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/slab.h>
41 #include <linux/export.h>
43 /* Access macro for slots in vblank timestamp ringbuffer. */
44 #define vblanktimestamp(dev, pipe, count) \
45 ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
47 /* Retry timestamp calculation up to 3 times to satisfy
48 * drm_timestamp_precision before giving up.
50 #define DRM_TIMESTAMP_MAXRETRIES 3
52 /* Threshold in nanoseconds for detection of redundant
53 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
55 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
58 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
59 struct timeval
*tvblank
, unsigned flags
);
61 unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
64 * Default to use monotonic timestamps for wait-for-vblank and page-flip
67 unsigned int drm_timestamp_monotonic
= 1;
69 int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
71 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
72 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
73 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
75 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
77 struct timeval
*t_vblank
, u32 last
)
79 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
82 assert_spin_locked(&dev
->vblank_time_lock
);
86 /* All writers hold the spinlock, but readers are serialized by
87 * the latching of vblank->count below.
89 tslot
= vblank
->count
+ vblank_count_inc
;
90 vblanktimestamp(dev
, pipe
, tslot
) = *t_vblank
;
93 * vblank timestamp updates are protected on the write side with
94 * vblank_time_lock, but on the read side done locklessly using a
95 * sequence-lock on the vblank counter. Ensure correct ordering using
96 * memory barrriers. We need the barrier both before and also after the
97 * counter update to synchronize with the next timestamp write.
98 * The read-side barriers for this are in drm_vblank_count_and_time.
101 vblank
->count
+= vblank_count_inc
;
106 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
108 * @pipe: index of CRTC for which to reset the timestamp
110 * Reset the stored timestamp for the current vblank count to correspond
111 * to the last vblank occurred.
113 * Only to be called from drm_vblank_on().
115 * Note: caller must hold dev->vbl_lock since this reads & writes
116 * device vblank fields.
118 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
122 struct timeval t_vblank
;
123 int count
= DRM_TIMESTAMP_MAXRETRIES
;
125 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
128 * sample the current counter to avoid random jumps
129 * when drm_vblank_enable() applies the diff
132 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
133 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
134 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
137 * Only reinitialize corresponding vblank timestamp if high-precision query
138 * available and didn't fail. Otherwise reinitialize delayed at next vblank
139 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
142 t_vblank
= (struct timeval
) {0, 0};
145 * +1 to make sure user will never see the same
146 * vblank counter value before and after a modeset
148 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
150 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
154 * drm_update_vblank_count - update the master vblank counter
156 * @pipe: counter to update
158 * Call back into the driver to update the appropriate vblank counter
159 * (specified by @pipe). Deal with wraparound, if it occurred, and
160 * update the last read value so we can deal with wraparound on the next
163 * Only necessary when going from off->on, to account for frames we
164 * didn't get an interrupt for.
166 * Note: caller must hold dev->vbl_lock since this reads & writes
167 * device vblank fields.
169 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
172 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
173 u32 cur_vblank
, diff
;
175 struct timeval t_vblank
;
176 int count
= DRM_TIMESTAMP_MAXRETRIES
;
177 int framedur_ns
= vblank
->framedur_ns
;
180 * Interrupts were disabled prior to this call, so deal with counter
182 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
183 * here if the register is small or we had vblank interrupts off for
186 * We repeat the hardware vblank counter & timestamp query until
187 * we get consistent results. This to prevent races between gpu
188 * updating its hardware counter while we are retrieving the
189 * corresponding vblank timestamp.
192 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
193 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
194 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
196 if (dev
->max_vblank_count
!= 0) {
197 /* trust the hw counter when it's around */
198 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
199 } else if (rc
&& framedur_ns
) {
200 const struct timeval
*t_old
;
203 t_old
= &vblanktimestamp(dev
, pipe
, vblank
->count
);
204 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
207 * Figure out how many vblanks we've missed based
208 * on the difference in the timestamps and the
209 * frame/field duration.
211 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
213 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
214 DRM_DEBUG("crtc %u: Redundant vblirq ignored."
215 " diff_ns = %lld, framedur_ns = %d)\n",
216 pipe
, (long long) diff_ns
, framedur_ns
);
218 /* some kind of default for drivers w/o accurate vbl timestamping */
219 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
222 DRM_DEBUG_VBLANK("updating vblank count on crtc %u:"
223 " current=%u, diff=%u, hw=%u hw_last=%u\n",
224 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
227 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
232 * Only reinitialize corresponding vblank timestamp if high-precision query
233 * available and didn't fail, or we were called from the vblank interrupt.
234 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
235 * for now, to mark the vblanktimestamp as invalid.
237 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
238 t_vblank
= (struct timeval
) {0, 0};
240 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
244 * Disable vblank irq's on crtc, make sure that last vblank count
245 * of hardware and corresponding consistent software vblank counter
246 * are preserved, even if there are any spurious vblank irq's after
249 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
251 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
252 unsigned long irqflags
;
254 /* Prevent vblank irq processing while disabling vblank irqs,
255 * so no updates of timestamps or count can happen after we've
256 * disabled. Needed to prevent races in case of delayed irq's.
258 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
261 * Only disable vblank interrupts if they're enabled. This avoids
262 * calling the ->disable_vblank() operation in atomic context with the
263 * hardware potentially runtime suspended.
265 if (vblank
->enabled
) {
266 dev
->driver
->disable_vblank(dev
, pipe
);
267 vblank
->enabled
= false;
271 * Always update the count and timestamp to maintain the
272 * appearance that the counter has been ticking all along until
273 * this time. This makes the count account for the entire time
274 * between drm_vblank_on() and drm_vblank_off().
276 drm_update_vblank_count(dev
, pipe
, 0);
278 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
281 static void vblank_disable_fn(unsigned long arg
)
283 struct drm_vblank_crtc
*vblank
= (void *)arg
;
284 struct drm_device
*dev
= vblank
->dev
;
285 unsigned int pipe
= vblank
->pipe
;
286 unsigned long irqflags
;
288 if (!dev
->vblank_disable_allowed
)
291 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
292 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
293 DRM_DEBUG_VBLANK("disabling vblank on crtc %u\n", pipe
);
294 vblank_disable_and_save(dev
, pipe
);
296 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
300 * drm_vblank_cleanup - cleanup vblank support
303 * This function cleans up any resources allocated in drm_vblank_init.
305 void drm_vblank_cleanup(struct drm_device
*dev
)
309 /* Bail if the driver didn't call drm_vblank_init() */
310 if (dev
->num_crtcs
== 0)
313 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
314 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
316 WARN_ON(vblank
->enabled
&&
317 drm_core_check_feature(dev
, DRIVER_MODESET
));
319 del_timer_sync(&vblank
->disable_timer
);
326 EXPORT_SYMBOL(drm_vblank_cleanup
);
329 * drm_vblank_init - initialize vblank support
331 * @num_crtcs: number of CRTCs supported by @dev
333 * This function initializes vblank support for @num_crtcs display pipelines.
336 * Zero on success or a negative error code on failure.
338 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
343 lockinit(&dev
->vbl_lock
, "drmvbl", 0, LK_CANRECURSE
);
344 lockinit(&dev
->vblank_time_lock
, "drmvtl", 0, LK_CANRECURSE
);
346 dev
->num_crtcs
= num_crtcs
;
348 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
352 for (i
= 0; i
< num_crtcs
; i
++) {
353 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
357 init_waitqueue_head(&vblank
->queue
);
358 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
359 (unsigned long)vblank
);
362 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
364 /* Driver specific high-precision vblank timestamping supported? */
365 if (dev
->driver
->get_vblank_timestamp
)
366 DRM_INFO("Driver supports precise vblank timestamp query.\n");
368 DRM_INFO("No driver support for vblank timestamp query.\n");
370 /* Must have precise timestamping for reliable vblank instant disable */
371 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
372 dev
->vblank_disable_immediate
= false;
373 DRM_INFO("Setting vblank_disable_immediate to false because "
374 "get_vblank_timestamp == NULL\n");
377 dev
->vblank_disable_allowed
= false;
385 EXPORT_SYMBOL(drm_vblank_init
);
388 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
390 struct drm_device
*dev
= cookie
;
392 if (dev
->driver
->vgaarb_irq
) {
393 dev
->driver
->vgaarb_irq(dev
, state
);
397 if (!dev
->irq_enabled
)
401 if (dev
->driver
->irq_uninstall
)
402 dev
->driver
->irq_uninstall(dev
);
404 if (dev
->driver
->irq_preinstall
)
405 dev
->driver
->irq_preinstall(dev
);
406 if (dev
->driver
->irq_postinstall
)
407 dev
->driver
->irq_postinstall(dev
);
413 * drm_irq_install - install IRQ handler
415 * @irq: IRQ number to install the handler for
417 * Initializes the IRQ related data. Installs the handler, calling the driver
418 * irq_preinstall() and irq_postinstall() functions before and after the
421 * This is the simplified helper interface provided for drivers with no special
422 * needs. Drivers which need to install interrupt handlers for multiple
423 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
424 * that vblank interrupts are available.
427 * Zero on success or a negative error code on failure.
429 int drm_irq_install(struct drm_device
*dev
, int irq
)
433 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
439 /* Driver must have been initialized */
440 if (!dev
->dev_private
)
443 if (dev
->irq_enabled
)
445 dev
->irq_enabled
= true;
447 DRM_DEBUG("irq=%d\n", irq
);
449 /* Before installing handler */
450 if (dev
->driver
->irq_preinstall
)
451 dev
->driver
->irq_preinstall(dev
);
453 /* Install handler */
454 ret
= -bus_setup_intr(dev
->dev
, dev
->irqr
, INTR_MPSAFE
,
455 dev
->driver
->irq_handler
, dev
, &dev
->irqh
, &dev
->irq_lock
);
458 dev
->irq_enabled
= false;
462 /* After installing handler */
463 if (dev
->driver
->irq_postinstall
)
464 ret
= dev
->driver
->irq_postinstall(dev
);
467 dev
->irq_enabled
= false;
468 bus_teardown_intr(dev
->dev
, dev
->irqr
, dev
->irqh
);
475 EXPORT_SYMBOL(drm_irq_install
);
478 * drm_irq_uninstall - uninstall the IRQ handler
481 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
482 * This should only be called by drivers which used drm_irq_install() to set up
483 * their interrupt handler. Other drivers must only reset
484 * drm_device->irq_enabled to false.
486 * Note that for kernel modesetting drivers it is a bug if this function fails.
487 * The sanity checks are only to catch buggy user modesetting drivers which call
488 * the same function through an ioctl.
491 * Zero on success or a negative error code on failure.
493 int drm_irq_uninstall(struct drm_device
*dev
)
495 unsigned long irqflags
;
499 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
502 irq_enabled
= dev
->irq_enabled
;
503 dev
->irq_enabled
= false;
506 * Wake up any waiters so they don't hang. This is just to paper over
507 * isssues for UMS drivers which aren't in full control of their
508 * vblank/irq handling. KMS drivers must ensure that vblanks are all
509 * disabled when uninstalling the irq handler.
511 if (dev
->num_crtcs
) {
512 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
513 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
514 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
516 if (!vblank
->enabled
)
519 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
521 vblank_disable_and_save(dev
, i
);
522 wake_up(&vblank
->queue
);
524 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
530 DRM_DEBUG("irq=%d\n", dev
->irq
);
532 if (dev
->driver
->irq_uninstall
)
533 dev
->driver
->irq_uninstall(dev
);
535 bus_teardown_intr(dev
->dev
, dev
->irqr
, dev
->irqh
);
539 EXPORT_SYMBOL(drm_irq_uninstall
);
544 * \param inode device inode.
545 * \param file_priv DRM file private.
546 * \param cmd command.
547 * \param arg user argument, pointing to a drm_control structure.
548 * \return zero on success or a negative number on failure.
550 * Calls irq_install() or irq_uninstall() according to \p arg.
552 int drm_control(struct drm_device
*dev
, void *data
,
553 struct drm_file
*file_priv
)
555 struct drm_control
*ctl
= data
;
558 /* if we haven't irq we fallback for compatibility reasons -
559 * this used to be a separate function in drm_dma.h
562 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
564 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
566 /* UMS was only ever support on pci devices. */
567 if (WARN_ON(!dev
->pdev
))
571 case DRM_INST_HANDLER
:
574 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
577 mutex_lock(&dev
->struct_mutex
);
578 ret
= drm_irq_install(dev
, irq
);
579 mutex_unlock(&dev
->struct_mutex
);
582 case DRM_UNINST_HANDLER
:
583 mutex_lock(&dev
->struct_mutex
);
584 ret
= drm_irq_uninstall(dev
);
585 mutex_unlock(&dev
->struct_mutex
);
594 * drm_calc_timestamping_constants - calculate vblank timestamp constants
595 * @crtc: drm_crtc whose timestamp constants should be updated.
596 * @mode: display mode containing the scanout timings
598 * Calculate and store various constants which are later
599 * needed by vblank and swap-completion timestamping, e.g,
600 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
601 * derived from CRTC's true scanout timing, so they take
602 * things like panel scaling or other adjustments into account.
604 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
605 const struct drm_display_mode
*mode
)
607 struct drm_device
*dev
= crtc
->dev
;
608 unsigned int pipe
= drm_crtc_index(crtc
);
609 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
610 int linedur_ns
= 0, framedur_ns
= 0;
611 int dotclock
= mode
->crtc_clock
;
616 if (WARN_ON(pipe
>= dev
->num_crtcs
))
619 /* Valid dotclock? */
621 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
624 * Convert scanline length in pixels and video
625 * dot clock to line duration and frame duration
628 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
629 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
632 * Fields of interlaced scanout modes are only half a frame duration.
634 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
637 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
640 vblank
->linedur_ns
= linedur_ns
;
641 vblank
->framedur_ns
= framedur_ns
;
643 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
644 crtc
->base
.id
, mode
->crtc_htotal
,
645 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
646 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
647 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
649 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
652 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
654 * @pipe: index of CRTC whose vblank timestamp to retrieve
655 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
656 * On return contains true maximum error of timestamp
657 * @vblank_time: Pointer to struct timeval which should receive the timestamp
658 * @flags: Flags to pass to driver:
660 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
661 * @mode: mode which defines the scanout timings
663 * Implements calculation of exact vblank timestamps from given drm_display_mode
664 * timings and current video scanout position of a CRTC. This can be called from
665 * within get_vblank_timestamp() implementation of a kms driver to implement the
666 * actual timestamping.
668 * Should return timestamps conforming to the OML_sync_control OpenML
669 * extension specification. The timestamp corresponds to the end of
670 * the vblank interval, aka start of scanout of topmost-leftmost display
671 * pixel in the following video frame.
673 * Requires support for optional dev->driver->get_scanout_position()
674 * in kms driver, plus a bit of setup code to provide a drm_display_mode
675 * that corresponds to the true scanout timing.
677 * The current implementation only handles standard video modes. It
678 * returns as no operation if a doublescan or interlaced video mode is
679 * active. Higher level code is expected to handle this.
682 * Negative value on error, failure or if not supported in current
685 * -EINVAL - Invalid CRTC.
686 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
687 * -ENOTSUPP - Function not supported in current display mode.
688 * -EIO - Failed, e.g., due to failed scanout position query.
690 * Returns or'ed positive status flags on success:
692 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
693 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
696 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
699 struct timeval
*vblank_time
,
701 const struct drm_display_mode
*mode
)
703 struct timeval tv_etime
;
704 ktime_t stime
, etime
;
705 unsigned int vbl_status
;
706 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
708 int delta_ns
, duration_ns
;
710 if (pipe
>= dev
->num_crtcs
) {
711 DRM_ERROR("Invalid crtc %u\n", pipe
);
715 /* Scanout position query not supported? Should not happen. */
716 if (!dev
->driver
->get_scanout_position
) {
717 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
721 /* If mode timing undefined, just return as no-op:
722 * Happens during initial modesetting of a crtc.
724 if (mode
->crtc_clock
== 0) {
725 DRM_DEBUG_VBLANK("crtc %u: Noop due to uninitialized mode.\n", pipe
);
729 /* Get current scanout position with system timestamp.
730 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
731 * if single query takes longer than max_error nanoseconds.
733 * This guarantees a tight bound on maximum error if
734 * code gets preempted or delayed for some reason.
736 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
738 * Get vertical and horizontal scanout position vpos, hpos,
739 * and bounding timestamps stime, etime, pre/post query.
741 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
746 /* Return as no-op if scanout query unsupported or failed. */
747 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
748 DRM_DEBUG_VBLANK("crtc %u : scanoutpos query failed [0x%x].\n",
753 /* Compute uncertainty in timestamp of scanout position query. */
754 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
756 /* Accept result with < max_error nsecs timing uncertainty. */
757 if (duration_ns
<= *max_error
)
761 /* Noisy system timing? */
762 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
763 DRM_DEBUG_VBLANK("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
764 pipe
, duration_ns
/1000, *max_error
/1000, i
);
767 /* Return upper bound of timestamp precision error. */
768 *max_error
= duration_ns
;
770 /* Check if in vblank area:
771 * vpos is >=0 in video scanout area, but negative
772 * within vblank area, counting down the number of lines until
775 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
776 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
778 /* Convert scanout position into elapsed time at raw_time query
779 * since start of scanout at first display scanline. delta_ns
780 * can be negative if start of scanout hasn't happened yet.
782 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
785 if (!drm_timestamp_monotonic
)
786 etime
= ktime_mono_to_real(etime
);
788 /* save this only for debugging purposes */
789 tv_etime
= ktime_to_timeval(etime
);
790 /* Subtract time delta from raw timestamp to get final
791 * vblank_time timestamp for end of vblank.
794 etime
= ktime_add_ns(etime
, -delta_ns
);
796 etime
= ktime_sub_ns(etime
, delta_ns
);
797 *vblank_time
= ktime_to_timeval(etime
);
799 DRM_DEBUG_VBLANK("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
800 pipe
, vbl_status
, hpos
, vpos
,
801 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
802 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
803 duration_ns
/1000, i
);
807 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
809 static struct timeval
get_drm_timestamp(void)
813 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
814 return ktime_to_timeval(now
);
818 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
821 * @pipe: index of CRTC whose vblank timestamp to retrieve
822 * @tvblank: Pointer to target struct timeval which should receive the timestamp
823 * @flags: Flags to pass to driver:
825 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
827 * Fetches the system timestamp corresponding to the time of the most recent
828 * vblank interval on specified CRTC. May call into kms-driver to
829 * compute the timestamp with a high-precision GPU specific method.
831 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
832 * call, i.e., it isn't very precisely locked to the true vblank.
835 * True if timestamp is considered to be very precise, false otherwise.
838 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
839 struct timeval
*tvblank
, unsigned flags
)
843 /* Define requested maximum error on timestamps (nanoseconds). */
844 int max_error
= (int) drm_timestamp_precision
* 1000;
846 /* Query driver if possible and precision timestamping enabled. */
847 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
848 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
854 /* GPU high precision timestamp query unsupported or failed.
855 * Return current monotonic/gettimeofday timestamp as best estimate.
857 *tvblank
= get_drm_timestamp();
863 * drm_vblank_count - retrieve "cooked" vblank counter value
865 * @pipe: index of CRTC for which to retrieve the counter
867 * Fetches the "cooked" vblank count value that represents the number of
868 * vblank events since the system was booted, including lost events due to
869 * modesetting activity.
871 * This is the legacy version of drm_crtc_vblank_count().
874 * The software vblank counter.
876 u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
878 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
880 if (WARN_ON(pipe
>= dev
->num_crtcs
))
883 return vblank
->count
;
885 EXPORT_SYMBOL(drm_vblank_count
);
888 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
889 * @crtc: which counter to retrieve
891 * Fetches the "cooked" vblank count value that represents the number of
892 * vblank events since the system was booted, including lost events due to
893 * modesetting activity.
895 * This is the native KMS version of drm_vblank_count().
898 * The software vblank counter.
900 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
902 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
904 EXPORT_SYMBOL(drm_crtc_vblank_count
);
907 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
908 * system timestamp corresponding to that vblank counter value.
910 * @pipe: index of CRTC whose counter to retrieve
911 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
913 * Fetches the "cooked" vblank count value that represents the number of
914 * vblank events since the system was booted, including lost events due to
915 * modesetting activity. Returns corresponding system timestamp of the time
916 * of the vblank interval that corresponds to the current vblank counter value.
918 * This is the legacy version of drm_crtc_vblank_count_and_time().
920 u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
921 struct timeval
*vblanktime
)
923 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
924 int count
= DRM_TIMESTAMP_MAXRETRIES
;
927 vblanktime
->tv_sec
= 0; /* silence gcc warning */
928 vblanktime
->tv_usec
= 0; /* silence gcc warning */
929 if (WARN_ON(pipe
>= dev
->num_crtcs
))
933 * Vblank timestamps are read lockless. To ensure consistency the vblank
934 * counter is rechecked and ordering is ensured using memory barriers.
935 * This works like a seqlock. The write-side barriers are in store_vblank.
938 cur_vblank
= vblank
->count
;
940 *vblanktime
= vblanktimestamp(dev
, pipe
, cur_vblank
);
942 } while (cur_vblank
!= vblank
->count
&& --count
> 0);
946 EXPORT_SYMBOL(drm_vblank_count_and_time
);
949 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
950 * and the system timestamp corresponding to that vblank counter value
951 * @crtc: which counter to retrieve
952 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
954 * Fetches the "cooked" vblank count value that represents the number of
955 * vblank events since the system was booted, including lost events due to
956 * modesetting activity. Returns corresponding system timestamp of the time
957 * of the vblank interval that corresponds to the current vblank counter value.
959 * This is the native KMS version of drm_vblank_count_and_time().
961 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
962 struct timeval
*vblanktime
)
964 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
967 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
969 static void send_vblank_event(struct drm_device
*dev
,
970 struct drm_pending_vblank_event
*e
,
971 unsigned long seq
, struct timeval
*now
)
973 assert_spin_locked(&dev
->event_lock
);
975 e
->event
.sequence
= seq
;
976 e
->event
.tv_sec
= now
->tv_sec
;
977 e
->event
.tv_usec
= now
->tv_usec
;
979 list_add_tail(&e
->base
.link
,
980 &e
->base
.file_priv
->event_list
);
981 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
983 KNOTE(&e
->base
.file_priv
->dkq
.ki_note
, 0);
985 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
990 * drm_arm_vblank_event - arm vblank event after pageflip
993 * @e: the event to prepare to send
995 * A lot of drivers need to generate vblank events for the very next vblank
996 * interrupt. For example when the page flip interrupt happens when the page
997 * flip gets armed, but not when it actually executes within the next vblank
998 * period. This helper function implements exactly the required vblank arming
1001 * Caller must hold event lock. Caller must also hold a vblank reference for
1002 * the event @e, which will be dropped when the next vblank arrives.
1004 * This is the legacy version of drm_crtc_arm_vblank_event().
1006 void drm_arm_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1007 struct drm_pending_vblank_event
*e
)
1009 assert_spin_locked(&dev
->event_lock
);
1012 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1013 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1015 EXPORT_SYMBOL(drm_arm_vblank_event
);
1018 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1019 * @crtc: the source CRTC of the vblank event
1020 * @e: the event to send
1022 * A lot of drivers need to generate vblank events for the very next vblank
1023 * interrupt. For example when the page flip interrupt happens when the page
1024 * flip gets armed, but not when it actually executes within the next vblank
1025 * period. This helper function implements exactly the required vblank arming
1028 * Caller must hold event lock. Caller must also hold a vblank reference for
1029 * the event @e, which will be dropped when the next vblank arrives.
1031 * This is the native KMS version of drm_arm_vblank_event().
1033 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1034 struct drm_pending_vblank_event
*e
)
1036 drm_arm_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1038 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1041 * drm_send_vblank_event - helper to send vblank event after pageflip
1044 * @e: the event to send
1046 * Updates sequence # and timestamp on event, and sends it to userspace.
1047 * Caller must hold event lock.
1049 * This is the legacy version of drm_crtc_send_vblank_event().
1051 void drm_send_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1052 struct drm_pending_vblank_event
*e
)
1057 if (dev
->num_crtcs
> 0) {
1058 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1062 now
= get_drm_timestamp();
1065 send_vblank_event(dev
, e
, seq
, &now
);
1067 EXPORT_SYMBOL(drm_send_vblank_event
);
1070 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1071 * @crtc: the source CRTC of the vblank event
1072 * @e: the event to send
1074 * Updates sequence # and timestamp on event, and sends it to userspace.
1075 * Caller must hold event lock.
1077 * This is the native KMS version of drm_send_vblank_event().
1079 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1080 struct drm_pending_vblank_event
*e
)
1082 drm_send_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1084 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1087 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1092 * Zero on success or a negative error code on failure.
1094 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1096 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1099 assert_spin_locked(&dev
->vbl_lock
);
1101 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1103 if (!vblank
->enabled
) {
1105 * Enable vblank irqs under vblank_time_lock protection.
1106 * All vblank count & timestamp updates are held off
1107 * until we are done reinitializing master counter and
1108 * timestamps. Filtercode in drm_handle_vblank() will
1109 * prevent double-accounting of same vblank interval.
1111 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1112 DRM_DEBUG_VBLANK("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1114 atomic_dec(&vblank
->refcount
);
1116 vblank
->enabled
= true;
1117 drm_update_vblank_count(dev
, pipe
, 0);
1121 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1127 * drm_vblank_get - get a reference count on vblank events
1129 * @pipe: index of CRTC to own
1131 * Acquire a reference count on vblank events to avoid having them disabled
1134 * This is the legacy version of drm_crtc_vblank_get().
1137 * Zero on success or a negative error code on failure.
1139 int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1141 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1142 unsigned long irqflags
;
1145 if (!dev
->num_crtcs
)
1148 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1151 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1152 /* Going from 0->1 means we have to enable interrupts again */
1153 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1154 ret
= drm_vblank_enable(dev
, pipe
);
1156 if (!vblank
->enabled
) {
1157 atomic_dec(&vblank
->refcount
);
1161 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1165 EXPORT_SYMBOL(drm_vblank_get
);
1168 * drm_crtc_vblank_get - get a reference count on vblank events
1169 * @crtc: which CRTC to own
1171 * Acquire a reference count on vblank events to avoid having them disabled
1174 * This is the native kms version of drm_vblank_get().
1177 * Zero on success or a negative error code on failure.
1179 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1181 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1183 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1186 * drm_vblank_put - release ownership of vblank events
1188 * @pipe: index of CRTC to release
1190 * Release ownership of a given vblank counter, turning off interrupts
1191 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1193 * This is the legacy version of drm_crtc_vblank_put().
1195 void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1197 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1199 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1202 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1205 /* Last user schedules interrupt disable */
1206 if (atomic_dec_and_test(&vblank
->refcount
)) {
1207 if (drm_vblank_offdelay
== 0)
1209 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1210 vblank_disable_fn((unsigned long)vblank
);
1212 mod_timer(&vblank
->disable_timer
,
1213 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1216 EXPORT_SYMBOL(drm_vblank_put
);
1219 * drm_crtc_vblank_put - give up ownership of vblank events
1220 * @crtc: which counter to give up
1222 * Release ownership of a given vblank counter, turning off interrupts
1223 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1225 * This is the native kms version of drm_vblank_put().
1227 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1229 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1231 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1234 * drm_wait_one_vblank - wait for one vblank
1238 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1239 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1240 * due to lack of driver support or because the crtc is off.
1242 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1244 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1248 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1251 ret
= drm_vblank_get(dev
, pipe
);
1252 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1255 last
= drm_vblank_count(dev
, pipe
);
1257 ret
= wait_event_timeout(vblank
->queue
,
1258 last
!= drm_vblank_count(dev
, pipe
),
1259 msecs_to_jiffies(100));
1261 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1263 drm_vblank_put(dev
, pipe
);
1265 EXPORT_SYMBOL(drm_wait_one_vblank
);
1268 * drm_crtc_wait_one_vblank - wait for one vblank
1271 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1272 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1273 * due to lack of driver support or because the crtc is off.
1275 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1277 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1279 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1282 * drm_vblank_off - disable vblank events on a CRTC
1286 * Drivers can use this function to shut down the vblank interrupt handling when
1287 * disabling a crtc. This function ensures that the latest vblank frame count is
1288 * stored so that drm_vblank_on() can restore it again.
1290 * Drivers must use this function when the hardware vblank counter can get
1291 * reset, e.g. when suspending.
1293 * This is the legacy version of drm_crtc_vblank_off().
1295 void drm_vblank_off(struct drm_device
*dev
, unsigned int pipe
)
1297 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1298 struct drm_pending_vblank_event
*e
, *t
;
1300 unsigned long irqflags
;
1303 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1306 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1308 lockmgr(&dev
->vbl_lock
, LK_EXCLUSIVE
);
1309 vblank_disable_and_save(dev
, pipe
);
1310 wake_up(&vblank
->queue
);
1313 * Prevent subsequent drm_vblank_get() from re-enabling
1314 * the vblank interrupt by bumping the refcount.
1316 if (!vblank
->inmodeset
) {
1317 atomic_inc(&vblank
->refcount
);
1318 vblank
->inmodeset
= 1;
1320 lockmgr(&dev
->vbl_lock
, LK_RELEASE
);
1322 /* Send any queued vblank events, lest the natives grow disquiet */
1323 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1325 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1326 if (e
->pipe
!= pipe
)
1328 DRM_DEBUG_VBLANK("Sending premature vblank event on disable: \
1329 wanted %d, current %d\n",
1330 e
->event
.sequence
, seq
);
1331 list_del(&e
->base
.link
);
1332 drm_vblank_put(dev
, pipe
);
1333 send_vblank_event(dev
, e
, seq
, &now
);
1335 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1337 EXPORT_SYMBOL(drm_vblank_off
);
1340 * drm_crtc_vblank_off - disable vblank events on a CRTC
1341 * @crtc: CRTC in question
1343 * Drivers can use this function to shut down the vblank interrupt handling when
1344 * disabling a crtc. This function ensures that the latest vblank frame count is
1345 * stored so that drm_vblank_on can restore it again.
1347 * Drivers must use this function when the hardware vblank counter can get
1348 * reset, e.g. when suspending.
1350 * This is the native kms version of drm_vblank_off().
1352 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1354 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1356 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1359 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1360 * @crtc: CRTC in question
1362 * Drivers can use this function to reset the vblank state to off at load time.
1363 * Drivers should use this together with the drm_crtc_vblank_off() and
1364 * drm_crtc_vblank_on() functions. The difference compared to
1365 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1366 * and hence doesn't need to call any driver hooks.
1368 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1370 struct drm_device
*dev
= crtc
->dev
;
1371 unsigned long irqflags
;
1372 unsigned int pipe
= drm_crtc_index(crtc
);
1373 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1375 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1377 * Prevent subsequent drm_vblank_get() from enabling the vblank
1378 * interrupt by bumping the refcount.
1380 if (!vblank
->inmodeset
) {
1381 atomic_inc(&vblank
->refcount
);
1382 vblank
->inmodeset
= 1;
1384 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1386 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1388 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1391 * drm_vblank_on - enable vblank events on a CRTC
1395 * This functions restores the vblank interrupt state captured with
1396 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1397 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1398 * in driver load code to reflect the current hardware state of the crtc.
1400 * This is the legacy version of drm_crtc_vblank_on().
1402 void drm_vblank_on(struct drm_device
*dev
, unsigned int pipe
)
1404 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1405 unsigned long irqflags
;
1407 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1410 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1411 /* Drop our private "prevent drm_vblank_get" refcount */
1412 if (vblank
->inmodeset
) {
1413 atomic_dec(&vblank
->refcount
);
1414 vblank
->inmodeset
= 0;
1417 drm_reset_vblank_timestamp(dev
, pipe
);
1420 * re-enable interrupts if there are users left, or the
1421 * user wishes vblank interrupts to be enabled all the time.
1423 if (atomic_read(&vblank
->refcount
) != 0 ||
1424 (!dev
->vblank_disable_immediate
&& drm_vblank_offdelay
== 0))
1425 WARN_ON(drm_vblank_enable(dev
, pipe
));
1426 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1428 EXPORT_SYMBOL(drm_vblank_on
);
1431 * drm_crtc_vblank_on - enable vblank events on a CRTC
1432 * @crtc: CRTC in question
1434 * This functions restores the vblank interrupt state captured with
1435 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1436 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1437 * in driver load code to reflect the current hardware state of the crtc.
1439 * This is the native kms version of drm_vblank_on().
1441 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1443 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1445 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1448 * drm_vblank_pre_modeset - account for vblanks across mode sets
1452 * Account for vblank events across mode setting events, which will likely
1453 * reset the hardware frame counter.
1455 * This is done by grabbing a temporary vblank reference to ensure that the
1456 * vblank interrupt keeps running across the modeset sequence. With this the
1457 * software-side vblank frame counting will ensure that there are no jumps or
1460 * Unfortunately this approach is racy and also doesn't work when the vblank
1461 * interrupt stops running, e.g. across system suspend resume. It is therefore
1462 * highly recommended that drivers use the newer drm_vblank_off() and
1463 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1464 * using "cooked" software vblank frame counters and not relying on any hardware
1467 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1470 void drm_vblank_pre_modeset(struct drm_device
*dev
, unsigned int pipe
)
1472 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1474 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1475 if (!dev
->num_crtcs
)
1478 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1482 * To avoid all the problems that might happen if interrupts
1483 * were enabled/disabled around or between these calls, we just
1484 * have the kernel take a reference on the CRTC (just once though
1485 * to avoid corrupting the count if multiple, mismatch calls occur),
1486 * so that interrupts remain enabled in the interim.
1488 if (!vblank
->inmodeset
) {
1489 vblank
->inmodeset
= 0x1;
1490 if (drm_vblank_get(dev
, pipe
) == 0)
1491 vblank
->inmodeset
|= 0x2;
1494 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1497 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1501 * This function again drops the temporary vblank reference acquired in
1502 * drm_vblank_pre_modeset.
1504 void drm_vblank_post_modeset(struct drm_device
*dev
, unsigned int pipe
)
1506 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1507 unsigned long irqflags
;
1509 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1510 if (!dev
->num_crtcs
)
1513 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1516 if (vblank
->inmodeset
) {
1517 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1518 dev
->vblank_disable_allowed
= true;
1519 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1521 if (vblank
->inmodeset
& 0x2)
1522 drm_vblank_put(dev
, pipe
);
1524 vblank
->inmodeset
= 0;
1527 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1530 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1531 * @DRM_IOCTL_ARGS: standard ioctl arguments
1533 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1534 * ioctls around modesetting so that any lost vblank events are accounted for.
1536 * Generally the counter will reset across mode sets. If interrupts are
1537 * enabled around this call, we don't have to do anything since the counter
1538 * will have already been incremented.
1540 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1541 struct drm_file
*file_priv
)
1543 struct drm_modeset_ctl
*modeset
= data
;
1546 /* If drm_vblank_init() hasn't been called yet, just no-op */
1547 if (!dev
->num_crtcs
)
1550 /* KMS drivers handle this internally */
1551 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1554 pipe
= modeset
->crtc
;
1555 if (pipe
>= dev
->num_crtcs
)
1558 switch (modeset
->cmd
) {
1559 case _DRM_PRE_MODESET
:
1560 drm_vblank_pre_modeset(dev
, pipe
);
1562 case _DRM_POST_MODESET
:
1563 drm_vblank_post_modeset(dev
, pipe
);
1572 #ifdef __DragonFly__
1574 * The Linux layer version of kfree() is a macro and can't be called
1575 * directly via a function pointer
1578 drm_vblank_event_destroy(struct drm_pending_event
*e
)
1584 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1585 union drm_wait_vblank
*vblwait
,
1586 struct drm_file
*file_priv
)
1588 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1589 struct drm_pending_vblank_event
*e
;
1591 unsigned long flags
;
1595 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1602 e
->base
.pid
= curproc
->p_pid
;
1603 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1604 e
->event
.base
.length
= sizeof(e
->event
);
1605 e
->event
.user_data
= vblwait
->request
.signal
;
1606 e
->base
.event
= &e
->event
.base
;
1607 e
->base
.file_priv
= file_priv
;
1608 #ifdef __DragonFly__
1609 e
->base
.destroy
= drm_vblank_event_destroy
;
1611 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1614 spin_lock_irqsave(&dev
->event_lock
, flags
);
1617 * drm_vblank_off() might have been called after we called
1618 * drm_vblank_get(). drm_vblank_off() holds event_lock
1619 * around the vblank disable, so no need for further locking.
1620 * The reference from drm_vblank_get() protects against
1621 * vblank disable from another source.
1623 if (!vblank
->enabled
) {
1628 if (file_priv
->event_space
< sizeof(e
->event
)) {
1633 file_priv
->event_space
-= sizeof(e
->event
);
1634 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1636 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1637 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1638 vblwait
->request
.sequence
= seq
+ 1;
1639 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1642 DRM_DEBUG_VBLANK("event on vblank count %d, current %d, crtc %u\n",
1643 vblwait
->request
.sequence
, seq
, pipe
);
1645 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1646 vblwait
->request
.sequence
);
1648 e
->event
.sequence
= vblwait
->request
.sequence
;
1649 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1650 drm_vblank_put(dev
, pipe
);
1651 send_vblank_event(dev
, e
, seq
, &now
);
1652 vblwait
->reply
.sequence
= seq
;
1654 /* drm_handle_vblank_events will call drm_vblank_put */
1655 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1656 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1659 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1664 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1667 drm_vblank_put(dev
, pipe
);
1674 * \param inode device inode.
1675 * \param file_priv DRM file private.
1676 * \param cmd command.
1677 * \param data user argument, pointing to a drm_wait_vblank structure.
1678 * \return zero on success or a negative number on failure.
1680 * This function enables the vblank interrupt on the pipe requested, then
1681 * sleeps waiting for the requested sequence number to occur, and drops
1682 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1683 * after a timeout with no further vblank waits scheduled).
1685 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1686 struct drm_file
*file_priv
)
1688 struct drm_vblank_crtc
*vblank
;
1689 union drm_wait_vblank
*vblwait
= data
;
1691 unsigned int flags
, seq
, pipe
, high_pipe
;
1693 if (!dev
->irq_enabled
)
1696 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1699 if (vblwait
->request
.type
&
1700 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1701 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1702 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1703 vblwait
->request
.type
,
1704 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1705 _DRM_VBLANK_HIGH_CRTC_MASK
));
1709 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1710 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1712 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1714 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1715 if (pipe
>= dev
->num_crtcs
)
1718 vblank
= &dev
->vblank
[pipe
];
1720 ret
= drm_vblank_get(dev
, pipe
);
1722 DRM_DEBUG_VBLANK("failed to acquire vblank counter, %d\n", ret
);
1725 seq
= drm_vblank_count(dev
, pipe
);
1727 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1728 case _DRM_VBLANK_RELATIVE
:
1729 vblwait
->request
.sequence
+= seq
;
1730 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1731 case _DRM_VBLANK_ABSOLUTE
:
1738 if (flags
& _DRM_VBLANK_EVENT
) {
1739 /* must hold on to the vblank ref until the event fires
1740 * drm_vblank_put will be called asynchronously
1742 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1745 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1746 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1747 vblwait
->request
.sequence
= seq
+ 1;
1750 DRM_DEBUG_VBLANK("waiting on vblank count %d, crtc %u\n",
1751 vblwait
->request
.sequence
, pipe
);
1752 vblank
->last_wait
= vblwait
->request
.sequence
;
1753 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1754 (((drm_vblank_count(dev
, pipe
) -
1755 vblwait
->request
.sequence
) <= (1 << 23)) ||
1757 !dev
->irq_enabled
));
1759 if (ret
!= -EINTR
) {
1762 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1763 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1764 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1766 DRM_DEBUG_VBLANK("returning %d to client\n",
1767 vblwait
->reply
.sequence
);
1769 DRM_DEBUG_VBLANK("vblank wait interrupted by signal\n");
1773 drm_vblank_put(dev
, pipe
);
1777 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1779 struct drm_pending_vblank_event
*e
, *t
;
1783 assert_spin_locked(&dev
->event_lock
);
1785 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1787 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1788 if (e
->pipe
!= pipe
)
1790 if ((seq
- e
->event
.sequence
) > (1<<23))
1793 DRM_DEBUG_VBLANK("vblank event on %d, current %d\n",
1794 e
->event
.sequence
, seq
);
1796 list_del(&e
->base
.link
);
1797 drm_vblank_put(dev
, pipe
);
1798 send_vblank_event(dev
, e
, seq
, &now
);
1801 trace_drm_vblank_event(pipe
, seq
);
1805 * drm_handle_vblank - handle a vblank event
1807 * @pipe: index of CRTC where this event occurred
1809 * Drivers should call this routine in their vblank interrupt handlers to
1810 * update the vblank counter and send any signals that may be pending.
1812 * This is the legacy version of drm_crtc_handle_vblank().
1814 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1816 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1817 unsigned long irqflags
;
1819 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1822 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1825 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1827 /* Need timestamp lock to prevent concurrent execution with
1828 * vblank enable/disable, as this would cause inconsistent
1829 * or corrupted timestamps and vblank counts.
1831 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1833 /* Vblank irq handling disabled. Nothing to do. */
1834 if (!vblank
->enabled
) {
1835 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1836 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1840 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1842 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1844 wake_up(&vblank
->queue
);
1845 drm_handle_vblank_events(dev
, pipe
);
1847 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1851 EXPORT_SYMBOL(drm_handle_vblank
);
1854 * drm_crtc_handle_vblank - handle a vblank event
1855 * @crtc: where this event occurred
1857 * Drivers should call this routine in their vblank interrupt handlers to
1858 * update the vblank counter and send any signals that may be pending.
1860 * This is the native KMS version of drm_handle_vblank().
1863 * True if the event was successfully handled, false on failure.
1865 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1867 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1869 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1872 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1874 * @pipe: CRTC for which to read the counter
1876 * Drivers can plug this into the .get_vblank_counter() function if
1877 * there is no useable hardware frame counter available.
1882 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1886 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);