - calculate vblank timestamp constants
640 * @crtc: drm_crtc whose timestamp constants should be updated.
641 * @mode: display mode containing the scanout timings
643 * Calculate and store various constants which are later
644 * needed by vblank and swap-completion timestamping, e.g,
645 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
646 * derived from CRTC's true scanout timing, so they take
647 * things like panel scaling or other adjustments into account.
649 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
650 const struct drm_display_mode *mode)
652 struct drm_device *dev = crtc->dev;
653 unsigned int pipe = drm_crtc_index(crtc);
654 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
655 int linedur_ns = 0, framedur_ns = 0;
656 int dotclock = mode->crtc_clock;
661 if (WARN_ON(pipe >= dev->num_crtcs))
664 /* Valid dotclock? */
666 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
669 * Convert scanline length in pixels and video
670 * dot clock to line duration and frame duration
673 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
674 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
677 * Fields of interlaced scanout modes are only half a frame duration.
679 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
682 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
685 vblank->linedur_ns = linedur_ns;
686 vblank->framedur_ns = framedur_ns;
688 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
689 crtc->base.id, mode->crtc_htotal,
690 mode->crtc_vtotal, mode->crtc_vdisplay);
691 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
692 crtc->base.id, dotclock, framedur_ns, linedur_ns);
694 EXPORT_SYMBOL(drm_calc_timestamping_constants);
697 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
699 * @pipe: index of CRTC whose vblank timestamp to retrieve
700 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
701 * On return contains true maximum error of timestamp
702 * @vblank_time: Pointer to struct timeval which should receive the timestamp
703 * @flags: Flags to pass to driver:
705 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
706 * @mode: mode which defines the scanout timings
708 * Implements calculation of exact vblank timestamps from given drm_display_mode
709 * timings and current video scanout position of a CRTC. This can be called from
710 * within get_vblank_timestamp() implementation of a kms driver to implement the
711 * actual timestamping.
713 * Should return timestamps conforming to the OML_sync_control OpenML
714 * extension specification. The timestamp corresponds to the end of
715 * the vblank interval, aka start of scanout of topmost-leftmost display
716 * pixel in the following video frame.
718 * Requires support for optional dev->driver->get_scanout_position()
719 * in kms driver, plus a bit of setup code to provide a drm_display_mode
720 * that corresponds to the true scanout timing.
722 * The current implementation only handles standard video modes. It
723 * returns as no operation if a doublescan or interlaced video mode is
724 * active. Higher level code is expected to handle this.
728 * Returns true on success, and false on failure, i.e. when no accurate
729 * timestamp could be acquired.
731 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
734 struct timeval *vblank_time,
736 const struct drm_display_mode *mode)
738 struct timeval tv_etime;
739 ktime_t stime, etime;
740 unsigned int vbl_status;
742 int delta_ns, duration_ns;
744 if (pipe >= dev->num_crtcs) {
745 DRM_ERROR("Invalid crtc %u\n", pipe);
749 /* Scanout position query not supported? Should not happen. */
750 if (!dev->driver->get_scanout_position) {
751 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
755 /* If mode timing undefined, just return as no-op:
756 * Happens during initial modesetting of a crtc.
758 if (mode->crtc_clock == 0) {
759 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
763 /* Get current scanout position with system timestamp.
764 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
765 * if single query takes longer than max_error nanoseconds.
767 * This guarantees a tight bound on maximum error if
768 * code gets preempted or delayed for some reason.
770 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
772 * Get vertical and horizontal scanout position vpos, hpos,
773 * and bounding timestamps stime, etime, pre/post query.
775 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
780 /* Return as no-op if scanout query unsupported or failed. */
781 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
782 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
787 /* Compute uncertainty in timestamp of scanout position query. */
788 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
790 /* Accept result with < max_error nsecs timing uncertainty. */
791 if (duration_ns <= *max_error)
795 /* Noisy system timing? */
796 if (i == DRM_TIMESTAMP_MAXRETRIES) {
797 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
798 pipe, duration_ns/1000, *max_error/1000, i);
801 /* Return upper bound of timestamp precision error. */
802 *max_error = duration_ns;
804 /* Convert scanout position into elapsed time at raw_time query
805 * since start of scanout at first display scanline. delta_ns
806 * can be negative if start of scanout hasn't happened yet.
808 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
811 if (!drm_timestamp_monotonic)
812 etime = ktime_mono_to_real(etime);
814 /* save this only for debugging purposes */
815 tv_etime = ktime_to_timeval(etime);
816 /* Subtract time delta from raw timestamp to get final
817 * vblank_time timestamp for end of vblank.
819 etime = ktime_sub_ns(etime, delta_ns);
820 *vblank_time = ktime_to_timeval(etime);
822 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
823 pipe, vbl_status, hpos, vpos,
824 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
825 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
826 duration_ns/1000, i);
830 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
832 static struct timeval get_drm_timestamp(void)
836 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
837 return ktime_to_timeval(now);
841 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
844 * @pipe: index of CRTC whose vblank timestamp to retrieve
845 * @tvblank: Pointer to target struct timeval which should receive the timestamp
846 * @flags: Flags to pass to driver:
848 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
850 * Fetches the system timestamp corresponding to the time of the most recent
851 * vblank interval on specified CRTC. May call into kms-driver to
852 * compute the timestamp with a high-precision GPU specific method.
854 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
855 * call, i.e., it isn't very precisely locked to the true vblank.
858 * True if timestamp is considered to be very precise, false otherwise.
861 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
862 struct timeval *tvblank, unsigned flags)
866 /* Define requested maximum error on timestamps (nanoseconds). */
867 int max_error = (int) drm_timestamp_precision * 1000;
869 /* Query driver if possible and precision timestamping enabled. */
870 if (dev->driver->get_vblank_timestamp && (max_error > 0))
871 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
874 /* GPU high precision timestamp query unsupported or failed.
875 * Return current monotonic/gettimeofday timestamp as best estimate.
878 *tvblank = get_drm_timestamp();
884 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
885 * @crtc: which counter to retrieve
887 * Fetches the "cooked" vblank count value that represents the number of
888 * vblank events since the system was booted, including lost events due to
889 * modesetting activity.
892 * The software vblank counter.
894 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
896 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
898 EXPORT_SYMBOL(drm_crtc_vblank_count);
901 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
902 * system timestamp corresponding to that vblank counter value.
904 * @pipe: index of CRTC whose counter to retrieve
905 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
907 * Fetches the "cooked" vblank count value that represents the number of
908 * vblank events since the system was booted, including lost events due to
909 * modesetting activity. Returns corresponding system timestamp of the time
910 * of the vblank interval that corresponds to the current vblank counter value.
912 * This is the legacy version of drm_crtc_vblank_count_and_time().
914 static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
915 struct timeval *vblanktime)
917 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
921 if (WARN_ON(pipe >= dev->num_crtcs)) {
922 *vblanktime = (struct timeval) { 0 };
927 seq = read_seqbegin(&vblank->seqlock);
928 vblank_count = vblank->count;
929 *vblanktime = vblank->time;
930 } while (read_seqretry(&vblank->seqlock, seq));
936 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
937 * and the system timestamp corresponding to that vblank counter value
938 * @crtc: which counter to retrieve
939 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
941 * Fetches the "cooked" vblank count value that represents the number of
942 * vblank events since the system was booted, including lost events due to
943 * modesetting activity. Returns corresponding system timestamp of the time
944 * of the vblank interval that corresponds to the current vblank counter value.
946 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
947 struct timeval *vblanktime)
949 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
952 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
954 static void send_vblank_event(struct drm_device *dev,
955 struct drm_pending_vblank_event *e,
956 unsigned long seq, struct timeval *now)
958 e->event.sequence = seq;
959 e->event.tv_sec = now->tv_sec;
960 e->event.tv_usec = now->tv_usec;
962 trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe,
965 drm_send_event_locked(dev, &e->base);
969 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
970 * @crtc: the source CRTC of the vblank event
971 * @e: the event to send
973 * A lot of drivers need to generate vblank events for the very next vblank
974 * interrupt. For example when the page flip interrupt happens when the page
975 * flip gets armed, but not when it actually executes within the next vblank
976 * period. This helper function implements exactly the required vblank arming
979 * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an
980 * atomic commit must ensure that the next vblank happens at exactly the same
981 * time as the atomic commit is committed to the hardware. This function itself
982 * does **not** protect again the next vblank interrupt racing with either this
983 * function call or the atomic commit operation. A possible sequence could be:
985 * 1. Driver commits new hardware state into vblank-synchronized registers.
986 * 2. A vblank happens, committing the hardware state. Also the corresponding
987 * vblank interrupt is fired off and fully processed by the interrupt
989 * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
990 * 4. The event is only send out for the next vblank, which is wrong.
992 * An equivalent race can happen when the driver calls
993 * drm_crtc_arm_vblank_event() before writing out the new hardware state.
995 * The only way to make this work safely is to prevent the vblank from firing
996 * (and the hardware from committing anything else) until the entire atomic
997 * commit sequence has run to completion. If the hardware does not have such a
998 * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
999 * Instead drivers need to manually send out the event from their interrupt
1000 * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
1001 * possible race with the hardware committing the atomic update.
1003 * Caller must hold event lock. Caller must also hold a vblank reference for
1004 * the event @e, which will be dropped when the next vblank arrives.
1006 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
1007 struct drm_pending_vblank_event *e)
1009 struct drm_device *dev = crtc->dev;
1010 unsigned int pipe = drm_crtc_index(crtc);
1012 assert_spin_locked(&dev->event_lock);
1015 e->event.sequence = drm_vblank_count(dev, pipe);
1016 e->event.crtc_id = crtc->base.id;
1017 list_add_tail(&e->base.link, &dev->vblank_event_list);
1019 EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
1022 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1023 * @crtc: the source CRTC of the vblank event
1024 * @e: the event to send
1026 * Updates sequence # and timestamp on event for the most recently processed
1027 * vblank, and sends it to userspace. Caller must hold event lock.
1029 * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
1030 * situation, especially to send out events for atomic commit operations.
1032 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1033 struct drm_pending_vblank_event *e)
1035 struct drm_device *dev = crtc->dev;
1036 unsigned int seq, pipe = drm_crtc_index(crtc);
1039 if (dev->num_crtcs > 0) {
1040 seq = drm_vblank_count_and_time(dev, pipe, &now);
1044 now = get_drm_timestamp();
1047 e->event.crtc_id = crtc->base.id;
1048 send_vblank_event(dev, e, seq, &now);
1050 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1052 static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
1054 if (drm_core_check_feature(dev, DRIVER_MODESET)) {
1055 struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
1057 if (crtc->funcs->enable_vblank)
1058 return crtc->funcs->enable_vblank(crtc);
1061 return dev->driver->enable_vblank(dev, pipe);
1065 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1070 * Zero on success or a negative error code on failure.
1072 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1074 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1077 assert_spin_locked(&dev->vbl_lock);
1079 spin_lock(&dev->vblank_time_lock);
1081 if (!vblank->enabled) {
1083 * Enable vblank irqs under vblank_time_lock protection.
1084 * All vblank count & timestamp updates are held off
1085 * until we are done reinitializing master counter and
1086 * timestamps. Filtercode in drm_handle_vblank() will
1087 * prevent double-accounting of same vblank interval.
1089 ret = __enable_vblank(dev, pipe);
1090 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1092 atomic_dec(&vblank->refcount);
1094 drm_update_vblank_count(dev, pipe, 0);
1095 /* drm_update_vblank_count() includes a wmb so we just
1096 * need to ensure that the compiler emits the write
1097 * to mark the vblank as enabled after the call
1098 * to drm_update_vblank_count().
1100 WRITE_ONCE(vblank->enabled, true);
1104 spin_unlock(&dev->vblank_time_lock);
1110 * drm_vblank_get - get a reference count on vblank events
1112 * @pipe: index of CRTC to own
1114 * Acquire a reference count on vblank events to avoid having them disabled
1117 * This is the legacy version of drm_crtc_vblank_get().
1120 * Zero on success or a negative error code on failure.
1122 static int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1124 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1125 unsigned long irqflags;
1128 if (!dev->num_crtcs)
1131 if (WARN_ON(pipe >= dev->num_crtcs))
1134 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1135 /* Going from 0->1 means we have to enable interrupts again */
1136 if (atomic_add_return(1, &vblank->refcount) == 1) {
1137 ret = drm_vblank_enable(dev, pipe);
1139 if (!vblank->enabled) {
1140 atomic_dec(&vblank->refcount);
1144 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1150 * drm_crtc_vblank_get - get a reference count on vblank events
1151 * @crtc: which CRTC to own
1153 * Acquire a reference count on vblank events to avoid having them disabled
1157 * Zero on success or a negative error code on failure.
1159 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1161 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1163 EXPORT_SYMBOL(drm_crtc_vblank_get);
1166 * drm_vblank_put - release ownership of vblank events
1168 * @pipe: index of CRTC to release
1170 * Release ownership of a given vblank counter, turning off interrupts
1171 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1173 * This is the legacy version of drm_crtc_vblank_put().
1175 static void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1177 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1179 if (WARN_ON(pipe >= dev->num_crtcs))
1182 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1185 /* Last user schedules interrupt disable */
1186 if (atomic_dec_and_test(&vblank->refcount)) {
1187 if (drm_vblank_offdelay == 0)
1189 else if (drm_vblank_offdelay < 0)
1190 vblank_disable_fn((unsigned long)vblank);
1191 else if (!dev->vblank_disable_immediate)
1192 mod_timer(&vblank->disable_timer,
1193 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1198 * drm_crtc_vblank_put - give up ownership of vblank events
1199 * @crtc: which counter to give up
1201 * Release ownership of a given vblank counter, turning off interrupts
1202 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1204 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1206 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1208 EXPORT_SYMBOL(drm_crtc_vblank_put);
1211 * drm_wait_one_vblank - wait for one vblank
1215 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1216 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1217 * due to lack of driver support or because the crtc is off.
1219 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1221 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1225 if (WARN_ON(pipe >= dev->num_crtcs))
1228 ret = drm_vblank_get(dev, pipe);
1229 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1232 last = drm_vblank_count(dev, pipe);
1234 ret = wait_event_timeout(vblank->queue,
1235 last != drm_vblank_count(dev, pipe),
1236 msecs_to_jiffies(100));
1238 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1240 drm_vblank_put(dev, pipe);
1242 EXPORT_SYMBOL(drm_wait_one_vblank);
1245 * drm_crtc_wait_one_vblank - wait for one vblank
1248 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1249 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1250 * due to lack of driver support or because the crtc is off.
1252 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1254 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1256 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1259 * drm_crtc_vblank_off - disable vblank events on a CRTC
1260 * @crtc: CRTC in question
1262 * Drivers can use this function to shut down the vblank interrupt handling when
1263 * disabling a crtc. This function ensures that the latest vblank frame count is
1264 * stored so that drm_vblank_on can restore it again.
1266 * Drivers must use this function when the hardware vblank counter can get
1267 * reset, e.g. when suspending.
1269 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1271 struct drm_device *dev = crtc->dev;
1272 unsigned int pipe = drm_crtc_index(crtc);
1273 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1274 struct drm_pending_vblank_event *e, *t;
1276 unsigned long irqflags;
1279 if (WARN_ON(pipe >= dev->num_crtcs))
1282 spin_lock_irqsave(&dev->event_lock, irqflags);
1284 spin_lock(&dev->vbl_lock);
1285 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1286 pipe, vblank->enabled, vblank->inmodeset);
1288 /* Avoid redundant vblank disables without previous
1289 * drm_crtc_vblank_on(). */
1290 if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
1291 vblank_disable_and_save(dev, pipe);
1293 wake_up(&vblank->queue);
1296 * Prevent subsequent drm_vblank_get() from re-enabling
1297 * the vblank interrupt by bumping the refcount.
1299 if (!vblank->inmodeset) {
1300 atomic_inc(&vblank->refcount);
1301 vblank->inmodeset = 1;
1303 spin_unlock(&dev->vbl_lock);
1305 /* Send any queued vblank events, lest the natives grow disquiet */
1306 seq = drm_vblank_count_and_time(dev, pipe, &now);
1308 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1309 if (e->pipe != pipe)
1311 DRM_DEBUG("Sending premature vblank event on disable: "
1312 "wanted %u, current %u\n",
1313 e->event.sequence, seq);
1314 list_del(&e->base.link);
1315 drm_vblank_put(dev, pipe);
1316 send_vblank_event(dev, e, seq, &now);
1318 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1320 EXPORT_SYMBOL(drm_crtc_vblank_off);
1323 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1324 * @crtc: CRTC in question
1326 * Drivers can use this function to reset the vblank state to off at load time.
1327 * Drivers should use this together with the drm_crtc_vblank_off() and
1328 * drm_crtc_vblank_on() functions. The difference compared to
1329 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1330 * and hence doesn't need to call any driver hooks.
1332 void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1334 struct drm_device *dev = crtc->dev;
1335 unsigned long irqflags;
1336 unsigned int pipe = drm_crtc_index(crtc);
1337 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1339 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1341 * Prevent subsequent drm_vblank_get() from enabling the vblank
1342 * interrupt by bumping the refcount.
1344 if (!vblank->inmodeset) {
1345 atomic_inc(&vblank->refcount);
1346 vblank->inmodeset = 1;
1348 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1350 WARN_ON(!list_empty(&dev->vblank_event_list));
1352 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1355 * drm_crtc_vblank_on - enable vblank events on a CRTC
1356 * @crtc: CRTC in question
1358 * This functions restores the vblank interrupt state captured with
1359 * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and
1360 * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called
1361 * in driver load code to reflect the current hardware state of the crtc.
1363 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1365 struct drm_device *dev = crtc->dev;
1366 unsigned int pipe = drm_crtc_index(crtc);
1367 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1368 unsigned long irqflags;
1370 if (WARN_ON(pipe >= dev->num_crtcs))
1373 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1374 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1375 pipe, vblank->enabled, vblank->inmodeset);
1377 /* Drop our private "prevent drm_vblank_get" refcount */
1378 if (vblank->inmodeset) {
1379 atomic_dec(&vblank->refcount);
1380 vblank->inmodeset = 0;
1383 drm_reset_vblank_timestamp(dev, pipe);
1386 * re-enable interrupts if there are users left, or the
1387 * user wishes vblank interrupts to be enabled all the time.
1389 if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0)
1390 WARN_ON(drm_vblank_enable(dev, pipe));
1391 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1393 EXPORT_SYMBOL(drm_crtc_vblank_on);
1395 static void drm_legacy_vblank_pre_modeset(struct drm_device *dev,
1398 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1400 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1401 if (!dev->num_crtcs)
1404 if (WARN_ON(pipe >= dev->num_crtcs))
1408 * To avoid all the problems that might happen if interrupts
1409 * were enabled/disabled around or between these calls, we just
1410 * have the kernel take a reference on the CRTC (just once though
1411 * to avoid corrupting the count if multiple, mismatch calls occur),
1412 * so that interrupts remain enabled in the interim.
1414 if (!vblank->inmodeset) {
1415 vblank->inmodeset = 0x1;
1416 if (drm_vblank_get(dev, pipe) == 0)
1417 vblank->inmodeset |= 0x2;
1421 static void drm_legacy_vblank_post_modeset(struct drm_device *dev,
1424 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1425 unsigned long irqflags;
1427 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1428 if (!dev->num_crtcs)
1431 if (WARN_ON(pipe >= dev->num_crtcs))
1434 if (vblank->inmodeset) {
1435 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1436 drm_reset_vblank_timestamp(dev, pipe);
1437 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1439 if (vblank->inmodeset & 0x2)
1440 drm_vblank_put(dev, pipe);
1442 vblank->inmodeset = 0;
1446 int drm_legacy_modeset_ctl(struct drm_device *dev, void *data,
1447 struct drm_file *file_priv)
1449 struct drm_modeset_ctl *modeset = data;
1452 /* If drm_vblank_init() hasn't been called yet, just no-op */
1453 if (!dev->num_crtcs)
1456 /* KMS drivers handle this internally */
1457 if (!drm_core_check_feature(dev, DRIVER_LEGACY))
1460 pipe = modeset->crtc;
1461 if (pipe >= dev->num_crtcs)
1464 switch (modeset->cmd) {
1465 case _DRM_PRE_MODESET:
1466 drm_legacy_vblank_pre_modeset(dev, pipe);
1468 case _DRM_POST_MODESET:
1469 drm_legacy_vblank_post_modeset(dev, pipe);
1478 static inline bool vblank_passed(u32 seq, u32 ref)
1480 return (seq - ref) <= (1 << 23);
1483 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1484 union drm_wait_vblank *vblwait,
1485 struct drm_file *file_priv)
1487 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1488 struct drm_pending_vblank_event *e;
1490 unsigned long flags;
1494 e = kzalloc(sizeof(*e), GFP_KERNEL);
1501 e->event.base.type = DRM_EVENT_VBLANK;
1502 e->event.base.length = sizeof(e->event);
1503 e->event.user_data = vblwait->request.signal;
1505 spin_lock_irqsave(&dev->event_lock, flags);
1508 * drm_crtc_vblank_off() might have been called after we called
1509 * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
1510 * vblank disable, so no need for further locking. The reference from
1511 * drm_vblank_get() protects against vblank disable from another source.
1513 if (!READ_ONCE(vblank->enabled)) {
1518 ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
1524 seq = drm_vblank_count_and_time(dev, pipe, &now);
1526 DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n",
1527 vblwait->request.sequence, seq, pipe);
1529 trace_drm_vblank_event_queued(file_priv, pipe,
1530 vblwait->request.sequence);
1532 e->event.sequence = vblwait->request.sequence;
1533 if (vblank_passed(seq, vblwait->request.sequence)) {
1534 drm_vblank_put(dev, pipe);
1535 send_vblank_event(dev, e, seq, &now);
1536 vblwait->reply.sequence = seq;
1538 /* drm_handle_vblank_events will call drm_vblank_put */
1539 list_add_tail(&e->base.link, &dev->vblank_event_list);
1540 vblwait->reply.sequence = vblwait->request.sequence;
1543 spin_unlock_irqrestore(&dev->event_lock, flags);
1548 spin_unlock_irqrestore(&dev->event_lock, flags);
1551 drm_vblank_put(dev, pipe);
1555 static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait)
1557 if (vblwait->request.sequence)
1560 return _DRM_VBLANK_RELATIVE ==
1561 (vblwait->request.type & (_DRM_VBLANK_TYPES_MASK |
1563 _DRM_VBLANK_NEXTONMISS));
1569 * \param inode device inode.
1570 * \param file_priv DRM file private.
1571 * \param cmd command.
1572 * \param data user argument, pointing to a drm_wait_vblank structure.
1573 * \return zero on success or a negative number on failure.
1575 * This function enables the vblank interrupt on the pipe requested, then
1576 * sleeps waiting for the requested sequence number to occur, and drops
1577 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1578 * after a timeout with no further vblank waits scheduled).
1580 int drm_wait_vblank(struct drm_device *dev, void *data,
1581 struct drm_file *file_priv)
1583 struct drm_vblank_crtc *vblank;
1584 union drm_wait_vblank *vblwait = data;
1586 unsigned int flags, seq, pipe, high_pipe;
1588 if (!dev->irq_enabled)
1591 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1594 if (vblwait->request.type &
1595 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1596 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1597 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1598 vblwait->request.type,
1599 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1600 _DRM_VBLANK_HIGH_CRTC_MASK));
1604 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1605 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1607 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1609 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1610 if (pipe >= dev->num_crtcs)
1613 vblank = &dev->vblank[pipe];
1615 /* If the counter is currently enabled and accurate, short-circuit
1616 * queries to return the cached timestamp of the last vblank.
1618 if (dev->vblank_disable_immediate &&
1619 drm_wait_vblank_is_query(vblwait) &&
1620 READ_ONCE(vblank->enabled)) {
1623 vblwait->reply.sequence =
1624 drm_vblank_count_and_time(dev, pipe, &now);
1625 vblwait->reply.tval_sec = now.tv_sec;
1626 vblwait->reply.tval_usec = now.tv_usec;
1630 ret = drm_vblank_get(dev, pipe);
1632 DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret);
1635 seq = drm_vblank_count(dev, pipe);
1637 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1638 case _DRM_VBLANK_RELATIVE:
1639 vblwait->request.sequence += seq;
1640 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1641 case _DRM_VBLANK_ABSOLUTE:
1648 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1649 vblank_passed(seq, vblwait->request.sequence))
1650 vblwait->request.sequence = seq + 1;
1652 if (flags & _DRM_VBLANK_EVENT) {
1653 /* must hold on to the vblank ref until the event fires
1654 * drm_vblank_put will be called asynchronously
1656 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1659 if (vblwait->request.sequence != seq) {
1660 DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
1661 vblwait->request.sequence, pipe);
1662 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1663 vblank_passed(drm_vblank_count(dev, pipe),
1664 vblwait->request.sequence) ||
1665 !READ_ONCE(vblank->enabled));
1668 if (ret != -EINTR) {
1671 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1672 vblwait->reply.tval_sec = now.tv_sec;
1673 vblwait->reply.tval_usec = now.tv_usec;
1675 DRM_DEBUG("crtc %d returning %u to client\n",
1676 pipe, vblwait->reply.sequence);
1678 DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe);
1682 drm_vblank_put(dev, pipe);
1686 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1688 struct drm_pending_vblank_event *e, *t;
1692 assert_spin_locked(&dev->event_lock);
1694 seq = drm_vblank_count_and_time(dev, pipe, &now);
1696 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1697 if (e->pipe != pipe)
1699 if (!vblank_passed(seq, e->event.sequence))
1702 DRM_DEBUG("vblank event on %u, current %u\n",
1703 e->event.sequence, seq);
1705 list_del(&e->base.link);
1706 drm_vblank_put(dev, pipe);
1707 send_vblank_event(dev, e, seq, &now);
1710 trace_drm_vblank_event(pipe, seq);
1714 * drm_handle_vblank - handle a vblank event
1716 * @pipe: index of CRTC where this event occurred
1718 * Drivers should call this routine in their vblank interrupt handlers to
1719 * update the vblank counter and send any signals that may be pending.
1721 * This is the legacy version of drm_crtc_handle_vblank().
1723 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1725 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1726 unsigned long irqflags;
1729 if (WARN_ON_ONCE(!dev->num_crtcs))
1732 if (WARN_ON(pipe >= dev->num_crtcs))
1735 spin_lock_irqsave(&dev->event_lock, irqflags);
1737 /* Need timestamp lock to prevent concurrent execution with
1738 * vblank enable/disable, as this would cause inconsistent
1739 * or corrupted timestamps and vblank counts.
1741 spin_lock(&dev->vblank_time_lock);
1743 /* Vblank irq handling disabled. Nothing to do. */
1744 if (!vblank->enabled) {
1745 spin_unlock(&dev->vblank_time_lock);
1746 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1750 drm_update_vblank_count(dev, pipe, DRM_CALLED_FROM_VBLIRQ);
1752 spin_unlock(&dev->vblank_time_lock);
1754 wake_up(&vblank->queue);
1756 /* With instant-off, we defer disabling the interrupt until after
1757 * we finish processing the following vblank after all events have
1758 * been signaled. The disable has to be last (after
1759 * drm_handle_vblank_events) so that the timestamp is always accurate.
1761 disable_irq = (dev->vblank_disable_immediate &&
1762 drm_vblank_offdelay > 0 &&
1763 !atomic_read(&vblank->refcount));
1765 drm_handle_vblank_events(dev, pipe);
1767 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1770 vblank_disable_fn((unsigned long)vblank);
1774 EXPORT_SYMBOL(drm_handle_vblank);
1777 * drm_crtc_handle_vblank - handle a vblank event
1778 * @crtc: where this event occurred
1780 * Drivers should call this routine in their vblank interrupt handlers to
1781 * update the vblank counter and send any signals that may be pending.
1783 * This is the native KMS version of drm_handle_vblank().
1786 * True if the event was successfully handled, false on failure.
1788 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1790 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1792 EXPORT_SYMBOL(drm_crtc_handle_vblank);