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, crtc, count) \
47 ((dev)->vblank[crtc].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
, int crtc
,
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);
78 * drm_update_vblank_count - update the master vblank counter
80 * @crtc: counter to update
82 * Call back into the driver to update the appropriate vblank counter
83 * (specified by @crtc). Deal with wraparound, if it occurred, and
84 * update the last read value so we can deal with wraparound on the next
87 * Only necessary when going from off->on, to account for frames we
88 * didn't get an interrupt for.
90 * Note: caller must hold dev->vbl_lock since this reads & writes
91 * device vblank fields.
93 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
95 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
96 u32 cur_vblank
, diff
, tslot
;
98 struct timeval t_vblank
;
101 * Interrupts were disabled prior to this call, so deal with counter
103 * NOTE! It's possible we lost a full dev->max_vblank_count events
104 * here if the register is small or we had vblank interrupts off for
107 * We repeat the hardware vblank counter & timestamp query until
108 * we get consistent results. This to prevent races between gpu
109 * updating its hardware counter while we are retrieving the
110 * corresponding vblank timestamp.
113 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
114 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
115 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
117 /* Deal with counter wrap */
118 diff
= cur_vblank
- vblank
->last
;
119 if (cur_vblank
< vblank
->last
) {
120 diff
+= dev
->max_vblank_count
;
122 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
123 crtc
, vblank
->last
, cur_vblank
, diff
);
126 DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
132 /* Reinitialize corresponding vblank timestamp if high-precision query
133 * available. Skip this step if query unsupported or failed. Will
134 * reinitialize delayed at next vblank interrupt in that case.
137 tslot
= atomic_read(&vblank
->count
) + diff
;
138 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
141 smp_mb__before_atomic();
142 atomic_add(diff
, &vblank
->count
);
143 smp_mb__after_atomic();
147 * Disable vblank irq's on crtc, make sure that last vblank count
148 * of hardware and corresponding consistent software vblank counter
149 * are preserved, even if there are any spurious vblank irq's after
152 static void vblank_disable_and_save(struct drm_device
*dev
, int crtc
)
154 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
155 unsigned long irqflags
;
159 struct timeval tvblank
;
160 int count
= DRM_TIMESTAMP_MAXRETRIES
;
162 /* Prevent vblank irq processing while disabling vblank irqs,
163 * so no updates of timestamps or count can happen after we've
164 * disabled. Needed to prevent races in case of delayed irq's.
166 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
169 * If the vblank interrupt was already disbled update the count
170 * and timestamp to maintain the appearance that the counter
171 * has been ticking all along until this time. This makes the
172 * count account for the entire time between drm_vblank_on() and
175 * But only do this if precise vblank timestamps are available.
176 * Otherwise we might read a totally bogus timestamp since drivers
177 * lacking precise timestamp support rely upon sampling the system clock
178 * at vblank interrupt time. Which obviously won't work out well if the
179 * vblank interrupt is disabled.
181 if (!vblank
->enabled
&&
182 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, 0)) {
183 drm_update_vblank_count(dev
, crtc
);
184 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
188 dev
->driver
->disable_vblank(dev
, crtc
);
189 vblank
->enabled
= false;
191 /* No further vblank irq's will be processed after
192 * this point. Get current hardware vblank count and
193 * vblank timestamp, repeat until they are consistent.
195 * FIXME: There is still a race condition here and in
196 * drm_update_vblank_count() which can cause off-by-one
197 * reinitialization of software vblank counter. If gpu
198 * vblank counter doesn't increment exactly at the leading
199 * edge of a vblank interval, then we can lose 1 count if
200 * we happen to execute between start of vblank and the
201 * delayed gpu counter increment.
204 vblank
->last
= dev
->driver
->get_vblank_counter(dev
, crtc
);
205 vblrc
= drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, 0);
206 } while (vblank
->last
!= dev
->driver
->get_vblank_counter(dev
, crtc
) && (--count
) && vblrc
);
211 /* Compute time difference to stored timestamp of last vblank
212 * as updated by last invocation of drm_handle_vblank() in vblank irq.
214 vblcount
= atomic_read(&vblank
->count
);
215 diff_ns
= timeval_to_ns(&tvblank
) -
216 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
218 /* If there is at least 1 msec difference between the last stored
219 * timestamp and tvblank, then we are currently executing our
220 * disable inside a new vblank interval, the tvblank timestamp
221 * corresponds to this new vblank interval and the irq handler
222 * for this vblank didn't run yet and won't run due to our disable.
223 * Therefore we need to do the job of drm_handle_vblank() and
224 * increment the vblank counter by one to account for this vblank.
226 * Skip this step if there isn't any high precision timestamp
227 * available. In that case we can't account for this and just
230 if (vblrc
&& (abs64(diff_ns
) > 1000000)) {
231 /* Store new timestamp in ringbuffer. */
232 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
234 /* Increment cooked vblank count. This also atomically commits
235 * the timestamp computed above.
237 smp_mb__before_atomic();
238 atomic_inc(&vblank
->count
);
239 smp_mb__after_atomic();
242 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
245 static void vblank_disable_fn(unsigned long arg
)
247 struct drm_vblank_crtc
*vblank
= (void *)arg
;
248 struct drm_device
*dev
= vblank
->dev
;
249 unsigned long irqflags
;
250 int crtc
= vblank
->crtc
;
252 if (!dev
->vblank_disable_allowed
)
255 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
256 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
257 DRM_DEBUG("disabling vblank on crtc %d\n", crtc
);
258 vblank_disable_and_save(dev
, crtc
);
260 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
264 * drm_vblank_cleanup - cleanup vblank support
267 * This function cleans up any resources allocated in drm_vblank_init.
269 void drm_vblank_cleanup(struct drm_device
*dev
)
272 unsigned long irqflags
;
274 /* Bail if the driver didn't call drm_vblank_init() */
275 if (dev
->num_crtcs
== 0)
278 for (crtc
= 0; crtc
< dev
->num_crtcs
; crtc
++) {
279 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
281 del_timer_sync(&vblank
->disable_timer
);
283 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
284 vblank_disable_and_save(dev
, crtc
);
285 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
292 EXPORT_SYMBOL(drm_vblank_cleanup
);
295 * drm_vblank_init - initialize vblank support
297 * @num_crtcs: number of crtcs supported by @dev
299 * This function initializes vblank support for @num_crtcs display pipelines.
302 * Zero on success or a negative error code on failure.
304 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
306 int i
, ret
= -ENOMEM
;
308 spin_lock_init(&dev
->vbl_lock
);
309 spin_lock_init(&dev
->vblank_time_lock
);
311 dev
->num_crtcs
= num_crtcs
;
313 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
317 for (i
= 0; i
< num_crtcs
; i
++) {
318 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
322 init_waitqueue_head(&vblank
->queue
);
323 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
324 (unsigned long)vblank
);
327 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
329 /* Driver specific high-precision vblank timestamping supported? */
330 if (dev
->driver
->get_vblank_timestamp
)
331 DRM_INFO("Driver supports precise vblank timestamp query.\n");
333 DRM_INFO("No driver support for vblank timestamp query.\n");
335 dev
->vblank_disable_allowed
= false;
343 EXPORT_SYMBOL(drm_vblank_init
);
345 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
347 struct drm_device
*dev
= cookie
;
349 if (dev
->driver
->vgaarb_irq
) {
350 dev
->driver
->vgaarb_irq(dev
, state
);
354 if (!dev
->irq_enabled
)
358 if (dev
->driver
->irq_uninstall
)
359 dev
->driver
->irq_uninstall(dev
);
361 if (dev
->driver
->irq_preinstall
)
362 dev
->driver
->irq_preinstall(dev
);
363 if (dev
->driver
->irq_postinstall
)
364 dev
->driver
->irq_postinstall(dev
);
369 * drm_irq_install - install IRQ handler
371 * @irq: IRQ number to install the handler for
373 * Initializes the IRQ related data. Installs the handler, calling the driver
374 * irq_preinstall() and irq_postinstall() functions before and after the
377 * This is the simplified helper interface provided for drivers with no special
378 * needs. Drivers which need to install interrupt handlers for multiple
379 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
380 * that vblank interrupts are available.
383 * Zero on success or a negative error code on failure.
385 int drm_irq_install(struct drm_device
*dev
, int irq
)
388 unsigned long sh_flags
= 0;
390 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
396 /* Driver must have been initialized */
397 if (!dev
->dev_private
)
400 if (dev
->irq_enabled
)
402 dev
->irq_enabled
= true;
404 DRM_DEBUG("irq=%d\n", irq
);
406 /* Before installing handler */
407 if (dev
->driver
->irq_preinstall
)
408 dev
->driver
->irq_preinstall(dev
);
410 /* Install handler */
411 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
412 sh_flags
= IRQF_SHARED
;
414 ret
= request_irq(irq
, dev
->driver
->irq_handler
,
415 sh_flags
, dev
->driver
->name
, dev
);
418 dev
->irq_enabled
= false;
422 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
423 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
425 /* After installing handler */
426 if (dev
->driver
->irq_postinstall
)
427 ret
= dev
->driver
->irq_postinstall(dev
);
430 dev
->irq_enabled
= false;
431 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
432 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
440 EXPORT_SYMBOL(drm_irq_install
);
443 * drm_irq_uninstall - uninstall the IRQ handler
446 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
447 * This should only be called by drivers which used drm_irq_install() to set up
448 * their interrupt handler. Other drivers must only reset
449 * drm_device->irq_enabled to false.
451 * Note that for kernel modesetting drivers it is a bug if this function fails.
452 * The sanity checks are only to catch buggy user modesetting drivers which call
453 * the same function through an ioctl.
456 * Zero on success or a negative error code on failure.
458 int drm_irq_uninstall(struct drm_device
*dev
)
460 unsigned long irqflags
;
464 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
467 irq_enabled
= dev
->irq_enabled
;
468 dev
->irq_enabled
= false;
471 * Wake up any waiters so they don't hang.
473 if (dev
->num_crtcs
) {
474 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
475 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
476 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
478 wake_up(&vblank
->queue
);
479 vblank
->enabled
= false;
481 dev
->driver
->get_vblank_counter(dev
, i
);
483 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
489 DRM_DEBUG("irq=%d\n", dev
->irq
);
491 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
492 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
494 if (dev
->driver
->irq_uninstall
)
495 dev
->driver
->irq_uninstall(dev
);
497 free_irq(dev
->irq
, dev
);
501 EXPORT_SYMBOL(drm_irq_uninstall
);
506 * \param inode device inode.
507 * \param file_priv DRM file private.
508 * \param cmd command.
509 * \param arg user argument, pointing to a drm_control structure.
510 * \return zero on success or a negative number on failure.
512 * Calls irq_install() or irq_uninstall() according to \p arg.
514 int drm_control(struct drm_device
*dev
, void *data
,
515 struct drm_file
*file_priv
)
517 struct drm_control
*ctl
= data
;
520 /* if we haven't irq we fallback for compatibility reasons -
521 * this used to be a separate function in drm_dma.h
524 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
526 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
528 /* UMS was only ever support on pci devices. */
529 if (WARN_ON(!dev
->pdev
))
533 case DRM_INST_HANDLER
:
534 irq
= dev
->pdev
->irq
;
536 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
539 mutex_lock(&dev
->struct_mutex
);
540 ret
= drm_irq_install(dev
, irq
);
541 mutex_unlock(&dev
->struct_mutex
);
544 case DRM_UNINST_HANDLER
:
545 mutex_lock(&dev
->struct_mutex
);
546 ret
= drm_irq_uninstall(dev
);
547 mutex_unlock(&dev
->struct_mutex
);
556 * drm_calc_timestamping_constants - calculate vblank timestamp constants
557 * @crtc: drm_crtc whose timestamp constants should be updated.
558 * @mode: display mode containing the scanout timings
560 * Calculate and store various constants which are later
561 * needed by vblank and swap-completion timestamping, e.g,
562 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
563 * derived from CRTC's true scanout timing, so they take
564 * things like panel scaling or other adjustments into account.
566 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
567 const struct drm_display_mode
*mode
)
569 int linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
570 int dotclock
= mode
->crtc_clock
;
572 /* Valid dotclock? */
574 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
577 * Convert scanline length in pixels and video
578 * dot clock to line duration, frame duration
579 * and pixel duration in nanoseconds:
581 pixeldur_ns
= 1000000 / dotclock
;
582 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
583 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
586 * Fields of interlaced scanout modes are only half a frame duration.
588 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
591 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
594 crtc
->pixeldur_ns
= pixeldur_ns
;
595 crtc
->linedur_ns
= linedur_ns
;
596 crtc
->framedur_ns
= framedur_ns
;
598 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
599 crtc
->base
.id
, mode
->crtc_htotal
,
600 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
601 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
602 crtc
->base
.id
, dotclock
, framedur_ns
,
603 linedur_ns
, pixeldur_ns
);
605 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
608 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
610 * @crtc: Which CRTC's vblank timestamp to retrieve
611 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
612 * On return contains true maximum error of timestamp
613 * @vblank_time: Pointer to struct timeval which should receive the timestamp
614 * @flags: Flags to pass to driver:
616 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
617 * @refcrtc: CRTC which defines scanout timing
618 * @mode: mode which defines the scanout timings
620 * Implements calculation of exact vblank timestamps from given drm_display_mode
621 * timings and current video scanout position of a CRTC. This can be called from
622 * within get_vblank_timestamp() implementation of a kms driver to implement the
623 * actual timestamping.
625 * Should return timestamps conforming to the OML_sync_control OpenML
626 * extension specification. The timestamp corresponds to the end of
627 * the vblank interval, aka start of scanout of topmost-leftmost display
628 * pixel in the following video frame.
630 * Requires support for optional dev->driver->get_scanout_position()
631 * in kms driver, plus a bit of setup code to provide a drm_display_mode
632 * that corresponds to the true scanout timing.
634 * The current implementation only handles standard video modes. It
635 * returns as no operation if a doublescan or interlaced video mode is
636 * active. Higher level code is expected to handle this.
639 * Negative value on error, failure or if not supported in current
642 * -EINVAL - Invalid CRTC.
643 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
644 * -ENOTSUPP - Function not supported in current display mode.
645 * -EIO - Failed, e.g., due to failed scanout position query.
647 * Returns or'ed positive status flags on success:
649 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
650 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
653 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
655 struct timeval
*vblank_time
,
657 const struct drm_crtc
*refcrtc
,
658 const struct drm_display_mode
*mode
)
660 struct timeval tv_etime
;
661 ktime_t stime
, etime
;
664 int framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
667 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
668 DRM_ERROR("Invalid crtc %d\n", crtc
);
672 /* Scanout position query not supported? Should not happen. */
673 if (!dev
->driver
->get_scanout_position
) {
674 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
678 /* Durations of frames, lines, pixels in nanoseconds. */
679 framedur_ns
= refcrtc
->framedur_ns
;
680 linedur_ns
= refcrtc
->linedur_ns
;
681 pixeldur_ns
= refcrtc
->pixeldur_ns
;
683 /* If mode timing undefined, just return as no-op:
684 * Happens during initial modesetting of a crtc.
686 if (framedur_ns
== 0) {
687 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
691 /* Get current scanout position with system timestamp.
692 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
693 * if single query takes longer than max_error nanoseconds.
695 * This guarantees a tight bound on maximum error if
696 * code gets preempted or delayed for some reason.
698 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
700 * Get vertical and horizontal scanout position vpos, hpos,
701 * and bounding timestamps stime, etime, pre/post query.
703 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, flags
, &vpos
,
704 &hpos
, &stime
, &etime
);
706 /* Return as no-op if scanout query unsupported or failed. */
707 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
708 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
713 /* Compute uncertainty in timestamp of scanout position query. */
714 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
716 /* Accept result with < max_error nsecs timing uncertainty. */
717 if (duration_ns
<= *max_error
)
721 /* Noisy system timing? */
722 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
723 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
724 crtc
, duration_ns
/1000, *max_error
/1000, i
);
727 /* Return upper bound of timestamp precision error. */
728 *max_error
= duration_ns
;
730 /* Check if in vblank area:
731 * vpos is >=0 in video scanout area, but negative
732 * within vblank area, counting down the number of lines until
735 invbl
= vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
;
737 /* Convert scanout position into elapsed time at raw_time query
738 * since start of scanout at first display scanline. delta_ns
739 * can be negative if start of scanout hasn't happened yet.
741 delta_ns
= vpos
* linedur_ns
+ hpos
* pixeldur_ns
;
743 if (!drm_timestamp_monotonic
)
744 etime
= ktime_mono_to_real(etime
);
746 /* save this only for debugging purposes */
747 tv_etime
= ktime_to_timeval(etime
);
748 /* Subtract time delta from raw timestamp to get final
749 * vblank_time timestamp for end of vblank.
752 etime
= ktime_add_ns(etime
, -delta_ns
);
754 etime
= ktime_sub_ns(etime
, delta_ns
);
755 *vblank_time
= ktime_to_timeval(etime
);
757 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
758 crtc
, (int)vbl_status
, hpos
, vpos
,
759 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
760 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
761 duration_ns
/1000, i
);
763 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
765 vbl_status
|= DRM_VBLANKTIME_IN_VBLANK
;
769 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
771 static struct timeval
get_drm_timestamp(void)
775 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
776 return ktime_to_timeval(now
);
780 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
783 * @crtc: which CRTC's vblank timestamp to retrieve
784 * @tvblank: Pointer to target struct timeval which should receive the timestamp
785 * @flags: Flags to pass to driver:
787 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
789 * Fetches the system timestamp corresponding to the time of the most recent
790 * vblank interval on specified CRTC. May call into kms-driver to
791 * compute the timestamp with a high-precision GPU specific method.
793 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
794 * call, i.e., it isn't very precisely locked to the true vblank.
797 * True if timestamp is considered to be very precise, false otherwise.
800 drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
801 struct timeval
*tvblank
, unsigned flags
)
805 /* Define requested maximum error on timestamps (nanoseconds). */
806 int max_error
= (int) drm_timestamp_precision
* 1000;
808 /* Query driver if possible and precision timestamping enabled. */
809 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
810 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
816 /* GPU high precision timestamp query unsupported or failed.
817 * Return current monotonic/gettimeofday timestamp as best estimate.
819 *tvblank
= get_drm_timestamp();
825 * drm_vblank_count - retrieve "cooked" vblank counter value
827 * @crtc: which counter to retrieve
829 * Fetches the "cooked" vblank count value that represents the number of
830 * vblank events since the system was booted, including lost events due to
831 * modesetting activity.
834 * The software vblank counter.
836 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
838 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
840 if (WARN_ON(crtc
>= dev
->num_crtcs
))
842 return atomic_read(&vblank
->count
);
844 EXPORT_SYMBOL(drm_vblank_count
);
847 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
848 * and the system timestamp corresponding to that vblank counter value.
851 * @crtc: which counter to retrieve
852 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
854 * Fetches the "cooked" vblank count value that represents the number of
855 * vblank events since the system was booted, including lost events due to
856 * modesetting activity. Returns corresponding system timestamp of the time
857 * of the vblank interval that corresponds to the current vblank counter value.
859 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
860 struct timeval
*vblanktime
)
862 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
865 if (WARN_ON(crtc
>= dev
->num_crtcs
))
868 /* Read timestamp from slot of _vblank_time ringbuffer
869 * that corresponds to current vblank count. Retry if
870 * count has incremented during readout. This works like
874 cur_vblank
= atomic_read(&vblank
->count
);
875 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
877 } while (cur_vblank
!= atomic_read(&vblank
->count
));
881 EXPORT_SYMBOL(drm_vblank_count_and_time
);
883 static void send_vblank_event(struct drm_device
*dev
,
884 struct drm_pending_vblank_event
*e
,
885 unsigned long seq
, struct timeval
*now
)
887 WARN_ON_SMP(!spin_is_locked(&dev
->event_lock
));
888 e
->event
.sequence
= seq
;
889 e
->event
.tv_sec
= now
->tv_sec
;
890 e
->event
.tv_usec
= now
->tv_usec
;
892 list_add_tail(&e
->base
.link
,
893 &e
->base
.file_priv
->event_list
);
894 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
895 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
900 * drm_send_vblank_event - helper to send vblank event after pageflip
902 * @crtc: CRTC in question
903 * @e: the event to send
905 * Updates sequence # and timestamp on event, and sends it to userspace.
906 * Caller must hold event lock.
908 void drm_send_vblank_event(struct drm_device
*dev
, int crtc
,
909 struct drm_pending_vblank_event
*e
)
914 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
918 now
= get_drm_timestamp();
921 send_vblank_event(dev
, e
, seq
, &now
);
923 EXPORT_SYMBOL(drm_send_vblank_event
);
926 * drm_vblank_enable - enable the vblank interrupt on a CRTC
928 * @crtc: CRTC in question
930 static int drm_vblank_enable(struct drm_device
*dev
, int crtc
)
932 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
935 assert_spin_locked(&dev
->vbl_lock
);
937 spin_lock(&dev
->vblank_time_lock
);
939 if (!vblank
->enabled
) {
941 * Enable vblank irqs under vblank_time_lock protection.
942 * All vblank count & timestamp updates are held off
943 * until we are done reinitializing master counter and
944 * timestamps. Filtercode in drm_handle_vblank() will
945 * prevent double-accounting of same vblank interval.
947 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
948 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc
, ret
);
950 atomic_dec(&vblank
->refcount
);
952 vblank
->enabled
= true;
953 drm_update_vblank_count(dev
, crtc
);
957 spin_unlock(&dev
->vblank_time_lock
);
963 * drm_vblank_get - get a reference count on vblank events
965 * @crtc: which CRTC to own
967 * Acquire a reference count on vblank events to avoid having them disabled
970 * This is the legacy version of drm_crtc_vblank_get().
973 * Zero on success, nonzero on failure.
975 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
977 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
978 unsigned long irqflags
;
981 if (WARN_ON(crtc
>= dev
->num_crtcs
))
984 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
985 /* Going from 0->1 means we have to enable interrupts again */
986 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
987 ret
= drm_vblank_enable(dev
, crtc
);
989 if (!vblank
->enabled
) {
990 atomic_dec(&vblank
->refcount
);
994 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
998 EXPORT_SYMBOL(drm_vblank_get
);
1001 * drm_crtc_vblank_get - get a reference count on vblank events
1002 * @crtc: which CRTC to own
1004 * Acquire a reference count on vblank events to avoid having them disabled
1007 * This is the native kms version of drm_vblank_off().
1010 * Zero on success, nonzero on failure.
1012 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1014 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1016 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1019 * drm_vblank_put - give up ownership of vblank events
1021 * @crtc: which counter to give up
1023 * Release ownership of a given vblank counter, turning off interrupts
1024 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1026 * This is the legacy version of drm_crtc_vblank_put().
1028 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
1030 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1032 BUG_ON(atomic_read(&vblank
->refcount
) == 0);
1034 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1037 /* Last user schedules interrupt disable */
1038 if (atomic_dec_and_test(&vblank
->refcount
)) {
1039 if (drm_vblank_offdelay
== 0)
1041 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1042 vblank_disable_fn((unsigned long)vblank
);
1044 mod_timer(&vblank
->disable_timer
,
1045 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1048 EXPORT_SYMBOL(drm_vblank_put
);
1051 * drm_crtc_vblank_put - give up ownership of vblank events
1052 * @crtc: which counter to give up
1054 * Release ownership of a given vblank counter, turning off interrupts
1055 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1057 * This is the native kms version of drm_vblank_put().
1059 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1061 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1063 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1066 * drm_wait_one_vblank - wait for one vblank
1070 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1071 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1072 * due to lack of driver support or because the crtc is off.
1074 void drm_wait_one_vblank(struct drm_device
*dev
, int crtc
)
1079 ret
= drm_vblank_get(dev
, crtc
);
1080 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", crtc
, ret
))
1083 last
= drm_vblank_count(dev
, crtc
);
1085 ret
= wait_event_timeout(dev
->vblank
[crtc
].queue
,
1086 last
!= drm_vblank_count(dev
, crtc
),
1087 msecs_to_jiffies(100));
1089 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", crtc
);
1091 drm_vblank_put(dev
, crtc
);
1093 EXPORT_SYMBOL(drm_wait_one_vblank
);
1096 * drm_crtc_wait_one_vblank - wait for one vblank
1099 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1100 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1101 * due to lack of driver support or because the crtc is off.
1103 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1105 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1107 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1110 * drm_vblank_off - disable vblank events on a CRTC
1112 * @crtc: CRTC in question
1114 * Drivers can use this function to shut down the vblank interrupt handling when
1115 * disabling a crtc. This function ensures that the latest vblank frame count is
1116 * stored so that drm_vblank_on() can restore it again.
1118 * Drivers must use this function when the hardware vblank counter can get
1119 * reset, e.g. when suspending.
1121 * This is the legacy version of drm_crtc_vblank_off().
1123 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
1125 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1126 struct drm_pending_vblank_event
*e
, *t
;
1128 unsigned long irqflags
;
1131 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1134 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1136 spin_lock(&dev
->vbl_lock
);
1137 vblank_disable_and_save(dev
, crtc
);
1138 wake_up(&vblank
->queue
);
1141 * Prevent subsequent drm_vblank_get() from re-enabling
1142 * the vblank interrupt by bumping the refcount.
1144 if (!vblank
->inmodeset
) {
1145 atomic_inc(&vblank
->refcount
);
1146 vblank
->inmodeset
= 1;
1148 spin_unlock(&dev
->vbl_lock
);
1150 /* Send any queued vblank events, lest the natives grow disquiet */
1151 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1153 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1154 if (e
->pipe
!= crtc
)
1156 DRM_DEBUG("Sending premature vblank event on disable: \
1157 wanted %d, current %d\n",
1158 e
->event
.sequence
, seq
);
1159 list_del(&e
->base
.link
);
1160 drm_vblank_put(dev
, e
->pipe
);
1161 send_vblank_event(dev
, e
, seq
, &now
);
1163 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1165 EXPORT_SYMBOL(drm_vblank_off
);
1168 * drm_crtc_vblank_off - disable vblank events on a CRTC
1169 * @crtc: CRTC in question
1171 * Drivers can use this function to shut down the vblank interrupt handling when
1172 * disabling a crtc. This function ensures that the latest vblank frame count is
1173 * stored so that drm_vblank_on can restore it again.
1175 * Drivers must use this function when the hardware vblank counter can get
1176 * reset, e.g. when suspending.
1178 * This is the native kms version of drm_vblank_off().
1180 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1182 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1184 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1187 * drm_vblank_on - enable vblank events on a CRTC
1189 * @crtc: CRTC in question
1191 * This functions restores the vblank interrupt state captured with
1192 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1193 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1194 * in driver load code to reflect the current hardware state of the crtc.
1196 * This is the legacy version of drm_crtc_vblank_on().
1198 void drm_vblank_on(struct drm_device
*dev
, int crtc
)
1200 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1201 unsigned long irqflags
;
1203 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1206 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1207 /* Drop our private "prevent drm_vblank_get" refcount */
1208 if (vblank
->inmodeset
) {
1209 atomic_dec(&vblank
->refcount
);
1210 vblank
->inmodeset
= 0;
1214 * sample the current counter to avoid random jumps
1215 * when drm_vblank_enable() applies the diff
1217 * -1 to make sure user will never see the same
1218 * vblank counter value before and after a modeset
1221 (dev
->driver
->get_vblank_counter(dev
, crtc
) - 1) &
1222 dev
->max_vblank_count
;
1224 * re-enable interrupts if there are users left, or the
1225 * user wishes vblank interrupts to be enabled all the time.
1227 if (atomic_read(&vblank
->refcount
) != 0 ||
1228 (!dev
->vblank_disable_immediate
&& drm_vblank_offdelay
== 0))
1229 WARN_ON(drm_vblank_enable(dev
, crtc
));
1230 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1232 EXPORT_SYMBOL(drm_vblank_on
);
1235 * drm_crtc_vblank_on - enable vblank events on a CRTC
1236 * @crtc: CRTC in question
1238 * This functions restores the vblank interrupt state captured with
1239 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1240 * drm_vblank_off() can be unbalanced and so can also be unconditionaly called
1241 * in driver load code to reflect the current hardware state of the crtc.
1243 * This is the native kms version of drm_vblank_on().
1245 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1247 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1249 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1252 * drm_vblank_pre_modeset - account for vblanks across mode sets
1254 * @crtc: CRTC in question
1256 * Account for vblank events across mode setting events, which will likely
1257 * reset the hardware frame counter.
1259 * This is done by grabbing a temporary vblank reference to ensure that the
1260 * vblank interrupt keeps running across the modeset sequence. With this the
1261 * software-side vblank frame counting will ensure that there are no jumps or
1264 * Unfortunately this approach is racy and also doesn't work when the vblank
1265 * interrupt stops running, e.g. across system suspend resume. It is therefore
1266 * highly recommended that drivers use the newer drm_vblank_off() and
1267 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1268 * using "cooked" software vblank frame counters and not relying on any hardware
1271 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1274 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
1276 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1278 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1279 if (!dev
->num_crtcs
)
1282 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1286 * To avoid all the problems that might happen if interrupts
1287 * were enabled/disabled around or between these calls, we just
1288 * have the kernel take a reference on the CRTC (just once though
1289 * to avoid corrupting the count if multiple, mismatch calls occur),
1290 * so that interrupts remain enabled in the interim.
1292 if (!vblank
->inmodeset
) {
1293 vblank
->inmodeset
= 0x1;
1294 if (drm_vblank_get(dev
, crtc
) == 0)
1295 vblank
->inmodeset
|= 0x2;
1298 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1301 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1303 * @crtc: CRTC in question
1305 * This function again drops the temporary vblank reference acquired in
1306 * drm_vblank_pre_modeset.
1308 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
1310 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1311 unsigned long irqflags
;
1313 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1314 if (!dev
->num_crtcs
)
1317 if (vblank
->inmodeset
) {
1318 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1319 dev
->vblank_disable_allowed
= true;
1320 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1322 if (vblank
->inmodeset
& 0x2)
1323 drm_vblank_put(dev
, crtc
);
1325 vblank
->inmodeset
= 0;
1328 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1331 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1332 * @DRM_IOCTL_ARGS: standard ioctl arguments
1334 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1335 * ioctls around modesetting so that any lost vblank events are accounted for.
1337 * Generally the counter will reset across mode sets. If interrupts are
1338 * enabled around this call, we don't have to do anything since the counter
1339 * will have already been incremented.
1341 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1342 struct drm_file
*file_priv
)
1344 struct drm_modeset_ctl
*modeset
= data
;
1347 /* If drm_vblank_init() hasn't been called yet, just no-op */
1348 if (!dev
->num_crtcs
)
1351 /* KMS drivers handle this internally */
1352 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1355 crtc
= modeset
->crtc
;
1356 if (crtc
>= dev
->num_crtcs
)
1359 switch (modeset
->cmd
) {
1360 case _DRM_PRE_MODESET
:
1361 drm_vblank_pre_modeset(dev
, crtc
);
1363 case _DRM_POST_MODESET
:
1364 drm_vblank_post_modeset(dev
, crtc
);
1373 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1374 union drm_wait_vblank
*vblwait
,
1375 struct drm_file
*file_priv
)
1377 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1378 struct drm_pending_vblank_event
*e
;
1380 unsigned long flags
;
1384 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1391 e
->base
.pid
= current
->pid
;
1392 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1393 e
->event
.base
.length
= sizeof e
->event
;
1394 e
->event
.user_data
= vblwait
->request
.signal
;
1395 e
->base
.event
= &e
->event
.base
;
1396 e
->base
.file_priv
= file_priv
;
1397 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1399 spin_lock_irqsave(&dev
->event_lock
, flags
);
1402 * drm_vblank_off() might have been called after we called
1403 * drm_vblank_get(). drm_vblank_off() holds event_lock
1404 * around the vblank disable, so no need for further locking.
1405 * The reference from drm_vblank_get() protects against
1406 * vblank disable from another source.
1408 if (!vblank
->enabled
) {
1413 if (file_priv
->event_space
< sizeof e
->event
) {
1418 file_priv
->event_space
-= sizeof e
->event
;
1419 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1421 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1422 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1423 vblwait
->request
.sequence
= seq
+ 1;
1424 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1427 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1428 vblwait
->request
.sequence
, seq
, pipe
);
1430 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1431 vblwait
->request
.sequence
);
1433 e
->event
.sequence
= vblwait
->request
.sequence
;
1434 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1435 drm_vblank_put(dev
, pipe
);
1436 send_vblank_event(dev
, e
, seq
, &now
);
1437 vblwait
->reply
.sequence
= seq
;
1439 /* drm_handle_vblank_events will call drm_vblank_put */
1440 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1441 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1444 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1449 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1452 drm_vblank_put(dev
, pipe
);
1459 * \param inode device inode.
1460 * \param file_priv DRM file private.
1461 * \param cmd command.
1462 * \param data user argument, pointing to a drm_wait_vblank structure.
1463 * \return zero on success or a negative number on failure.
1465 * This function enables the vblank interrupt on the pipe requested, then
1466 * sleeps waiting for the requested sequence number to occur, and drops
1467 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1468 * after a timeout with no further vblank waits scheduled).
1470 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1471 struct drm_file
*file_priv
)
1473 struct drm_vblank_crtc
*vblank
;
1474 union drm_wait_vblank
*vblwait
= data
;
1476 unsigned int flags
, seq
, crtc
, high_crtc
;
1478 if (!dev
->irq_enabled
)
1481 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1484 if (vblwait
->request
.type
&
1485 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1486 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1487 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1488 vblwait
->request
.type
,
1489 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1490 _DRM_VBLANK_HIGH_CRTC_MASK
));
1494 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1495 high_crtc
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1497 crtc
= high_crtc
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1499 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1500 if (crtc
>= dev
->num_crtcs
)
1503 vblank
= &dev
->vblank
[crtc
];
1505 ret
= drm_vblank_get(dev
, crtc
);
1507 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1510 seq
= drm_vblank_count(dev
, crtc
);
1512 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1513 case _DRM_VBLANK_RELATIVE
:
1514 vblwait
->request
.sequence
+= seq
;
1515 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1516 case _DRM_VBLANK_ABSOLUTE
:
1523 if (flags
& _DRM_VBLANK_EVENT
) {
1524 /* must hold on to the vblank ref until the event fires
1525 * drm_vblank_put will be called asynchronously
1527 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1530 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1531 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1532 vblwait
->request
.sequence
= seq
+ 1;
1535 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1536 vblwait
->request
.sequence
, crtc
);
1537 vblank
->last_wait
= vblwait
->request
.sequence
;
1538 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1539 (((drm_vblank_count(dev
, crtc
) -
1540 vblwait
->request
.sequence
) <= (1 << 23)) ||
1542 !dev
->irq_enabled
));
1544 if (ret
!= -EINTR
) {
1547 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1548 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1549 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1551 DRM_DEBUG("returning %d to client\n",
1552 vblwait
->reply
.sequence
);
1554 DRM_DEBUG("vblank wait interrupted by signal\n");
1558 drm_vblank_put(dev
, crtc
);
1562 static void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1564 struct drm_pending_vblank_event
*e
, *t
;
1568 assert_spin_locked(&dev
->event_lock
);
1570 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1572 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1573 if (e
->pipe
!= crtc
)
1575 if ((seq
- e
->event
.sequence
) > (1<<23))
1578 DRM_DEBUG("vblank event on %d, current %d\n",
1579 e
->event
.sequence
, seq
);
1581 list_del(&e
->base
.link
);
1582 drm_vblank_put(dev
, e
->pipe
);
1583 send_vblank_event(dev
, e
, seq
, &now
);
1586 trace_drm_vblank_event(crtc
, seq
);
1590 * drm_handle_vblank - handle a vblank event
1592 * @crtc: where this event occurred
1594 * Drivers should call this routine in their vblank interrupt handlers to
1595 * update the vblank counter and send any signals that may be pending.
1597 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1599 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1602 struct timeval tvblank
;
1603 unsigned long irqflags
;
1605 if (!dev
->num_crtcs
)
1608 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1611 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1613 /* Need timestamp lock to prevent concurrent execution with
1614 * vblank enable/disable, as this would cause inconsistent
1615 * or corrupted timestamps and vblank counts.
1617 spin_lock(&dev
->vblank_time_lock
);
1619 /* Vblank irq handling disabled. Nothing to do. */
1620 if (!vblank
->enabled
) {
1621 spin_unlock(&dev
->vblank_time_lock
);
1622 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1626 /* Fetch corresponding timestamp for this vblank interval from
1627 * driver and store it in proper slot of timestamp ringbuffer.
1630 /* Get current timestamp and count. */
1631 vblcount
= atomic_read(&vblank
->count
);
1632 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1634 /* Compute time difference to timestamp of last vblank */
1635 diff_ns
= timeval_to_ns(&tvblank
) -
1636 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1638 /* Update vblank timestamp and count if at least
1639 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1640 * difference between last stored timestamp and current
1641 * timestamp. A smaller difference means basically
1642 * identical timestamps. Happens if this vblank has
1643 * been already processed and this is a redundant call,
1644 * e.g., due to spurious vblank interrupts. We need to
1645 * ignore those for accounting.
1647 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1648 /* Store new timestamp in ringbuffer. */
1649 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1651 /* Increment cooked vblank count. This also atomically commits
1652 * the timestamp computed above.
1654 smp_mb__before_atomic();
1655 atomic_inc(&vblank
->count
);
1656 smp_mb__after_atomic();
1658 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1659 crtc
, (int) diff_ns
);
1662 spin_unlock(&dev
->vblank_time_lock
);
1664 wake_up(&vblank
->queue
);
1665 drm_handle_vblank_events(dev
, crtc
);
1667 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1671 EXPORT_SYMBOL(drm_handle_vblank
);