2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, pipe, count) \
47 ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
61 struct timeval *tvblank, unsigned flags);
63 static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */
66 * Default to use monotonic timestamps for wait-for-vblank and page-flip
69 unsigned int drm_timestamp_monotonic = 1;
71 static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */
73 module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600);
74 module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600);
75 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
76 MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
77 MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]");
78 MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps");
80 static void store_vblank(struct drm_device *dev, unsigned int pipe,
82 struct timeval *t_vblank, u32 last)
84 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
87 assert_spin_locked(&dev->vblank_time_lock);
91 /* All writers hold the spinlock, but readers are serialized by
92 * the latching of vblank->count below.
94 tslot = vblank->count + vblank_count_inc;
95 vblanktimestamp(dev, pipe, tslot) = *t_vblank;
98 * vblank timestamp updates are protected on the write side with
99 * vblank_time_lock, but on the read side done locklessly using a
100 * sequence-lock on the vblank counter. Ensure correct ordering using
101 * memory barrriers. We need the barrier both before and also after the
102 * counter update to synchronize with the next timestamp write.
103 * The read-side barriers for this are in drm_vblank_count_and_time.
106 vblank->count += vblank_count_inc;
111 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
113 * @pipe: index of CRTC for which to reset the timestamp
115 * Reset the stored timestamp for the current vblank count to correspond
116 * to the last vblank occurred.
118 * Only to be called from drm_vblank_on().
120 * Note: caller must hold dev->vbl_lock since this reads & writes
121 * device vblank fields.
123 static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe)
127 struct timeval t_vblank;
128 int count = DRM_TIMESTAMP_MAXRETRIES;
130 spin_lock(&dev->vblank_time_lock);
133 * sample the current counter to avoid random jumps
134 * when drm_vblank_enable() applies the diff
137 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
138 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
139 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
142 * Only reinitialize corresponding vblank timestamp if high-precision query
143 * available and didn't fail. Otherwise reinitialize delayed at next vblank
144 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
147 t_vblank = (struct timeval) {0, 0};
150 * +1 to make sure user will never see the same
151 * vblank counter value before and after a modeset
153 store_vblank(dev, pipe, 1, &t_vblank, cur_vblank);
155 spin_unlock(&dev->vblank_time_lock);
159 * drm_update_vblank_count - update the master vblank counter
161 * @pipe: counter to update
163 * Call back into the driver to update the appropriate vblank counter
164 * (specified by @pipe). Deal with wraparound, if it occurred, and
165 * update the last read value so we can deal with wraparound on the next
168 * Only necessary when going from off->on, to account for frames we
169 * didn't get an interrupt for.
171 * Note: caller must hold dev->vbl_lock since this reads & writes
172 * device vblank fields.
174 static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
177 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
178 u32 cur_vblank, diff;
180 struct timeval t_vblank;
181 int count = DRM_TIMESTAMP_MAXRETRIES;
182 int framedur_ns = vblank->framedur_ns;
185 * Interrupts were disabled prior to this call, so deal with counter
187 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
188 * here if the register is small or we had vblank interrupts off for
191 * We repeat the hardware vblank counter & timestamp query until
192 * we get consistent results. This to prevent races between gpu
193 * updating its hardware counter while we are retrieving the
194 * corresponding vblank timestamp.
197 cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
198 rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
199 } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
201 if (dev->max_vblank_count != 0) {
202 /* trust the hw counter when it's around */
203 diff = (cur_vblank - vblank->last) & dev->max_vblank_count;
204 } else if (rc && framedur_ns) {
205 const struct timeval *t_old;
208 t_old = &vblanktimestamp(dev, pipe, vblank->count);
209 diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old);
212 * Figure out how many vblanks we've missed based
213 * on the difference in the timestamps and the
214 * frame/field duration.
216 diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns);
218 if (diff == 0 && flags & DRM_CALLED_FROM_VBLIRQ)
219 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
220 " diff_ns = %lld, framedur_ns = %d)\n",
221 pipe, (long long) diff_ns, framedur_ns);
223 /* some kind of default for drivers w/o accurate vbl timestamping */
224 diff = (flags & DRM_CALLED_FROM_VBLIRQ) != 0;
227 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
228 " current=%u, diff=%u, hw=%u hw_last=%u\n",
229 pipe, vblank->count, diff, cur_vblank, vblank->last);
232 WARN_ON_ONCE(cur_vblank != vblank->last);
237 * Only reinitialize corresponding vblank timestamp if high-precision query
238 * available and didn't fail, or we were called from the vblank interrupt.
239 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
240 * for now, to mark the vblanktimestamp as invalid.
242 if (!rc && (flags & DRM_CALLED_FROM_VBLIRQ) == 0)
243 t_vblank = (struct timeval) {0, 0};
245 store_vblank(dev, pipe, diff, &t_vblank, cur_vblank);
249 * Disable vblank irq's on crtc, make sure that last vblank count
250 * of hardware and corresponding consistent software vblank counter
251 * are preserved, even if there are any spurious vblank irq's after
254 static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
256 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
257 unsigned long irqflags;
259 /* Prevent vblank irq processing while disabling vblank irqs,
260 * so no updates of timestamps or count can happen after we've
261 * disabled. Needed to prevent races in case of delayed irq's.
263 spin_lock_irqsave(&dev->vblank_time_lock, irqflags);
266 * Only disable vblank interrupts if they're enabled. This avoids
267 * calling the ->disable_vblank() operation in atomic context with the
268 * hardware potentially runtime suspended.
270 if (vblank->enabled) {
271 dev->driver->disable_vblank(dev, pipe);
272 vblank->enabled = false;
276 * Always update the count and timestamp to maintain the
277 * appearance that the counter has been ticking all along until
278 * this time. This makes the count account for the entire time
279 * between drm_vblank_on() and drm_vblank_off().
281 drm_update_vblank_count(dev, pipe, 0);
283 spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
286 static void vblank_disable_fn(unsigned long arg)
288 struct drm_vblank_crtc *vblank = (void *)arg;
289 struct drm_device *dev = vblank->dev;
290 unsigned int pipe = vblank->pipe;
291 unsigned long irqflags;
293 if (!dev->vblank_disable_allowed)
296 spin_lock_irqsave(&dev->vbl_lock, irqflags);
297 if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
298 DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
299 vblank_disable_and_save(dev, pipe);
301 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
305 * drm_vblank_cleanup - cleanup vblank support
308 * This function cleans up any resources allocated in drm_vblank_init.
310 void drm_vblank_cleanup(struct drm_device *dev)
314 /* Bail if the driver didn't call drm_vblank_init() */
315 if (dev->num_crtcs == 0)
318 for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
319 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
321 WARN_ON(vblank->enabled &&
322 drm_core_check_feature(dev, DRIVER_MODESET));
324 del_timer_sync(&vblank->disable_timer);
331 EXPORT_SYMBOL(drm_vblank_cleanup);
334 * drm_vblank_init - initialize vblank support
336 * @num_crtcs: number of CRTCs supported by @dev
338 * This function initializes vblank support for @num_crtcs display pipelines.
341 * Zero on success or a negative error code on failure.
343 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
348 spin_lock_init(&dev->vbl_lock);
349 spin_lock_init(&dev->vblank_time_lock);
351 dev->num_crtcs = num_crtcs;
353 dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
357 for (i = 0; i < num_crtcs; i++) {
358 struct drm_vblank_crtc *vblank = &dev->vblank[i];
362 init_waitqueue_head(&vblank->queue);
363 setup_timer(&vblank->disable_timer, vblank_disable_fn,
364 (unsigned long)vblank);
367 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
369 /* Driver specific high-precision vblank timestamping supported? */
370 if (dev->driver->get_vblank_timestamp)
371 DRM_INFO("Driver supports precise vblank timestamp query.\n");
373 DRM_INFO("No driver support for vblank timestamp query.\n");
375 /* Must have precise timestamping for reliable vblank instant disable */
376 if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) {
377 dev->vblank_disable_immediate = false;
378 DRM_INFO("Setting vblank_disable_immediate to false because "
379 "get_vblank_timestamp == NULL\n");
382 dev->vblank_disable_allowed = false;
390 EXPORT_SYMBOL(drm_vblank_init);
392 static void drm_irq_vgaarb_nokms(void *cookie, bool state)
394 struct drm_device *dev = cookie;
396 if (dev->driver->vgaarb_irq) {
397 dev->driver->vgaarb_irq(dev, state);
401 if (!dev->irq_enabled)
405 if (dev->driver->irq_uninstall)
406 dev->driver->irq_uninstall(dev);
408 if (dev->driver->irq_preinstall)
409 dev->driver->irq_preinstall(dev);
410 if (dev->driver->irq_postinstall)
411 dev->driver->irq_postinstall(dev);
416 * drm_irq_install - install IRQ handler
418 * @irq: IRQ number to install the handler for
420 * Initializes the IRQ related data. Installs the handler, calling the driver
421 * irq_preinstall() and irq_postinstall() functions before and after the
424 * This is the simplified helper interface provided for drivers with no special
425 * needs. Drivers which need to install interrupt handlers for multiple
426 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
427 * that vblank interrupts are available.
430 * Zero on success or a negative error code on failure.
432 int drm_irq_install(struct drm_device *dev, int irq)
435 unsigned long sh_flags = 0;
437 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
443 /* Driver must have been initialized */
444 if (!dev->dev_private)
447 if (dev->irq_enabled)
449 dev->irq_enabled = true;
451 DRM_DEBUG("irq=%d\n", irq);
453 /* Before installing handler */
454 if (dev->driver->irq_preinstall)
455 dev->driver->irq_preinstall(dev);
457 /* Install handler */
458 if (drm_core_check_feature(dev, DRIVER_IRQ_SHARED))
459 sh_flags = IRQF_SHARED;
461 ret = request_irq(irq, dev->driver->irq_handler,
462 sh_flags, dev->driver->name, dev);
465 dev->irq_enabled = false;
469 if (!drm_core_check_feature(dev, DRIVER_MODESET))
470 vga_client_register(dev->pdev, (void *)dev, drm_irq_vgaarb_nokms, NULL);
472 /* After installing handler */
473 if (dev->driver->irq_postinstall)
474 ret = dev->driver->irq_postinstall(dev);
477 dev->irq_enabled = false;
478 if (!drm_core_check_feature(dev, DRIVER_MODESET))
479 vga_client_register(dev->pdev, NULL, NULL, NULL);
487 EXPORT_SYMBOL(drm_irq_install);
490 * drm_irq_uninstall - uninstall the IRQ handler
493 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
494 * This should only be called by drivers which used drm_irq_install() to set up
495 * their interrupt handler. Other drivers must only reset
496 * drm_device->irq_enabled to false.
498 * Note that for kernel modesetting drivers it is a bug if this function fails.
499 * The sanity checks are only to catch buggy user modesetting drivers which call
500 * the same function through an ioctl.
503 * Zero on success or a negative error code on failure.
505 int drm_irq_uninstall(struct drm_device *dev)
507 unsigned long irqflags;
511 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
514 irq_enabled = dev->irq_enabled;
515 dev->irq_enabled = false;
518 * Wake up any waiters so they don't hang. This is just to paper over
519 * isssues for UMS drivers which aren't in full control of their
520 * vblank/irq handling. KMS drivers must ensure that vblanks are all
521 * disabled when uninstalling the irq handler.
523 if (dev->num_crtcs) {
524 spin_lock_irqsave(&dev->vbl_lock, irqflags);
525 for (i = 0; i < dev->num_crtcs; i++) {
526 struct drm_vblank_crtc *vblank = &dev->vblank[i];
528 if (!vblank->enabled)
531 WARN_ON(drm_core_check_feature(dev, DRIVER_MODESET));
533 vblank_disable_and_save(dev, i);
534 wake_up(&vblank->queue);
536 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
542 DRM_DEBUG("irq=%d\n", dev->irq);
544 if (!drm_core_check_feature(dev, DRIVER_MODESET))
545 vga_client_register(dev->pdev, NULL, NULL, NULL);
547 if (dev->driver->irq_uninstall)
548 dev->driver->irq_uninstall(dev);
550 free_irq(dev->irq, dev);
554 EXPORT_SYMBOL(drm_irq_uninstall);
559 * \param inode device inode.
560 * \param file_priv DRM file private.
561 * \param cmd command.
562 * \param arg user argument, pointing to a drm_control structure.
563 * \return zero on success or a negative number on failure.
565 * Calls irq_install() or irq_uninstall() according to \p arg.
567 int drm_control(struct drm_device *dev, void *data,
568 struct drm_file *file_priv)
570 struct drm_control *ctl = data;
573 /* if we haven't irq we fallback for compatibility reasons -
574 * this used to be a separate function in drm_dma.h
577 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ))
579 if (drm_core_check_feature(dev, DRIVER_MODESET))
581 /* UMS was only ever support on pci devices. */
582 if (WARN_ON(!dev->pdev))
586 case DRM_INST_HANDLER:
587 irq = dev->pdev->irq;
589 if (dev->if_version < DRM_IF_VERSION(1, 2) &&
592 mutex_lock(&dev->struct_mutex);
593 ret = drm_irq_install(dev, irq);
594 mutex_unlock(&dev->struct_mutex);
597 case DRM_UNINST_HANDLER:
598 mutex_lock(&dev->struct_mutex);
599 ret = drm_irq_uninstall(dev);
600 mutex_unlock(&dev->struct_mutex);
609 * drm_calc_timestamping_constants - calculate vblank timestamp constants
610 * @crtc: drm_crtc whose timestamp constants should be updated.
611 * @mode: display mode containing the scanout timings
613 * Calculate and store various constants which are later
614 * needed by vblank and swap-completion timestamping, e.g,
615 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
616 * derived from CRTC's true scanout timing, so they take
617 * things like panel scaling or other adjustments into account.
619 void drm_calc_timestamping_constants(struct drm_crtc *crtc,
620 const struct drm_display_mode *mode)
622 struct drm_device *dev = crtc->dev;
623 unsigned int pipe = drm_crtc_index(crtc);
624 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
625 int linedur_ns = 0, framedur_ns = 0;
626 int dotclock = mode->crtc_clock;
631 if (WARN_ON(pipe >= dev->num_crtcs))
634 /* Valid dotclock? */
636 int frame_size = mode->crtc_htotal * mode->crtc_vtotal;
639 * Convert scanline length in pixels and video
640 * dot clock to line duration and frame duration
643 linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock);
644 framedur_ns = div_u64((u64) frame_size * 1000000, dotclock);
647 * Fields of interlaced scanout modes are only half a frame duration.
649 if (mode->flags & DRM_MODE_FLAG_INTERLACE)
652 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
655 vblank->linedur_ns = linedur_ns;
656 vblank->framedur_ns = framedur_ns;
658 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
659 crtc->base.id, mode->crtc_htotal,
660 mode->crtc_vtotal, mode->crtc_vdisplay);
661 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
662 crtc->base.id, dotclock, framedur_ns, linedur_ns);
664 EXPORT_SYMBOL(drm_calc_timestamping_constants);
667 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
669 * @pipe: index of CRTC whose vblank timestamp to retrieve
670 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
671 * On return contains true maximum error of timestamp
672 * @vblank_time: Pointer to struct timeval which should receive the timestamp
673 * @flags: Flags to pass to driver:
675 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
676 * @mode: mode which defines the scanout timings
678 * Implements calculation of exact vblank timestamps from given drm_display_mode
679 * timings and current video scanout position of a CRTC. This can be called from
680 * within get_vblank_timestamp() implementation of a kms driver to implement the
681 * actual timestamping.
683 * Should return timestamps conforming to the OML_sync_control OpenML
684 * extension specification. The timestamp corresponds to the end of
685 * the vblank interval, aka start of scanout of topmost-leftmost display
686 * pixel in the following video frame.
688 * Requires support for optional dev->driver->get_scanout_position()
689 * in kms driver, plus a bit of setup code to provide a drm_display_mode
690 * that corresponds to the true scanout timing.
692 * The current implementation only handles standard video modes. It
693 * returns as no operation if a doublescan or interlaced video mode is
694 * active. Higher level code is expected to handle this.
697 * Negative value on error, failure or if not supported in current
700 * -EINVAL - Invalid CRTC.
701 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
702 * -ENOTSUPP - Function not supported in current display mode.
703 * -EIO - Failed, e.g., due to failed scanout position query.
705 * Returns or'ed positive status flags on success:
707 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
708 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
711 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
714 struct timeval *vblank_time,
716 const struct drm_display_mode *mode)
718 struct timeval tv_etime;
719 ktime_t stime, etime;
720 unsigned int vbl_status;
721 int ret = DRM_VBLANKTIME_SCANOUTPOS_METHOD;
723 int delta_ns, duration_ns;
725 if (pipe >= dev->num_crtcs) {
726 DRM_ERROR("Invalid crtc %u\n", pipe);
730 /* Scanout position query not supported? Should not happen. */
731 if (!dev->driver->get_scanout_position) {
732 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
736 /* If mode timing undefined, just return as no-op:
737 * Happens during initial modesetting of a crtc.
739 if (mode->crtc_clock == 0) {
740 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe);
744 /* Get current scanout position with system timestamp.
745 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
746 * if single query takes longer than max_error nanoseconds.
748 * This guarantees a tight bound on maximum error if
749 * code gets preempted or delayed for some reason.
751 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) {
753 * Get vertical and horizontal scanout position vpos, hpos,
754 * and bounding timestamps stime, etime, pre/post query.
756 vbl_status = dev->driver->get_scanout_position(dev, pipe, flags,
761 /* Return as no-op if scanout query unsupported or failed. */
762 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) {
763 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
768 /* Compute uncertainty in timestamp of scanout position query. */
769 duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime);
771 /* Accept result with < max_error nsecs timing uncertainty. */
772 if (duration_ns <= *max_error)
776 /* Noisy system timing? */
777 if (i == DRM_TIMESTAMP_MAXRETRIES) {
778 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
779 pipe, duration_ns/1000, *max_error/1000, i);
782 /* Return upper bound of timestamp precision error. */
783 *max_error = duration_ns;
785 /* Check if in vblank area:
786 * vpos is >=0 in video scanout area, but negative
787 * within vblank area, counting down the number of lines until
790 if (vbl_status & DRM_SCANOUTPOS_IN_VBLANK)
791 ret |= DRM_VBLANKTIME_IN_VBLANK;
793 /* Convert scanout position into elapsed time at raw_time query
794 * since start of scanout at first display scanline. delta_ns
795 * can be negative if start of scanout hasn't happened yet.
797 delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos),
800 if (!drm_timestamp_monotonic)
801 etime = ktime_mono_to_real(etime);
803 /* save this only for debugging purposes */
804 tv_etime = ktime_to_timeval(etime);
805 /* Subtract time delta from raw timestamp to get final
806 * vblank_time timestamp for end of vblank.
809 etime = ktime_add_ns(etime, -delta_ns);
811 etime = ktime_sub_ns(etime, delta_ns);
812 *vblank_time = ktime_to_timeval(etime);
814 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
815 pipe, vbl_status, hpos, vpos,
816 (long)tv_etime.tv_sec, (long)tv_etime.tv_usec,
817 (long)vblank_time->tv_sec, (long)vblank_time->tv_usec,
818 duration_ns/1000, i);
822 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos);
824 static struct timeval get_drm_timestamp(void)
828 now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real();
829 return ktime_to_timeval(now);
833 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
836 * @pipe: index of CRTC whose vblank timestamp to retrieve
837 * @tvblank: Pointer to target struct timeval which should receive the timestamp
838 * @flags: Flags to pass to driver:
840 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
842 * Fetches the system timestamp corresponding to the time of the most recent
843 * vblank interval on specified CRTC. May call into kms-driver to
844 * compute the timestamp with a high-precision GPU specific method.
846 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
847 * call, i.e., it isn't very precisely locked to the true vblank.
850 * True if timestamp is considered to be very precise, false otherwise.
853 drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe,
854 struct timeval *tvblank, unsigned flags)
858 /* Define requested maximum error on timestamps (nanoseconds). */
859 int max_error = (int) drm_timestamp_precision * 1000;
861 /* Query driver if possible and precision timestamping enabled. */
862 if (dev->driver->get_vblank_timestamp && (max_error > 0)) {
863 ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error,
869 /* GPU high precision timestamp query unsupported or failed.
870 * Return current monotonic/gettimeofday timestamp as best estimate.
872 *tvblank = get_drm_timestamp();
878 * drm_vblank_count - retrieve "cooked" vblank counter value
880 * @pipe: index of CRTC for which to retrieve the counter
882 * Fetches the "cooked" vblank count value that represents the number of
883 * vblank events since the system was booted, including lost events due to
884 * modesetting activity.
886 * This is the legacy version of drm_crtc_vblank_count().
889 * The software vblank counter.
891 u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe)
893 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
895 if (WARN_ON(pipe >= dev->num_crtcs))
898 return vblank->count;
900 EXPORT_SYMBOL(drm_vblank_count);
903 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
904 * @crtc: which counter to retrieve
906 * Fetches the "cooked" vblank count value that represents the number of
907 * vblank events since the system was booted, including lost events due to
908 * modesetting activity.
910 * This is the native KMS version of drm_vblank_count().
913 * The software vblank counter.
915 u32 drm_crtc_vblank_count(struct drm_crtc *crtc)
917 return drm_vblank_count(crtc->dev, drm_crtc_index(crtc));
919 EXPORT_SYMBOL(drm_crtc_vblank_count);
922 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
923 * system timestamp corresponding to that vblank counter value.
925 * @pipe: index of CRTC whose counter to retrieve
926 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
928 * Fetches the "cooked" vblank count value that represents the number of
929 * vblank events since the system was booted, including lost events due to
930 * modesetting activity. Returns corresponding system timestamp of the time
931 * of the vblank interval that corresponds to the current vblank counter value.
933 * This is the legacy version of drm_crtc_vblank_count_and_time().
935 u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe,
936 struct timeval *vblanktime)
938 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
939 int count = DRM_TIMESTAMP_MAXRETRIES;
942 if (WARN_ON(pipe >= dev->num_crtcs))
946 * Vblank timestamps are read lockless. To ensure consistency the vblank
947 * counter is rechecked and ordering is ensured using memory barriers.
948 * This works like a seqlock. The write-side barriers are in store_vblank.
951 cur_vblank = vblank->count;
953 *vblanktime = vblanktimestamp(dev, pipe, cur_vblank);
955 } while (cur_vblank != vblank->count && --count > 0);
959 EXPORT_SYMBOL(drm_vblank_count_and_time);
962 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
963 * and the system timestamp corresponding to that vblank counter value
964 * @crtc: which counter to retrieve
965 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
967 * Fetches the "cooked" vblank count value that represents the number of
968 * vblank events since the system was booted, including lost events due to
969 * modesetting activity. Returns corresponding system timestamp of the time
970 * of the vblank interval that corresponds to the current vblank counter value.
972 * This is the native KMS version of drm_vblank_count_and_time().
974 u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
975 struct timeval *vblanktime)
977 return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc),
980 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time);
982 static void send_vblank_event(struct drm_device *dev,
983 struct drm_pending_vblank_event *e,
984 unsigned long seq, struct timeval *now)
986 assert_spin_locked(&dev->event_lock);
988 e->event.sequence = seq;
989 e->event.tv_sec = now->tv_sec;
990 e->event.tv_usec = now->tv_usec;
992 list_add_tail(&e->base.link,
993 &e->base.file_priv->event_list);
994 wake_up_interruptible(&e->base.file_priv->event_wait);
995 trace_drm_vblank_event_delivered(e->base.pid, e->pipe,
1000 * drm_arm_vblank_event - arm vblank event after pageflip
1003 * @e: the event to prepare to send
1005 * A lot of drivers need to generate vblank events for the very next vblank
1006 * interrupt. For example when the page flip interrupt happens when the page
1007 * flip gets armed, but not when it actually executes within the next vblank
1008 * period. This helper function implements exactly the required vblank arming
1011 * Caller must hold event lock. Caller must also hold a vblank reference for
1012 * the event @e, which will be dropped when the next vblank arrives.
1014 * This is the legacy version of drm_crtc_arm_vblank_event().
1016 void drm_arm_vblank_event(struct drm_device *dev, unsigned int pipe,
1017 struct drm_pending_vblank_event *e)
1019 assert_spin_locked(&dev->event_lock);
1022 e->event.sequence = drm_vblank_count(dev, pipe);
1023 list_add_tail(&e->base.link, &dev->vblank_event_list);
1025 EXPORT_SYMBOL(drm_arm_vblank_event);
1028 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1029 * @crtc: the source CRTC of the vblank event
1030 * @e: the event to send
1032 * A lot of drivers need to generate vblank events for the very next vblank
1033 * interrupt. For example when the page flip interrupt happens when the page
1034 * flip gets armed, but not when it actually executes within the next vblank
1035 * period. This helper function implements exactly the required vblank arming
1038 * Caller must hold event lock. Caller must also hold a vblank reference for
1039 * the event @e, which will be dropped when the next vblank arrives.
1041 * This is the native KMS version of drm_arm_vblank_event().
1043 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
1044 struct drm_pending_vblank_event *e)
1046 drm_arm_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1048 EXPORT_SYMBOL(drm_crtc_arm_vblank_event);
1051 * drm_send_vblank_event - helper to send vblank event after pageflip
1054 * @e: the event to send
1056 * Updates sequence # and timestamp on event, and sends it to userspace.
1057 * Caller must hold event lock.
1059 * This is the legacy version of drm_crtc_send_vblank_event().
1061 void drm_send_vblank_event(struct drm_device *dev, unsigned int pipe,
1062 struct drm_pending_vblank_event *e)
1067 if (dev->num_crtcs > 0) {
1068 seq = drm_vblank_count_and_time(dev, pipe, &now);
1072 now = get_drm_timestamp();
1075 send_vblank_event(dev, e, seq, &now);
1077 EXPORT_SYMBOL(drm_send_vblank_event);
1080 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1081 * @crtc: the source CRTC of the vblank event
1082 * @e: the event to send
1084 * Updates sequence # and timestamp on event, and sends it to userspace.
1085 * Caller must hold event lock.
1087 * This is the native KMS version of drm_send_vblank_event().
1089 void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
1090 struct drm_pending_vblank_event *e)
1092 drm_send_vblank_event(crtc->dev, drm_crtc_index(crtc), e);
1094 EXPORT_SYMBOL(drm_crtc_send_vblank_event);
1097 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1102 * Zero on success or a negative error code on failure.
1104 static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
1106 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1109 assert_spin_locked(&dev->vbl_lock);
1111 spin_lock(&dev->vblank_time_lock);
1113 if (!vblank->enabled) {
1115 * Enable vblank irqs under vblank_time_lock protection.
1116 * All vblank count & timestamp updates are held off
1117 * until we are done reinitializing master counter and
1118 * timestamps. Filtercode in drm_handle_vblank() will
1119 * prevent double-accounting of same vblank interval.
1121 ret = dev->driver->enable_vblank(dev, pipe);
1122 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
1124 atomic_dec(&vblank->refcount);
1126 vblank->enabled = true;
1127 drm_update_vblank_count(dev, pipe, 0);
1131 spin_unlock(&dev->vblank_time_lock);
1137 * drm_vblank_get - get a reference count on vblank events
1139 * @pipe: index of CRTC to own
1141 * Acquire a reference count on vblank events to avoid having them disabled
1144 * This is the legacy version of drm_crtc_vblank_get().
1147 * Zero on success or a negative error code on failure.
1149 int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
1151 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1152 unsigned long irqflags;
1155 if (!dev->num_crtcs)
1158 if (WARN_ON(pipe >= dev->num_crtcs))
1161 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1162 /* Going from 0->1 means we have to enable interrupts again */
1163 if (atomic_add_return(1, &vblank->refcount) == 1) {
1164 ret = drm_vblank_enable(dev, pipe);
1166 if (!vblank->enabled) {
1167 atomic_dec(&vblank->refcount);
1171 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1175 EXPORT_SYMBOL(drm_vblank_get);
1178 * drm_crtc_vblank_get - get a reference count on vblank events
1179 * @crtc: which CRTC to own
1181 * Acquire a reference count on vblank events to avoid having them disabled
1184 * This is the native kms version of drm_vblank_get().
1187 * Zero on success or a negative error code on failure.
1189 int drm_crtc_vblank_get(struct drm_crtc *crtc)
1191 return drm_vblank_get(crtc->dev, drm_crtc_index(crtc));
1193 EXPORT_SYMBOL(drm_crtc_vblank_get);
1196 * drm_vblank_put - release ownership of vblank events
1198 * @pipe: index of CRTC to release
1200 * Release ownership of a given vblank counter, turning off interrupts
1201 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1203 * This is the legacy version of drm_crtc_vblank_put().
1205 void drm_vblank_put(struct drm_device *dev, unsigned int pipe)
1207 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1209 if (WARN_ON(pipe >= dev->num_crtcs))
1212 if (WARN_ON(atomic_read(&vblank->refcount) == 0))
1215 /* Last user schedules interrupt disable */
1216 if (atomic_dec_and_test(&vblank->refcount)) {
1217 if (drm_vblank_offdelay == 0)
1219 else if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0)
1220 vblank_disable_fn((unsigned long)vblank);
1222 mod_timer(&vblank->disable_timer,
1223 jiffies + ((drm_vblank_offdelay * HZ)/1000));
1226 EXPORT_SYMBOL(drm_vblank_put);
1229 * drm_crtc_vblank_put - give up ownership of vblank events
1230 * @crtc: which counter to give up
1232 * Release ownership of a given vblank counter, turning off interrupts
1233 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1235 * This is the native kms version of drm_vblank_put().
1237 void drm_crtc_vblank_put(struct drm_crtc *crtc)
1239 drm_vblank_put(crtc->dev, drm_crtc_index(crtc));
1241 EXPORT_SYMBOL(drm_crtc_vblank_put);
1244 * drm_wait_one_vblank - wait for one vblank
1248 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1249 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1250 * due to lack of driver support or because the crtc is off.
1252 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe)
1254 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1258 if (WARN_ON(pipe >= dev->num_crtcs))
1261 ret = drm_vblank_get(dev, pipe);
1262 if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret))
1265 last = drm_vblank_count(dev, pipe);
1267 ret = wait_event_timeout(vblank->queue,
1268 last != drm_vblank_count(dev, pipe),
1269 msecs_to_jiffies(100));
1271 WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe);
1273 drm_vblank_put(dev, pipe);
1275 EXPORT_SYMBOL(drm_wait_one_vblank);
1278 * drm_crtc_wait_one_vblank - wait for one vblank
1281 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1282 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1283 * due to lack of driver support or because the crtc is off.
1285 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc)
1287 drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc));
1289 EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
1292 * drm_vblank_off - disable vblank events on a CRTC
1296 * Drivers can use this function to shut down the vblank interrupt handling when
1297 * disabling a crtc. This function ensures that the latest vblank frame count is
1298 * stored so that drm_vblank_on() can restore it again.
1300 * Drivers must use this function when the hardware vblank counter can get
1301 * reset, e.g. when suspending.
1303 * This is the legacy version of drm_crtc_vblank_off().
1305 void drm_vblank_off(struct drm_device *dev, unsigned int pipe)
1307 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1308 struct drm_pending_vblank_event *e, *t;
1310 unsigned long irqflags;
1313 if (WARN_ON(pipe >= dev->num_crtcs))
1316 spin_lock_irqsave(&dev->event_lock, irqflags);
1318 spin_lock(&dev->vbl_lock);
1319 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1320 pipe, vblank->enabled, vblank->inmodeset);
1322 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1323 if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
1324 vblank_disable_and_save(dev, pipe);
1326 wake_up(&vblank->queue);
1329 * Prevent subsequent drm_vblank_get() from re-enabling
1330 * the vblank interrupt by bumping the refcount.
1332 if (!vblank->inmodeset) {
1333 atomic_inc(&vblank->refcount);
1334 vblank->inmodeset = 1;
1336 spin_unlock(&dev->vbl_lock);
1338 /* Send any queued vblank events, lest the natives grow disquiet */
1339 seq = drm_vblank_count_and_time(dev, pipe, &now);
1341 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1342 if (e->pipe != pipe)
1344 DRM_DEBUG("Sending premature vblank event on disable: "
1345 "wanted %d, current %d\n",
1346 e->event.sequence, seq);
1347 list_del(&e->base.link);
1348 drm_vblank_put(dev, pipe);
1349 send_vblank_event(dev, e, seq, &now);
1351 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1353 EXPORT_SYMBOL(drm_vblank_off);
1356 * drm_crtc_vblank_off - disable vblank events on a CRTC
1357 * @crtc: CRTC in question
1359 * Drivers can use this function to shut down the vblank interrupt handling when
1360 * disabling a crtc. This function ensures that the latest vblank frame count is
1361 * stored so that drm_vblank_on can restore it again.
1363 * Drivers must use this function when the hardware vblank counter can get
1364 * reset, e.g. when suspending.
1366 * This is the native kms version of drm_vblank_off().
1368 void drm_crtc_vblank_off(struct drm_crtc *crtc)
1370 drm_vblank_off(crtc->dev, drm_crtc_index(crtc));
1372 EXPORT_SYMBOL(drm_crtc_vblank_off);
1375 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1376 * @crtc: CRTC in question
1378 * Drivers can use this function to reset the vblank state to off at load time.
1379 * Drivers should use this together with the drm_crtc_vblank_off() and
1380 * drm_crtc_vblank_on() functions. The difference compared to
1381 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1382 * and hence doesn't need to call any driver hooks.
1384 void drm_crtc_vblank_reset(struct drm_crtc *crtc)
1386 struct drm_device *dev = crtc->dev;
1387 unsigned long irqflags;
1388 unsigned int pipe = drm_crtc_index(crtc);
1389 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1391 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1393 * Prevent subsequent drm_vblank_get() from enabling the vblank
1394 * interrupt by bumping the refcount.
1396 if (!vblank->inmodeset) {
1397 atomic_inc(&vblank->refcount);
1398 vblank->inmodeset = 1;
1400 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1402 WARN_ON(!list_empty(&dev->vblank_event_list));
1404 EXPORT_SYMBOL(drm_crtc_vblank_reset);
1407 * drm_vblank_on - enable vblank events on a CRTC
1411 * This functions restores the vblank interrupt state captured with
1412 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1413 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1414 * in driver load code to reflect the current hardware state of the crtc.
1416 * This is the legacy version of drm_crtc_vblank_on().
1418 void drm_vblank_on(struct drm_device *dev, unsigned int pipe)
1420 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1421 unsigned long irqflags;
1423 if (WARN_ON(pipe >= dev->num_crtcs))
1426 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1427 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1428 pipe, vblank->enabled, vblank->inmodeset);
1430 /* Drop our private "prevent drm_vblank_get" refcount */
1431 if (vblank->inmodeset) {
1432 atomic_dec(&vblank->refcount);
1433 vblank->inmodeset = 0;
1436 drm_reset_vblank_timestamp(dev, pipe);
1439 * re-enable interrupts if there are users left, or the
1440 * user wishes vblank interrupts to be enabled all the time.
1442 if (atomic_read(&vblank->refcount) != 0 ||
1443 (!dev->vblank_disable_immediate && drm_vblank_offdelay == 0))
1444 WARN_ON(drm_vblank_enable(dev, pipe));
1445 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1447 EXPORT_SYMBOL(drm_vblank_on);
1450 * drm_crtc_vblank_on - enable vblank events on a CRTC
1451 * @crtc: CRTC in question
1453 * This functions restores the vblank interrupt state captured with
1454 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1455 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1456 * in driver load code to reflect the current hardware state of the crtc.
1458 * This is the native kms version of drm_vblank_on().
1460 void drm_crtc_vblank_on(struct drm_crtc *crtc)
1462 drm_vblank_on(crtc->dev, drm_crtc_index(crtc));
1464 EXPORT_SYMBOL(drm_crtc_vblank_on);
1467 * drm_vblank_pre_modeset - account for vblanks across mode sets
1471 * Account for vblank events across mode setting events, which will likely
1472 * reset the hardware frame counter.
1474 * This is done by grabbing a temporary vblank reference to ensure that the
1475 * vblank interrupt keeps running across the modeset sequence. With this the
1476 * software-side vblank frame counting will ensure that there are no jumps or
1479 * Unfortunately this approach is racy and also doesn't work when the vblank
1480 * interrupt stops running, e.g. across system suspend resume. It is therefore
1481 * highly recommended that drivers use the newer drm_vblank_off() and
1482 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1483 * using "cooked" software vblank frame counters and not relying on any hardware
1486 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1489 void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe)
1491 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1493 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1494 if (!dev->num_crtcs)
1497 if (WARN_ON(pipe >= dev->num_crtcs))
1501 * To avoid all the problems that might happen if interrupts
1502 * were enabled/disabled around or between these calls, we just
1503 * have the kernel take a reference on the CRTC (just once though
1504 * to avoid corrupting the count if multiple, mismatch calls occur),
1505 * so that interrupts remain enabled in the interim.
1507 if (!vblank->inmodeset) {
1508 vblank->inmodeset = 0x1;
1509 if (drm_vblank_get(dev, pipe) == 0)
1510 vblank->inmodeset |= 0x2;
1513 EXPORT_SYMBOL(drm_vblank_pre_modeset);
1516 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1520 * This function again drops the temporary vblank reference acquired in
1521 * drm_vblank_pre_modeset.
1523 void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe)
1525 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1526 unsigned long irqflags;
1528 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1529 if (!dev->num_crtcs)
1532 if (WARN_ON(pipe >= dev->num_crtcs))
1535 if (vblank->inmodeset) {
1536 spin_lock_irqsave(&dev->vbl_lock, irqflags);
1537 dev->vblank_disable_allowed = true;
1538 spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
1540 if (vblank->inmodeset & 0x2)
1541 drm_vblank_put(dev, pipe);
1543 vblank->inmodeset = 0;
1546 EXPORT_SYMBOL(drm_vblank_post_modeset);
1549 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1550 * @DRM_IOCTL_ARGS: standard ioctl arguments
1552 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1553 * ioctls around modesetting so that any lost vblank events are accounted for.
1555 * Generally the counter will reset across mode sets. If interrupts are
1556 * enabled around this call, we don't have to do anything since the counter
1557 * will have already been incremented.
1559 int drm_modeset_ctl(struct drm_device *dev, void *data,
1560 struct drm_file *file_priv)
1562 struct drm_modeset_ctl *modeset = data;
1565 /* If drm_vblank_init() hasn't been called yet, just no-op */
1566 if (!dev->num_crtcs)
1569 /* KMS drivers handle this internally */
1570 if (drm_core_check_feature(dev, DRIVER_MODESET))
1573 pipe = modeset->crtc;
1574 if (pipe >= dev->num_crtcs)
1577 switch (modeset->cmd) {
1578 case _DRM_PRE_MODESET:
1579 drm_vblank_pre_modeset(dev, pipe);
1581 case _DRM_POST_MODESET:
1582 drm_vblank_post_modeset(dev, pipe);
1591 static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe,
1592 union drm_wait_vblank *vblwait,
1593 struct drm_file *file_priv)
1595 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1596 struct drm_pending_vblank_event *e;
1598 unsigned long flags;
1602 e = kzalloc(sizeof(*e), GFP_KERNEL);
1609 e->base.pid = current->pid;
1610 e->event.base.type = DRM_EVENT_VBLANK;
1611 e->event.base.length = sizeof(e->event);
1612 e->event.user_data = vblwait->request.signal;
1613 e->base.event = &e->event.base;
1614 e->base.file_priv = file_priv;
1615 e->base.destroy = (void (*) (struct drm_pending_event *)) kfree;
1617 spin_lock_irqsave(&dev->event_lock, flags);
1620 * drm_vblank_off() might have been called after we called
1621 * drm_vblank_get(). drm_vblank_off() holds event_lock
1622 * around the vblank disable, so no need for further locking.
1623 * The reference from drm_vblank_get() protects against
1624 * vblank disable from another source.
1626 if (!vblank->enabled) {
1631 if (file_priv->event_space < sizeof(e->event)) {
1636 file_priv->event_space -= sizeof(e->event);
1637 seq = drm_vblank_count_and_time(dev, pipe, &now);
1639 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) &&
1640 (seq - vblwait->request.sequence) <= (1 << 23)) {
1641 vblwait->request.sequence = seq + 1;
1642 vblwait->reply.sequence = vblwait->request.sequence;
1645 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1646 vblwait->request.sequence, seq, pipe);
1648 trace_drm_vblank_event_queued(current->pid, pipe,
1649 vblwait->request.sequence);
1651 e->event.sequence = vblwait->request.sequence;
1652 if ((seq - vblwait->request.sequence) <= (1 << 23)) {
1653 drm_vblank_put(dev, pipe);
1654 send_vblank_event(dev, e, seq, &now);
1655 vblwait->reply.sequence = seq;
1657 /* drm_handle_vblank_events will call drm_vblank_put */
1658 list_add_tail(&e->base.link, &dev->vblank_event_list);
1659 vblwait->reply.sequence = vblwait->request.sequence;
1662 spin_unlock_irqrestore(&dev->event_lock, flags);
1667 spin_unlock_irqrestore(&dev->event_lock, flags);
1670 drm_vblank_put(dev, pipe);
1677 * \param inode device inode.
1678 * \param file_priv DRM file private.
1679 * \param cmd command.
1680 * \param data user argument, pointing to a drm_wait_vblank structure.
1681 * \return zero on success or a negative number on failure.
1683 * This function enables the vblank interrupt on the pipe requested, then
1684 * sleeps waiting for the requested sequence number to occur, and drops
1685 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1686 * after a timeout with no further vblank waits scheduled).
1688 int drm_wait_vblank(struct drm_device *dev, void *data,
1689 struct drm_file *file_priv)
1691 struct drm_vblank_crtc *vblank;
1692 union drm_wait_vblank *vblwait = data;
1694 unsigned int flags, seq, pipe, high_pipe;
1696 if (!dev->irq_enabled)
1699 if (vblwait->request.type & _DRM_VBLANK_SIGNAL)
1702 if (vblwait->request.type &
1703 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1704 _DRM_VBLANK_HIGH_CRTC_MASK)) {
1705 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1706 vblwait->request.type,
1707 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
1708 _DRM_VBLANK_HIGH_CRTC_MASK));
1712 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK;
1713 high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK);
1715 pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT;
1717 pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0;
1718 if (pipe >= dev->num_crtcs)
1721 vblank = &dev->vblank[pipe];
1723 ret = drm_vblank_get(dev, pipe);
1725 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret);
1728 seq = drm_vblank_count(dev, pipe);
1730 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) {
1731 case _DRM_VBLANK_RELATIVE:
1732 vblwait->request.sequence += seq;
1733 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE;
1734 case _DRM_VBLANK_ABSOLUTE:
1741 if (flags & _DRM_VBLANK_EVENT) {
1742 /* must hold on to the vblank ref until the event fires
1743 * drm_vblank_put will be called asynchronously
1745 return drm_queue_vblank_event(dev, pipe, vblwait, file_priv);
1748 if ((flags & _DRM_VBLANK_NEXTONMISS) &&
1749 (seq - vblwait->request.sequence) <= (1<<23)) {
1750 vblwait->request.sequence = seq + 1;
1753 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1754 vblwait->request.sequence, pipe);
1755 vblank->last_wait = vblwait->request.sequence;
1756 DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
1757 (((drm_vblank_count(dev, pipe) -
1758 vblwait->request.sequence) <= (1 << 23)) ||
1760 !dev->irq_enabled));
1762 if (ret != -EINTR) {
1765 vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now);
1766 vblwait->reply.tval_sec = now.tv_sec;
1767 vblwait->reply.tval_usec = now.tv_usec;
1769 DRM_DEBUG("returning %d to client\n",
1770 vblwait->reply.sequence);
1772 DRM_DEBUG("vblank wait interrupted by signal\n");
1776 drm_vblank_put(dev, pipe);
1780 static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe)
1782 struct drm_pending_vblank_event *e, *t;
1786 assert_spin_locked(&dev->event_lock);
1788 seq = drm_vblank_count_and_time(dev, pipe, &now);
1790 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) {
1791 if (e->pipe != pipe)
1793 if ((seq - e->event.sequence) > (1<<23))
1796 DRM_DEBUG("vblank event on %d, current %d\n",
1797 e->event.sequence, seq);
1799 list_del(&e->base.link);
1800 drm_vblank_put(dev, pipe);
1801 send_vblank_event(dev, e, seq, &now);
1804 trace_drm_vblank_event(pipe, seq);
1808 * drm_handle_vblank - handle a vblank event
1810 * @pipe: index of CRTC where this event occurred
1812 * Drivers should call this routine in their vblank interrupt handlers to
1813 * update the vblank counter and send any signals that may be pending.
1815 * This is the legacy version of drm_crtc_handle_vblank().
1817 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
1819 struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
1820 unsigned long irqflags;
1822 if (WARN_ON_ONCE(!dev->num_crtcs))
1825 if (WARN_ON(pipe >= dev->num_crtcs))
1828 spin_lock_irqsave(&dev->event_lock, irqflags);
1830 /* Need timestamp lock to prevent concurrent execution with
1831 * vblank enable/disable, as this would cause inconsistent
1832 * or corrupted timestamps and vblank counts.
1834 spin_lock(&dev->vblank_time_lock);
1836 /* Vblank irq handling disabled. Nothing to do. */
1837 if (!vblank->enabled) {
1838 spin_unlock(&dev->vblank_time_lock);
1839 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1843 drm_update_vblank_count(dev, pipe, DRM_CALLED_FROM_VBLIRQ);
1845 spin_unlock(&dev->vblank_time_lock);
1847 wake_up(&vblank->queue);
1848 drm_handle_vblank_events(dev, pipe);
1850 spin_unlock_irqrestore(&dev->event_lock, irqflags);
1854 EXPORT_SYMBOL(drm_handle_vblank);
1857 * drm_crtc_handle_vblank - handle a vblank event
1858 * @crtc: where this event occurred
1860 * Drivers should call this routine in their vblank interrupt handlers to
1861 * update the vblank counter and send any signals that may be pending.
1863 * This is the native KMS version of drm_handle_vblank().
1866 * True if the event was successfully handled, false on failure.
1868 bool drm_crtc_handle_vblank(struct drm_crtc *crtc)
1870 return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc));
1872 EXPORT_SYMBOL(drm_crtc_handle_vblank);
1875 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1877 * @pipe: CRTC for which to read the counter
1879 * Drivers can plug this into the .get_vblank_counter() function if
1880 * there is no useable hardware frame counter available.
1885 u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe)
1889 EXPORT_SYMBOL(drm_vblank_no_hw_counter);