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 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
95 * @pipe: index of CRTC for which to reset the timestamp
97 * Reset the stored timestamp for the current vblank count to correspond
98 * to the last vblank occurred.
100 * Only to be called from drm_vblank_on().
102 * Note: caller must hold dev->vbl_lock since this reads & writes
103 * device vblank fields.
105 static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
109 struct timeval t_vblank;
110 int count = DRM_TIMESTAMP_MAXRETRIES;
112 spin_lock(&dev->vblank_time_lock);
115 * sample the current counter to avoid random jumps
116 * when drm_vblank_enable() applies the diff
119 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
120 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
121 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
124 * Only reinitialize corresponding vblank timestamp if high-precision query
125 * available and didn't fail. Otherwise reinitialize delayed at next vblank
126 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
129 t_vblank = (struct timeval) {0, 0};
132 * +1 to make sure user will never see the same
133 * vblank counter value before and after a modeset
135 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
137 spin_unlock(&dev->vblank_time_lock);
141 * drm_update_vblank_count - update the master vblank counter
143 * @pipe: counter to update
145 * Call back into the driver to update the appropriate vblank counter
146 * (specified by @pipe). Deal with wraparound, if it occurred, and
147 * update the last read value so we can deal with wraparound on the next
150 * Only necessary when going from off->on, to account for frames we
151 * didn't get an interrupt for.
153 * Note: caller must hold dev->vbl_lock since this reads & writes
154 * device vblank fields.
156 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
159 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
160 u32 cur_vblank, diff;
162 struct timeval t_vblank;
163 int count = DRM_TIMESTAMP_MAXRETRIES;
164 int framedur_ns = vblank->framedur_ns;
167 * Interrupts were disabled prior to this call, so deal with counter
169 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
170 * here if the register is small or we had vblank interrupts off for
173 * We repeat the hardware vblank counter & timestamp query until
174 * we get consistent results. This to prevent races between gpu
175 * updating its hardware counter while we are retrieving the
176 * corresponding vblank timestamp.
179 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
180 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
181 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
183 if (dev->max_vblank_count != 0) {
184 /* trust the hw counter when it's around */
185 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
186 } else if (rc && framedur_ns) {
187 const struct timeval *t_old;
190 t_old = &vblank->time;
191 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
194 * Figure out how many vblanks we've missed based
195 * on the difference in the timestamps and the
196 * frame/field duration.
198 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
200 if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
201 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
202 " diff_ns = %lld, framedur_ns = %d)\n",
203 pipe, (long long) diff_ns, framedur_ns);
205 /* some kind of default for drivers w/o accurate vbl timestamping */
206 diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
210 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
211 * interval? If so then vblank irqs keep running and it will likely
212 * happen that the hardware vblank counter is not trustworthy as it
213 * might reset at some point in that interval and vblank timestamps
214 * are not trustworthy either in that interval. Iow. this can result
215 * in a bogus diff >> 1 which must be avoided as it would cause
216 * random large forward jumps of the software vblank counter.
218 if (diff > 1 && (vblank->inmodeset & 0x2)) {
219 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
220 " due to pre-modeset.\n", pipe, diff);
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 * drm_accurate_vblank_count - retrieve the master vblank counter
247 * @crtc: which counter to retrieve
249 * This function is similar to @drm_crtc_vblank_count but this
250 * function interpolates to handle a race with vblank irq's.
252 * This is mostly useful for hardware that can obtain the scanout
253 * position, but doesn't have a frame counter.
255 u32 drm_accurate_vblank_count(struct drm_crtc *crtc)
257 struct drm_device *dev = crtc->dev;
258 unsigned int pipe = drm_crtc_index(crtc);
262 WARN(!dev->driver->get_vblank_timestamp,
263 "This function requires support for accurate vblank timestamps.");
265 spin_lock_irqsave(&dev->vblank_time_lock, flags);
267 drm_update_vblank_count(dev, pipe, 0);
268 vblank = drm_vblank_count(dev, pipe);
270 spin_unlock_irqrestore(&dev->vblank_time_lock, flags);
274 EXPORT_SYMBOL(drm_accurate_vblank_count);
277 * Disable vblank irq's on crtc, make sure that last vblank count
278 * of hardware and corresponding consistent software vblank counter
279 * are preserved, even if there are any spurious vblank irq's after
282 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
284 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
285 unsigned long irqflags;
287 /* Prevent vblank irq processing while disabling vblank irqs,
288 * so no updates of timestamps or count can happen after we've
289 * disabled. Needed to prevent races in case of delayed irq's.
291 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
294 * Only disable vblank interrupts if they're enabled. This avoids
295 * calling the ->disable_vblank() operation in atomic context with the
296 * hardware potentially runtime suspended.
298 if (vblank->enabled) {
299 dev->driver->disable_vblank(dev, pipe);
300 vblank->enabled = false;
304 * Always update the count and timestamp to maintain the
305 * appearance that the counter has been ticking all along until
306 * this time. This makes the count account for the entire time
307 * between drm_vblank_on() and drm_vblank_off().
309 drm_update_vblank_count(dev, pipe, 0);
311 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
314 static void vblank_disable_fn(unsigned long arg)
316 struct drm_vblank_crtc *vblank = (void *)arg;
317 struct drm_device *dev = vblank->dev;
318 unsigned int pipe = vblank->pipe;
319 unsigned long irqflags;
321 spin_lock_irqsave(&dev->vbl_lock, irqflags);
322 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
323 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
324 vblank_disable_and_save(dev, pipe);
326 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
330 * drm_vblank_cleanup - cleanup vblank support
333 * This function cleans up any resources allocated in drm_vblank_init.
335 void drm_vblank_cleanup(struct drm_device *dev)
339 /* Bail if the driver didn't call drm_vblank_init() */
340 if (dev->num_crtcs == 0)
343 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
344 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
346 WARN_ON(vblank->enabled &&
347 drm_core_check_feature(dev, DRIVER_MODESET));
349 del_timer_sync(&vblank->disable_timer);
356 EXPORT_SYMBOL(drm_vblank_cleanup);
359 * drm_vblank_init - initialize vblank support
361 * @num_crtcs: number of CRTCs supported by @dev
363 * This function initializes vblank support for @num_crtcs display pipelines.
366 * Zero on success or a negative error code on failure.
368 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
373 spin_lock_init(&dev->vbl_lock);
374 spin_lock_init(&dev->vblank_time_lock);
376 dev->num_crtcs = num_crtcs;
378 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
382 for (i = 0; i < num_crtcs; i++) {
383 struct drm_vblank_crtc *vblank = &dev->vblank[i];
387 init_waitqueue_head(&vblank->queue);
388 setup_timer(&vblank->disable_timer, vblank_disable_fn,
389 (unsigned long)vblank);
390 seqlock_init(&vblank->seqlock);
393 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
395 /* Driver specific high-precision vblank timestamping supported? */
396 if (dev->driver->get_vblank_timestamp)
397 DRM_INFO("Driver supports precise vblank timestamp query.\n");
399 DRM_INFO("No driver support for vblank timestamp query.\n");
401 /* Must have precise timestamping for reliable vblank instant disable */
402 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
403 dev->vblank_disable_immediate = false;
404 DRM_INFO("Setting vblank_disable_immediate to false because "
405 "get_vblank_timestamp == NULL\n");
414 EXPORT_SYMBOL(drm_vblank_init);
416 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
418 struct drm_device *dev = cookie;
420 if (dev->driver->vgaarb_irq) {
421 dev->driver->vgaarb_irq(dev, state);
425 if (!dev->irq_enabled)
429 if (dev->driver->irq_uninstall)
430 dev->driver->irq_uninstall(dev);
432 if (dev->driver->irq_preinstall)
433 dev->driver->irq_preinstall(dev);
434 if (dev->driver->irq_postinstall)
435 dev->driver->irq_postinstall(dev);
440 * drm_irq_install - install IRQ handler
442 * @irq: IRQ number to install the handler for
444 * Initializes the IRQ related data. Installs the handler, calling the driver
445 * irq_preinstall() and irq_postinstall() functions before and after the
448 * This is the simplified helper interface provided for drivers with no special
449 * needs. Drivers which need to install interrupt handlers for multiple
450 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
451 * that vblank interrupts are available.
454 * Zero on success or a negative error code on failure.
456 int drm_irq_install(struct drm_device *dev, int irq)
459 unsigned long sh_flags = 0;
461 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
467 /* Driver must have been initialized */
468 if (!dev->dev_private)
471 if (dev->irq_enabled)
473 dev->irq_enabled = true;
475 DRM_DEBUG("irq=%d\n", irq);
477 /* Before installing handler */
478 if (dev->driver->irq_preinstall)
479 dev->driver->irq_preinstall(dev);
481 /* Install handler */
482 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
483 sh_flags = IRQF_SHARED;
485 ret = request_irq(irq, dev->driver->irq_handler,
486 sh_flags, dev->driver->name, dev);
489 dev->irq_enabled = false;
493 if (!drm_core_check_feature(dev, DRIVER_MODESET))
494 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
496 /* After installing handler */
497 if (dev->driver->irq_postinstall)
498 ret = dev->driver->irq_postinstall(dev);
501 dev->irq_enabled = false;
502 if (!drm_core_check_feature(dev, DRIVER_MODESET))
503 vga_client_register(dev->pdev, NULL, NULL, NULL);
511 EXPORT_SYMBOL(drm_irq_install);
514 * drm_irq_uninstall - uninstall the IRQ handler
517 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
518 * This should only be called by drivers which used drm_irq_install() to set up
519 * their interrupt handler. Other drivers must only reset
520 * drm_device->irq_enabled to false.
522 * Note that for kernel modesetting drivers it is a bug if this function fails.
523 * The sanity checks are only to catch buggy user modesetting drivers which call
524 * the same function through an ioctl.
527 * Zero on success or a negative error code on failure.
529 int drm_irq_uninstall(struct drm_device *dev)
531 unsigned long irqflags;
535 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
538 irq_enabled = dev->irq_enabled;
539 dev->irq_enabled = false;
542 * Wake up any waiters so they don't hang. This is just to paper over
543 * isssues for UMS drivers which aren't in full control of their
544 * vblank/irq handling. KMS drivers must ensure that vblanks are all
545 * disabled when uninstalling the irq handler.
547 if (dev->num_crtcs) {
548 spin_lock_irqsave(&dev->vbl_lock, irqflags);
549 for (i = 0; i < dev->num_crtcs; i++) {
550 struct drm_vblank_crtc *vblank = &dev->vblank[i];
552 if (!vblank->enabled)
555 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
557 vblank_disable_and_save(dev, i);
558 wake_up(&vblank->queue);
560 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
566 DRM_DEBUG("irq=%d\n", dev->irq);
568 if (!drm_core_check_feature(dev, DRIVER_MODESET))
569 vga_client_register(dev->pdev, NULL, NULL, NULL);
571 if (dev->driver->irq_uninstall)
572 dev->driver->irq_uninstall(dev);
574 free_irq(dev->irq, dev);
578 EXPORT_SYMBOL(drm_irq_uninstall);
583 * \param inode device inode.
584 * \param file_priv DRM file private.
585 * \param cmd command.
586 * \param arg user argument, pointing to a drm_control structure.
587 * \return zero on success or a negative number on failure.
589 * Calls irq_install() or irq_uninstall() according to \p arg.
591 int drm_control(struct drm_device *dev, void *data,
592 struct drm_file *file_priv)
594 struct drm_control *ctl = data;
597 /* if we haven't irq we fallback for compatibility reasons -
598 * this used to be a separate function in drm_dma.h
601 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
603 if (drm_core_check_feature(dev, DRIVER_MODESET))
605 /* UMS was only ever support on pci devices. */
606 if (WARN_ON(!dev->pdev))
610 case DRM_INST_HANDLER:
611 irq = dev->pdev->irq;
613 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
616 mutex_lock(&dev->struct_mutex);
617 ret = drm_irq_install(dev, irq);
618 mutex_unlock(&dev->struct_mutex);
621 case DRM_UNINST_HANDLER:
622 mutex_lock(&dev->struct_mutex);
623 ret = drm_irq_uninstall(dev);
624 mutex_unlock(&dev->struct_mutex);
633 * drm_calc_timestamping_constants - calculate vblank timestamp constants
634 * @crtc: drm_crtc whose timestamp constants should be updated.
635 * @mode: display mode containing the scanout timings
637 * Calculate and store various constants which are later
638 * needed by vblank and swap-completion timestamping, e.g,
639 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
640 * derived from CRTC's true scanout timing, so they take
641 * things like panel scaling or other adjustments into account.
643 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
644 const struct drm_display_mode *mode)
646 struct drm_device *dev = crtc->dev;
647 unsigned int pipe = drm_crtc_index(crtc);
648 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
649 int linedur_ns = 0, framedur_ns = 0;
650 int dotclock = mode->crtc_clock;
655 if (WARN_ON(pipe >= dev->num_crtcs))
658 /* Valid dotclock? */
660 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
663 * Convert scanline length in pixels and video
664 * dot clock to line duration and frame duration
667 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
668 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
671 * Fields of interlaced scanout modes are only half a frame duration.
673 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
676 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
679 vblank->linedur_ns = linedur_ns;
680 vblank->framedur_ns = framedur_ns;
682 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
683 crtc->base.id, mode->crtc_htotal,
684 mode->crtc_vtotal, mode->crtc_vdisplay);
685 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
686 crtc->base.id, dotclock, framedur_ns, linedur_ns);
688 EXPORT_SYMBOL(drm_calc_timestamping_constants);
691 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
693 * @pipe: index of CRTC whose vblank timestamp to retrieve
694 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
695 * On return contains true maximum error of timestamp
696 * @vblank_time: Pointer to struct timeval which should receive the timestamp
697 * @flags: Flags to pass to driver:
699 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
700 * @mode: mode which defines the scanout timings
702 * Implements calculation of exact vblank timestamps from given drm_display_mode
703 * timings and current video scanout position of a CRTC. This can be called from
704 * within get_vblank_timestamp() implementation of a kms driver to implement the
705 * actual timestamping.
707 * Should return timestamps conforming to the OML_sync_control OpenML
708 * extension specification. The timestamp corresponds to the end of
709 * the vblank interval, aka start of scanout of topmost-leftmost display
710 * pixel in the following video frame.
712 * Requires support for optional dev->driver->get_scanout_position()
713 * in kms driver, plus a bit of setup code to provide a drm_display_mode
714 * that corresponds to the true scanout timing.
716 * The current implementation only handles standard video modes. It
717 * returns as no operation if a doublescan or interlaced video mode is
718 * active. Higher level code is expected to handle this.
721 * Negative value on error, failure or if not supported in current
724 * -EINVAL - Invalid CRTC.
725 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
726 * -ENOTSUPP - Function not supported in current display mode.
727 * -EIO - Failed, e.g., due to failed scanout position query.
729 * Returns or'ed positive status flags on success:
731 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
732 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
735 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
738 struct timeval *vblank_time,
740 const struct drm_display_mode *mode)
742 struct timeval tv_etime;
743 ktime_t stime, etime;
744 unsigned int vbl_status;
745 int ret = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
747 int delta_ns, duration_ns;
749 if (pipe >= dev->num_crtcs) {
750 DRM_ERROR("Invalid crtc %u\n", pipe);
754 /* Scanout position query not supported? Should not happen. */
755 if (!dev->driver->get_scanout_position) {
756 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
760 /* If mode timing undefined, just return as no-op:
761 * Happens during initial modesetting of a crtc.
763 if (mode->crtc_clock == 0) {
764 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
768 /* Get current scanout position with system timestamp.
769 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
770 * if single query takes longer than max_error nanoseconds.
772 * This guarantees a tight bound on maximum error if
773 * code gets preempted or delayed for some reason.
775 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
777 * Get vertical and horizontal scanout position vpos, hpos,
778 * and bounding timestamps stime, etime, pre/post query.
780 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
785 /* Return as no-op if scanout query unsupported or failed. */
786 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
787 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
792 /* Compute uncertainty in timestamp of scanout position query. */
793 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
795 /* Accept result with < max_error nsecs timing uncertainty. */
796 if (duration_ns <= *max_error)
800 /* Noisy system timing? */
801 if (i == DRM_TIMESTAMP_MAXRETRIES) {
802 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
803 pipe, duration_ns/1000, *max_error/1000, i);
806 /* Return upper bound of timestamp precision error. */
807 *max_error = duration_ns;
809 /* Check if in vblank area:
810 * vpos is >=0 in video scanout area, but negative
811 * within vblank area, counting down the number of lines until
814 if (vbl_status & DRM_SCANOUTPOS_IN_VBLANK)
815 ret |= DRM_VBLANKTIME_IN_VBLANK;
817 /* Convert scanout position into elapsed time at raw_time query
818 * since start of scanout at first display scanline. delta_ns
819 * can be negative if start of scanout hasn't happened yet.
821 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
824 if (!drm_timestamp_monotonic)
825 etime = ktime_mono_to_real(etime);
827 /* save this only for debugging purposes */
828 tv_etime = ktime_to_timeval(etime);
829 /* Subtract time delta from raw timestamp to get final
830 * vblank_time timestamp for end of vblank.
832 etime = ktime_sub_ns(etime, delta_ns);
833 *vblank_time = ktime_to_timeval(etime);
835 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
836 pipe, vbl_status, hpos, vpos,
837 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
838 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
839 duration_ns/1000, i);
843 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
845 static struct timeval get_drm_timestamp(void)
849 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
850 return ktime_to_timeval(now);
854 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
857 * @pipe: index of CRTC whose vblank timestamp to retrieve
858 * @tvblank: Pointer to target struct timeval which should receive the timestamp
859 * @flags: Flags to pass to driver:
861 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
863 * Fetches the system timestamp corresponding to the time of the most recent
864 * vblank interval on specified CRTC. May call into kms-driver to
865 * compute the timestamp with a high-precision GPU specific method.
867 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
868 * call, i.e., it isn't very precisely locked to the true vblank.
871 * True if timestamp is considered to be very precise, false otherwise.
874 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
875 struct timeval *tvblank, unsigned flags)
879 /* Define requested maximum error on timestamps (nanoseconds). */
880 int max_error = (int) drm_timestamp_precision * 1000;
882 /* Query driver if possible and precision timestamping enabled. */
883 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
884 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
890 /* GPU high precision timestamp query unsupported or failed.
891 * Return current monotonic/gettimeofday timestamp as best estimate.
893 *tvblank = get_drm_timestamp();
899 * drm_vblank_count - retrieve "cooked" vblank counter value
901 * @pipe: index of CRTC for which to retrieve the counter
903 * Fetches the "cooked" vblank count value that represents the number of
904 * vblank events since the system was booted, including lost events due to
905 * modesetting activity.
907 * This is the legacy version of drm_crtc_vblank_count().
910 * The software vblank counter.
912 u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
914 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
916 if (WARN_ON(pipe >= dev->num_crtcs))
919 return vblank->count;
921 EXPORT_SYMBOL(drm_vblank_count);
924 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
925 * @crtc: which counter to retrieve
927 * Fetches the "cooked" vblank count value that represents the number of
928 * vblank events since the system was booted, including lost events due to
929 * modesetting activity.
931 * This is the native KMS version of drm_vblank_count().
934 * The software vblank counter.
936 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
938 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
940 EXPORT_SYMBOL(drm_crtc_vblank_count);
943 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
944 * system timestamp corresponding to that vblank counter value.
946 * @pipe: index of CRTC whose counter to retrieve
947 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
949 * Fetches the "cooked" vblank count value that represents the number of
950 * vblank events since the system was booted, including lost events due to
951 * modesetting activity. Returns corresponding system timestamp of the time
952 * of the vblank interval that corresponds to the current vblank counter value.
954 * This is the legacy version of drm_crtc_vblank_count_and_time().
956 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
957 struct timeval *vblanktime)
959 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
963 if (WARN_ON(pipe >= dev->num_crtcs))
967 seq = read_seqbegin(&vblank->seqlock);
968 vblank_count = vblank->count;
969 *vblanktime = vblank->time;
970 } while (read_seqretry(&vblank->seqlock, seq));
974 EXPORT_SYMBOL(drm_vblank_count_and_time);
977 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
978 * and the system timestamp corresponding to that vblank counter value
979 * @crtc: which counter to retrieve
980 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
982 * Fetches the "cooked" vblank count value that represents the number of
983 * vblank events since the system was booted, including lost events due to
984 * modesetting activity. Returns corresponding system timestamp of the time
985 * of the vblank interval that corresponds to the current vblank counter value.
987 * This is the native KMS version of drm_vblank_count_and_time().
989 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
990 struct timeval *vblanktime)
992 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
995 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
997 static void send_vblank_event(struct drm_device *dev,
998 struct drm_pending_vblank_event *e,
999 unsigned long seq, struct timeval *now)
1001 e->event.sequence = seq;
1002 e->event.tv_sec = now->tv_sec;
1003 e->event.tv_usec = now->tv_usec;
1005 drm_send_event_locked(dev, &e->base);
1007 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
1012 * drm_arm_vblank_event - arm vblank event after pageflip
1015 * @e: the event to prepare to send
1017 * A lot of drivers need to generate vblank events for the very next vblank
1018 * interrupt. For example when the page flip interrupt happens when the page
1019 * flip gets armed, but not when it actually executes within the next vblank
1020 * period. This helper function implements exactly the required vblank arming
1023 * Caller must hold event lock. Caller must also hold a vblank reference for
1024 * the event @e, which will be dropped when the next vblank arrives.
1026 * This is the legacy version of drm_crtc_arm_vblank_event().
1028 void drm_arm_vblank_event(struct drm_device *dev, unsigned int pipe,
1029 struct drm_pending_vblank_event *e)
1031 assert_spin_locked(&dev->event_lock);
1034 e->event.sequence = drm_vblank_count(dev, pipe);
1035 list_add_tail(&e->base.link, &dev->vblank_event_list);
1037 EXPORT_SYMBOL(drm_arm_vblank_event);
1040 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1041 * @crtc: the source CRTC of the vblank event
1042 * @e: the event to send
1044 * A lot of drivers need to generate vblank events for the very next vblank
1045 * interrupt. For example when the page flip interrupt happens when the page
1046 * flip gets armed, but not when it actually executes within the next vblank
1047 * period. This helper function implements exactly the required vblank arming
1050 * Caller must hold event lock. Caller must also hold a vblank reference for
1051 * the event @e, which will be dropped when the next vblank arrives.
1053 * This is the native KMS version of drm_arm_vblank_event().
1055 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
1056 struct drm_pending_vblank_event *e)
1058 drm_arm_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1060 EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
1063 * drm_send_vblank_event - helper to send vblank event after pageflip
1066 * @e: the event to send
1068 * Updates sequence # and timestamp on event, and sends it to userspace.
1069 * Caller must hold event lock.
1071 * This is the legacy version of drm_crtc_send_vblank_event().
1073 void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
1074 struct drm_pending_vblank_event *e)
1079 if (dev->num_crtcs > 0) {
1080 seq = drm_vblank_count_and_time(dev, pipe, &now);
1084 now = get_drm_timestamp();
1087 send_vblank_event(dev, e, seq, &now);
1089 EXPORT_SYMBOL(drm_send_vblank_event);
1092 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1093 * @crtc: the source CRTC of the vblank event
1094 * @e: the event to send
1096 * Updates sequence # and timestamp on event, and sends it to userspace.
1097 * Caller must hold event lock.
1099 * This is the native KMS version of drm_send_vblank_event().
1101 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1102 struct drm_pending_vblank_event *e)
1104 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1106 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1109 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1114 * Zero on success or a negative error code on failure.
1116 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1118 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1121 assert_spin_locked(&dev->vbl_lock);
1123 spin_lock(&dev->vblank_time_lock);
1125 if (!vblank->enabled) {
1127 * Enable vblank irqs under vblank_time_lock protection.
1128 * All vblank count & timestamp updates are held off
1129 * until we are done reinitializing master counter and
1130 * timestamps. Filtercode in drm_handle_vblank() will
1131 * prevent double-accounting of same vblank interval.
1133 ret = dev->driver->enable_vblank(dev, pipe);
1134 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1136 atomic_dec(&vblank->refcount);
1138 vblank->enabled = true;
1139 drm_update_vblank_count(dev, pipe, 0);
1143 spin_unlock(&dev->vblank_time_lock);
1149 * drm_vblank_get - get a reference count on vblank events
1151 * @pipe: index of CRTC to own
1153 * Acquire a reference count on vblank events to avoid having them disabled
1156 * This is the legacy version of drm_crtc_vblank_get().
1159 * Zero on success or a negative error code on failure.
1161 int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1163 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1164 unsigned long irqflags;
1167 if (!dev->num_crtcs)
1170 if (WARN_ON(pipe >= dev->num_crtcs))
1173 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1174 /* Going from 0->1 means we have to enable interrupts again */
1175 if (atomic_add_return(1, &vblank->refcount) == 1) {
1176 ret = drm_vblank_enable(dev, pipe);
1178 if (!vblank->enabled) {
1179 atomic_dec(&vblank->refcount);
1183 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1187 EXPORT_SYMBOL(drm_vblank_get);
1190 * drm_crtc_vblank_get - get a reference count on vblank events
1191 * @crtc: which CRTC to own
1193 * Acquire a reference count on vblank events to avoid having them disabled
1196 * This is the native kms version of drm_vblank_get().
1199 * Zero on success or a negative error code on failure.
1201 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1203 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1205 EXPORT_SYMBOL(drm_crtc_vblank_get);
1208 * drm_vblank_put - release ownership of vblank events
1210 * @pipe: index of CRTC to release
1212 * Release ownership of a given vblank counter, turning off interrupts
1213 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1215 * This is the legacy version of drm_crtc_vblank_put().
1217 void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1219 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1221 if (WARN_ON(pipe >= dev->num_crtcs))
1224 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1227 /* Last user schedules interrupt disable */
1228 if (atomic_dec_and_test(&vblank->refcount)) {
1229 if (drm_vblank_offdelay == 0)
1231 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1232 vblank_disable_fn((unsigned long)vblank);
1234 mod_timer(&vblank->disable_timer,
1235 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1238 EXPORT_SYMBOL(drm_vblank_put);
1241 * drm_crtc_vblank_put - give up ownership of vblank events
1242 * @crtc: which counter to give up
1244 * Release ownership of a given vblank counter, turning off interrupts
1245 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1247 * This is the native kms version of drm_vblank_put().
1249 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1251 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1253 EXPORT_SYMBOL(drm_crtc_vblank_put);
1256 * drm_wait_one_vblank - wait for one vblank
1260 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1261 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1262 * due to lack of driver support or because the crtc is off.
1264 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1266 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1270 if (WARN_ON(pipe >= dev->num_crtcs))
1273 ret = drm_vblank_get(dev, pipe);
1274 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1277 last = drm_vblank_count(dev, pipe);
1279 ret = wait_event_timeout(vblank->queue,
1280 last != drm_vblank_count(dev, pipe),
1281 msecs_to_jiffies(100));
1283 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1285 drm_vblank_put(dev, pipe);
1287 EXPORT_SYMBOL(drm_wait_one_vblank);
1290 * drm_crtc_wait_one_vblank - wait for one vblank
1293 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1294 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1295 * due to lack of driver support or because the crtc is off.
1297 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1299 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1301 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1304 * drm_vblank_off - disable vblank events on a CRTC
1308 * Drivers can use this function to shut down the vblank interrupt handling when
1309 * disabling a crtc. This function ensures that the latest vblank frame count is
1310 * stored so that drm_vblank_on() can restore it again.
1312 * Drivers must use this function when the hardware vblank counter can get
1313 * reset, e.g. when suspending.
1315 * This is the legacy version of drm_crtc_vblank_off().
1317 void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
1319 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1320 struct drm_pending_vblank_event *e, *t;
1322 unsigned long irqflags;
1325 if (WARN_ON(pipe >= dev->num_crtcs))
1328 spin_lock_irqsave(&dev->event_lock, irqflags);
1330 spin_lock(&dev->vbl_lock);
1331 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1332 pipe, vblank->enabled, vblank->inmodeset);
1334 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1335 if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
1336 vblank_disable_and_save(dev, pipe);
1338 wake_up(&vblank->queue);
1341 * Prevent subsequent drm_vblank_get() from re-enabling
1342 * the vblank interrupt by bumping the refcount.
1344 if (!vblank->inmodeset) {
1345 atomic_inc(&vblank->refcount);
1346 vblank->inmodeset = 1;
1348 spin_unlock(&dev->vbl_lock);
1350 /* Send any queued vblank events, lest the natives grow disquiet */
1351 seq = drm_vblank_count_and_time(dev, pipe, &now);
1353 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1354 if (e->pipe != pipe)
1356 DRM_DEBUG("Sending premature vblank event on disable: "
1357 "wanted %d, current %d\n",
1358 e->event.sequence, seq);
1359 list_del(&e->base.link);
1360 drm_vblank_put(dev, pipe);
1361 send_vblank_event(dev, e, seq, &now);
1363 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1365 EXPORT_SYMBOL(drm_vblank_off);
1368 * drm_crtc_vblank_off - disable vblank events on a CRTC
1369 * @crtc: CRTC in question
1371 * Drivers can use this function to shut down the vblank interrupt handling when
1372 * disabling a crtc. This function ensures that the latest vblank frame count is
1373 * stored so that drm_vblank_on can restore it again.
1375 * Drivers must use this function when the hardware vblank counter can get
1376 * reset, e.g. when suspending.
1378 * This is the native kms version of drm_vblank_off().
1380 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1382 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1384 EXPORT_SYMBOL(drm_crtc_vblank_off);
1387 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1388 * @crtc: CRTC in question
1390 * Drivers can use this function to reset the vblank state to off at load time.
1391 * Drivers should use this together with the drm_crtc_vblank_off() and
1392 * drm_crtc_vblank_on() functions. The difference compared to
1393 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1394 * and hence doesn't need to call any driver hooks.
1396 void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1398 struct drm_device *dev = crtc->dev;
1399 unsigned long irqflags;
1400 unsigned int pipe = drm_crtc_index(crtc);
1401 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1403 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1405 * Prevent subsequent drm_vblank_get() from enabling the vblank
1406 * interrupt by bumping the refcount.
1408 if (!vblank->inmodeset) {
1409 atomic_inc(&vblank->refcount);
1410 vblank->inmodeset = 1;
1412 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1414 WARN_ON(!list_empty(&dev->vblank_event_list));
1416 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1419 * drm_vblank_on - enable vblank events on a CRTC
1423 * This functions restores the vblank interrupt state captured with
1424 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1425 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1426 * in driver load code to reflect the current hardware state of the crtc.
1428 * This is the legacy version of drm_crtc_vblank_on().
1430 void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
1432 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1433 unsigned long irqflags;
1435 if (WARN_ON(pipe >= dev->num_crtcs))
1438 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1439 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1440 pipe, vblank->enabled, vblank->inmodeset);
1442 /* Drop our private "prevent drm_vblank_get" refcount */
1443 if (vblank->inmodeset) {
1444 atomic_dec(&vblank->refcount);
1445 vblank->inmodeset = 0;
1448 drm_reset_vblank_timestamp(dev, pipe);
1451 * re-enable interrupts if there are users left, or the
1452 * user wishes vblank interrupts to be enabled all the time.
1454 if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0)
1455 WARN_ON(drm_vblank_enable(dev, pipe));
1456 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1458 EXPORT_SYMBOL(drm_vblank_on);
1461 * drm_crtc_vblank_on - enable vblank events on a CRTC
1462 * @crtc: CRTC in question
1464 * This functions restores the vblank interrupt state captured with
1465 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1466 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1467 * in driver load code to reflect the current hardware state of the crtc.
1469 * This is the native kms version of drm_vblank_on().
1471 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1473 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1475 EXPORT_SYMBOL(drm_crtc_vblank_on);
1478 * drm_vblank_pre_modeset - account for vblanks across mode sets
1482 * Account for vblank events across mode setting events, which will likely
1483 * reset the hardware frame counter.
1485 * This is done by grabbing a temporary vblank reference to ensure that the
1486 * vblank interrupt keeps running across the modeset sequence. With this the
1487 * software-side vblank frame counting will ensure that there are no jumps or
1490 * Unfortunately this approach is racy and also doesn't work when the vblank
1491 * interrupt stops running, e.g. across system suspend resume. It is therefore
1492 * highly recommended that drivers use the newer drm_vblank_off() and
1493 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1494 * using "cooked" software vblank frame counters and not relying on any hardware
1497 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1500 void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
1502 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1504 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1505 if (!dev->num_crtcs)
1508 if (WARN_ON(pipe >= dev->num_crtcs))
1512 * To avoid all the problems that might happen if interrupts
1513 * were enabled/disabled around or between these calls, we just
1514 * have the kernel take a reference on the CRTC (just once though
1515 * to avoid corrupting the count if multiple, mismatch calls occur),
1516 * so that interrupts remain enabled in the interim.
1518 if (!vblank->inmodeset) {
1519 vblank->inmodeset = 0x1;
1520 if (drm_vblank_get(dev, pipe) == 0)
1521 vblank->inmodeset |= 0x2;
1524 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1527 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1531 * This function again drops the temporary vblank reference acquired in
1532 * drm_vblank_pre_modeset.
1534 void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
1536 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1537 unsigned long irqflags;
1539 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1540 if (!dev->num_crtcs)
1543 if (WARN_ON(pipe >= dev->num_crtcs))
1546 if (vblank->inmodeset) {
1547 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1548 drm_reset_vblank_timestamp(dev, pipe);
1549 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1551 if (vblank->inmodeset & 0x2)
1552 drm_vblank_put(dev, pipe);
1554 vblank->inmodeset = 0;
1557 EXPORT_SYMBOL(drm_vblank_post_modeset);
1560 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1561 * @DRM_IOCTL_ARGS: standard ioctl arguments
1563 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1564 * ioctls around modesetting so that any lost vblank events are accounted for.
1566 * Generally the counter will reset across mode sets. If interrupts are
1567 * enabled around this call, we don't have to do anything since the counter
1568 * will have already been incremented.
1570 int drm_modeset_ctl(struct drm_device *dev, void *data,
1571 struct drm_file *file_priv)
1573 struct drm_modeset_ctl *modeset = data;
1576 /* If drm_vblank_init() hasn't been called yet, just no-op */
1577 if (!dev->num_crtcs)
1580 /* KMS drivers handle this internally */
1581 if (drm_core_check_feature(dev, DRIVER_MODESET))
1584 pipe = modeset->crtc;
1585 if (pipe >= dev->num_crtcs)
1588 switch (modeset->cmd) {
1589 case _DRM_PRE_MODESET:
1590 drm_vblank_pre_modeset(dev, pipe);
1592 case _DRM_POST_MODESET:
1593 drm_vblank_post_modeset(dev, pipe);
1602 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1603 union drm_wait_vblank *vblwait,
1604 struct drm_file *file_priv)
1606 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1607 struct drm_pending_vblank_event *e;
1609 unsigned long flags;
1613 e = kzalloc(sizeof(*e), GFP_KERNEL);
1620 e->base.pid = current->pid;
1621 e->event.base.type = DRM_EVENT_VBLANK;
1622 e->event.base.length = sizeof(e->event);
1623 e->event.user_data = vblwait->request.signal;
1625 spin_lock_irqsave(&dev->event_lock, flags);
1628 * drm_vblank_off() might have been called after we called
1629 * drm_vblank_get(). drm_vblank_off() holds event_lock
1630 * around the vblank disable, so no need for further locking.
1631 * The reference from drm_vblank_get() protects against
1632 * vblank disable from another source.
1634 if (!vblank->enabled) {
1639 ret = drm_event_reserve_init_locked(dev, file_priv, &e->base,
1645 seq = drm_vblank_count_and_time(dev, pipe, &now);
1647 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1648 (seq - vblwait->request.sequence) <= (1 << 23)) {
1649 vblwait->request.sequence = seq + 1;
1650 vblwait->reply.sequence = vblwait->request.sequence;
1653 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1654 vblwait->request.sequence, seq, pipe);
1656 trace_drm_vblank_event_queued(current->pid, pipe,
1657 vblwait->request.sequence);
1659 e->event.sequence = vblwait->request.sequence;
1660 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1661 drm_vblank_put(dev, pipe);
1662 send_vblank_event(dev, e, seq, &now);
1663 vblwait->reply.sequence = seq;
1665 /* drm_handle_vblank_events will call drm_vblank_put */
1666 list_add_tail(&e->base.link, &dev->vblank_event_list);
1667 vblwait->reply.sequence = vblwait->request.sequence;
1670 spin_unlock_irqrestore(&dev->event_lock, flags);
1675 spin_unlock_irqrestore(&dev->event_lock, flags);
1678 drm_vblank_put(dev, pipe);
1685 * \param inode device inode.
1686 * \param file_priv DRM file private.
1687 * \param cmd command.
1688 * \param data user argument, pointing to a drm_wait_vblank structure.
1689 * \return zero on success or a negative number on failure.
1691 * This function enables the vblank interrupt on the pipe requested, then
1692 * sleeps waiting for the requested sequence number to occur, and drops
1693 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1694 * after a timeout with no further vblank waits scheduled).
1696 int drm_wait_vblank(struct drm_device *dev, void *data,
1697 struct drm_file *file_priv)
1699 struct drm_vblank_crtc *vblank;
1700 union drm_wait_vblank *vblwait = data;
1702 unsigned int flags, seq, pipe, high_pipe;
1704 if (!dev->irq_enabled)
1707 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1710 if (vblwait->request.type &
1711 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1712 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1713 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1714 vblwait->request.type,
1715 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1716 _DRM_VBLANK_HIGH_CRTC_MASK));
1720 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1721 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1723 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1725 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1726 if (pipe >= dev->num_crtcs)
1729 vblank = &dev->vblank[pipe];
1731 ret = drm_vblank_get(dev, pipe);
1733 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1736 seq = drm_vblank_count(dev, pipe);
1738 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1739 case _DRM_VBLANK_RELATIVE:
1740 vblwait->request.sequence += seq;
1741 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1742 case _DRM_VBLANK_ABSOLUTE:
1749 if (flags & _DRM_VBLANK_EVENT) {
1750 /* must hold on to the vblank ref until the event fires
1751 * drm_vblank_put will be called asynchronously
1753 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1756 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1757 (seq - vblwait->request.sequence) <= (1<<23)) {
1758 vblwait->request.sequence = seq + 1;
1761 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1762 vblwait->request.sequence, pipe);
1763 vblank->last_wait = vblwait->request.sequence;
1764 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1765 (((drm_vblank_count(dev, pipe) -
1766 vblwait->request.sequence) <= (1 << 23)) ||
1768 !dev->irq_enabled));
1770 if (ret != -EINTR) {
1773 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1774 vblwait->reply.tval_sec = now.tv_sec;
1775 vblwait->reply.tval_usec = now.tv_usec;
1777 DRM_DEBUG("returning %d to client\n",
1778 vblwait->reply.sequence);
1780 DRM_DEBUG("vblank wait interrupted by signal\n");
1784 drm_vblank_put(dev, pipe);
1788 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1790 struct drm_pending_vblank_event *e, *t;
1794 assert_spin_locked(&dev->event_lock);
1796 seq = drm_vblank_count_and_time(dev, pipe, &now);
1798 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1799 if (e->pipe != pipe)
1801 if ((seq - e->event.sequence) > (1<<23))
1804 DRM_DEBUG("vblank event on %d, current %d\n",
1805 e->event.sequence, seq);
1807 list_del(&e->base.link);
1808 drm_vblank_put(dev, pipe);
1809 send_vblank_event(dev, e, seq, &now);
1812 trace_drm_vblank_event(pipe, seq);
1816 * drm_handle_vblank - handle a vblank event
1818 * @pipe: index of CRTC where this event occurred
1820 * Drivers should call this routine in their vblank interrupt handlers to
1821 * update the vblank counter and send any signals that may be pending.
1823 * This is the legacy version of drm_crtc_handle_vblank().
1825 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1827 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1828 unsigned long irqflags;
1830 if (WARN_ON_ONCE(!dev->num_crtcs))
1833 if (WARN_ON(pipe >= dev->num_crtcs))
1836 spin_lock_irqsave(&dev->event_lock, irqflags);
1838 /* Need timestamp lock to prevent concurrent execution with
1839 * vblank enable/disable, as this would cause inconsistent
1840 * or corrupted timestamps and vblank counts.
1842 spin_lock(&dev->vblank_time_lock);
1844 /* Vblank irq handling disabled. Nothing to do. */
1845 if (!vblank->enabled) {
1846 spin_unlock(&dev->vblank_time_lock);
1847 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1851 drm_update_vblank_count(dev, pipe, DRM_CALLED_FROM_VBLIRQ);
1853 spin_unlock(&dev->vblank_time_lock);
1855 wake_up(&vblank->queue);
1856 drm_handle_vblank_events(dev, pipe);
1858 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1862 EXPORT_SYMBOL(drm_handle_vblank);
1865 * drm_crtc_handle_vblank - handle a vblank event
1866 * @crtc: where this event occurred
1868 * Drivers should call this routine in their vblank interrupt handlers to
1869 * update the vblank counter and send any signals that may be pending.
1871 * This is the native KMS version of drm_handle_vblank().
1874 * True if the event was successfully handled, false on failure.
1876 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1878 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1880 EXPORT_SYMBOL(drm_crtc_handle_vblank);
1883 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1885 * @pipe: CRTC for which to read the counter
1887 * Drivers can plug this into the .get_vblank_counter() function if
1888 * there is no useable hardware frame counter available.
1893 u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
1897 EXPORT_SYMBOL(drm_vblank_no_hw_counter);