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 disabled 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.
833 * This is the legacy version of drm_crtc_vblank_count().
836 * The software vblank counter.
838 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
840 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
842 if (WARN_ON(crtc
>= dev
->num_crtcs
))
844 return atomic_read(&vblank
->count
);
846 EXPORT_SYMBOL(drm_vblank_count
);
849 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
850 * @crtc: which counter to retrieve
852 * Fetches the "cooked" vblank count value that represents the number of
853 * vblank events since the system was booted, including lost events due to
854 * modesetting activity.
856 * This is the native KMS version of drm_vblank_count().
859 * The software vblank counter.
861 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
863 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
865 EXPORT_SYMBOL(drm_crtc_vblank_count
);
868 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
869 * and the system timestamp corresponding to that vblank counter value.
872 * @crtc: which counter to retrieve
873 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
875 * Fetches the "cooked" vblank count value that represents the number of
876 * vblank events since the system was booted, including lost events due to
877 * modesetting activity. Returns corresponding system timestamp of the time
878 * of the vblank interval that corresponds to the current vblank counter value.
880 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
881 struct timeval
*vblanktime
)
883 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
886 if (WARN_ON(crtc
>= dev
->num_crtcs
))
889 /* Read timestamp from slot of _vblank_time ringbuffer
890 * that corresponds to current vblank count. Retry if
891 * count has incremented during readout. This works like
895 cur_vblank
= atomic_read(&vblank
->count
);
896 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
898 } while (cur_vblank
!= atomic_read(&vblank
->count
));
902 EXPORT_SYMBOL(drm_vblank_count_and_time
);
904 static void send_vblank_event(struct drm_device
*dev
,
905 struct drm_pending_vblank_event
*e
,
906 unsigned long seq
, struct timeval
*now
)
908 WARN_ON_SMP(!spin_is_locked(&dev
->event_lock
));
909 e
->event
.sequence
= seq
;
910 e
->event
.tv_sec
= now
->tv_sec
;
911 e
->event
.tv_usec
= now
->tv_usec
;
913 list_add_tail(&e
->base
.link
,
914 &e
->base
.file_priv
->event_list
);
915 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
916 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
921 * drm_send_vblank_event - helper to send vblank event after pageflip
923 * @crtc: CRTC in question
924 * @e: the event to send
926 * Updates sequence # and timestamp on event, and sends it to userspace.
927 * Caller must hold event lock.
929 * This is the legacy version of drm_crtc_send_vblank_event().
931 void drm_send_vblank_event(struct drm_device
*dev
, int crtc
,
932 struct drm_pending_vblank_event
*e
)
937 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
941 now
= get_drm_timestamp();
944 send_vblank_event(dev
, e
, seq
, &now
);
946 EXPORT_SYMBOL(drm_send_vblank_event
);
949 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
950 * @crtc: the source CRTC of the vblank event
951 * @e: the event to send
953 * Updates sequence # and timestamp on event, and sends it to userspace.
954 * Caller must hold event lock.
956 * This is the native KMS version of drm_send_vblank_event().
958 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
959 struct drm_pending_vblank_event
*e
)
961 drm_send_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
963 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
966 * drm_vblank_enable - enable the vblank interrupt on a CRTC
968 * @crtc: CRTC in question
970 static int drm_vblank_enable(struct drm_device
*dev
, int crtc
)
972 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
975 assert_spin_locked(&dev
->vbl_lock
);
977 spin_lock(&dev
->vblank_time_lock
);
979 if (!vblank
->enabled
) {
981 * Enable vblank irqs under vblank_time_lock protection.
982 * All vblank count & timestamp updates are held off
983 * until we are done reinitializing master counter and
984 * timestamps. Filtercode in drm_handle_vblank() will
985 * prevent double-accounting of same vblank interval.
987 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
988 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", crtc
, ret
);
990 atomic_dec(&vblank
->refcount
);
992 vblank
->enabled
= true;
993 drm_update_vblank_count(dev
, crtc
);
997 spin_unlock(&dev
->vblank_time_lock
);
1003 * drm_vblank_get - get a reference count on vblank events
1005 * @crtc: which CRTC to own
1007 * Acquire a reference count on vblank events to avoid having them disabled
1010 * This is the legacy version of drm_crtc_vblank_get().
1013 * Zero on success, nonzero on failure.
1015 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
1017 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1018 unsigned long irqflags
;
1021 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1024 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1025 /* Going from 0->1 means we have to enable interrupts again */
1026 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1027 ret
= drm_vblank_enable(dev
, crtc
);
1029 if (!vblank
->enabled
) {
1030 atomic_dec(&vblank
->refcount
);
1034 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1038 EXPORT_SYMBOL(drm_vblank_get
);
1041 * drm_crtc_vblank_get - get a reference count on vblank events
1042 * @crtc: which CRTC to own
1044 * Acquire a reference count on vblank events to avoid having them disabled
1047 * This is the native kms version of drm_vblank_off().
1050 * Zero on success, nonzero on failure.
1052 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1054 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1056 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1059 * drm_vblank_put - give up ownership of vblank events
1061 * @crtc: which counter to give up
1063 * Release ownership of a given vblank counter, turning off interrupts
1064 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1066 * This is the legacy version of drm_crtc_vblank_put().
1068 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
1070 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1072 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1075 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1078 /* Last user schedules interrupt disable */
1079 if (atomic_dec_and_test(&vblank
->refcount
)) {
1080 if (drm_vblank_offdelay
== 0)
1082 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1083 vblank_disable_fn((unsigned long)vblank
);
1085 mod_timer(&vblank
->disable_timer
,
1086 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1089 EXPORT_SYMBOL(drm_vblank_put
);
1092 * drm_crtc_vblank_put - give up ownership of vblank events
1093 * @crtc: which counter to give up
1095 * Release ownership of a given vblank counter, turning off interrupts
1096 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1098 * This is the native kms version of drm_vblank_put().
1100 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1102 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1104 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1107 * drm_wait_one_vblank - wait for one vblank
1111 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1112 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1113 * due to lack of driver support or because the crtc is off.
1115 void drm_wait_one_vblank(struct drm_device
*dev
, int crtc
)
1120 ret
= drm_vblank_get(dev
, crtc
);
1121 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", crtc
, ret
))
1124 last
= drm_vblank_count(dev
, crtc
);
1126 ret
= wait_event_timeout(dev
->vblank
[crtc
].queue
,
1127 last
!= drm_vblank_count(dev
, crtc
),
1128 msecs_to_jiffies(100));
1130 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", crtc
);
1132 drm_vblank_put(dev
, crtc
);
1134 EXPORT_SYMBOL(drm_wait_one_vblank
);
1137 * drm_crtc_wait_one_vblank - wait for one vblank
1140 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1141 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1142 * due to lack of driver support or because the crtc is off.
1144 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1146 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1148 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1151 * drm_vblank_off - disable vblank events on a CRTC
1153 * @crtc: CRTC in question
1155 * Drivers can use this function to shut down the vblank interrupt handling when
1156 * disabling a crtc. This function ensures that the latest vblank frame count is
1157 * stored so that drm_vblank_on() can restore it again.
1159 * Drivers must use this function when the hardware vblank counter can get
1160 * reset, e.g. when suspending.
1162 * This is the legacy version of drm_crtc_vblank_off().
1164 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
1166 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1167 struct drm_pending_vblank_event
*e
, *t
;
1169 unsigned long irqflags
;
1172 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1175 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1177 spin_lock(&dev
->vbl_lock
);
1178 vblank_disable_and_save(dev
, crtc
);
1179 wake_up(&vblank
->queue
);
1182 * Prevent subsequent drm_vblank_get() from re-enabling
1183 * the vblank interrupt by bumping the refcount.
1185 if (!vblank
->inmodeset
) {
1186 atomic_inc(&vblank
->refcount
);
1187 vblank
->inmodeset
= 1;
1189 spin_unlock(&dev
->vbl_lock
);
1191 /* Send any queued vblank events, lest the natives grow disquiet */
1192 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1194 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1195 if (e
->pipe
!= crtc
)
1197 DRM_DEBUG("Sending premature vblank event on disable: \
1198 wanted %d, current %d\n",
1199 e
->event
.sequence
, seq
);
1200 list_del(&e
->base
.link
);
1201 drm_vblank_put(dev
, e
->pipe
);
1202 send_vblank_event(dev
, e
, seq
, &now
);
1204 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1206 EXPORT_SYMBOL(drm_vblank_off
);
1209 * drm_crtc_vblank_off - disable vblank events on a CRTC
1210 * @crtc: CRTC in question
1212 * Drivers can use this function to shut down the vblank interrupt handling when
1213 * disabling a crtc. This function ensures that the latest vblank frame count is
1214 * stored so that drm_vblank_on can restore it again.
1216 * Drivers must use this function when the hardware vblank counter can get
1217 * reset, e.g. when suspending.
1219 * This is the native kms version of drm_vblank_off().
1221 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1223 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1225 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1228 * drm_vblank_on - enable vblank events on a CRTC
1230 * @crtc: CRTC in question
1232 * This functions restores the vblank interrupt state captured with
1233 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1234 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1235 * in driver load code to reflect the current hardware state of the crtc.
1237 * This is the legacy version of drm_crtc_vblank_on().
1239 void drm_vblank_on(struct drm_device
*dev
, int crtc
)
1241 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1242 unsigned long irqflags
;
1244 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1247 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1248 /* Drop our private "prevent drm_vblank_get" refcount */
1249 if (vblank
->inmodeset
) {
1250 atomic_dec(&vblank
->refcount
);
1251 vblank
->inmodeset
= 0;
1255 * sample the current counter to avoid random jumps
1256 * when drm_vblank_enable() applies the diff
1258 * -1 to make sure user will never see the same
1259 * vblank counter value before and after a modeset
1262 (dev
->driver
->get_vblank_counter(dev
, crtc
) - 1) &
1263 dev
->max_vblank_count
;
1265 * re-enable interrupts if there are users left, or the
1266 * user wishes vblank interrupts to be enabled all the time.
1268 if (atomic_read(&vblank
->refcount
) != 0 ||
1269 (!dev
->vblank_disable_immediate
&& drm_vblank_offdelay
== 0))
1270 WARN_ON(drm_vblank_enable(dev
, crtc
));
1271 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1273 EXPORT_SYMBOL(drm_vblank_on
);
1276 * drm_crtc_vblank_on - enable vblank events on a CRTC
1277 * @crtc: CRTC in question
1279 * This functions restores the vblank interrupt state captured with
1280 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1281 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1282 * in driver load code to reflect the current hardware state of the crtc.
1284 * This is the native kms version of drm_vblank_on().
1286 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1288 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1290 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1293 * drm_vblank_pre_modeset - account for vblanks across mode sets
1295 * @crtc: CRTC in question
1297 * Account for vblank events across mode setting events, which will likely
1298 * reset the hardware frame counter.
1300 * This is done by grabbing a temporary vblank reference to ensure that the
1301 * vblank interrupt keeps running across the modeset sequence. With this the
1302 * software-side vblank frame counting will ensure that there are no jumps or
1305 * Unfortunately this approach is racy and also doesn't work when the vblank
1306 * interrupt stops running, e.g. across system suspend resume. It is therefore
1307 * highly recommended that drivers use the newer drm_vblank_off() and
1308 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1309 * using "cooked" software vblank frame counters and not relying on any hardware
1312 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1315 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
1317 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1319 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1320 if (!dev
->num_crtcs
)
1323 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1327 * To avoid all the problems that might happen if interrupts
1328 * were enabled/disabled around or between these calls, we just
1329 * have the kernel take a reference on the CRTC (just once though
1330 * to avoid corrupting the count if multiple, mismatch calls occur),
1331 * so that interrupts remain enabled in the interim.
1333 if (!vblank
->inmodeset
) {
1334 vblank
->inmodeset
= 0x1;
1335 if (drm_vblank_get(dev
, crtc
) == 0)
1336 vblank
->inmodeset
|= 0x2;
1339 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1342 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1344 * @crtc: CRTC in question
1346 * This function again drops the temporary vblank reference acquired in
1347 * drm_vblank_pre_modeset.
1349 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
1351 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1352 unsigned long irqflags
;
1354 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1355 if (!dev
->num_crtcs
)
1358 if (vblank
->inmodeset
) {
1359 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1360 dev
->vblank_disable_allowed
= true;
1361 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1363 if (vblank
->inmodeset
& 0x2)
1364 drm_vblank_put(dev
, crtc
);
1366 vblank
->inmodeset
= 0;
1369 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1372 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1373 * @DRM_IOCTL_ARGS: standard ioctl arguments
1375 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1376 * ioctls around modesetting so that any lost vblank events are accounted for.
1378 * Generally the counter will reset across mode sets. If interrupts are
1379 * enabled around this call, we don't have to do anything since the counter
1380 * will have already been incremented.
1382 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1383 struct drm_file
*file_priv
)
1385 struct drm_modeset_ctl
*modeset
= data
;
1388 /* If drm_vblank_init() hasn't been called yet, just no-op */
1389 if (!dev
->num_crtcs
)
1392 /* KMS drivers handle this internally */
1393 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1396 crtc
= modeset
->crtc
;
1397 if (crtc
>= dev
->num_crtcs
)
1400 switch (modeset
->cmd
) {
1401 case _DRM_PRE_MODESET
:
1402 drm_vblank_pre_modeset(dev
, crtc
);
1404 case _DRM_POST_MODESET
:
1405 drm_vblank_post_modeset(dev
, crtc
);
1414 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1415 union drm_wait_vblank
*vblwait
,
1416 struct drm_file
*file_priv
)
1418 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1419 struct drm_pending_vblank_event
*e
;
1421 unsigned long flags
;
1425 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1432 e
->base
.pid
= current
->pid
;
1433 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1434 e
->event
.base
.length
= sizeof e
->event
;
1435 e
->event
.user_data
= vblwait
->request
.signal
;
1436 e
->base
.event
= &e
->event
.base
;
1437 e
->base
.file_priv
= file_priv
;
1438 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1440 spin_lock_irqsave(&dev
->event_lock
, flags
);
1443 * drm_vblank_off() might have been called after we called
1444 * drm_vblank_get(). drm_vblank_off() holds event_lock
1445 * around the vblank disable, so no need for further locking.
1446 * The reference from drm_vblank_get() protects against
1447 * vblank disable from another source.
1449 if (!vblank
->enabled
) {
1454 if (file_priv
->event_space
< sizeof e
->event
) {
1459 file_priv
->event_space
-= sizeof e
->event
;
1460 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1462 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1463 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1464 vblwait
->request
.sequence
= seq
+ 1;
1465 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1468 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1469 vblwait
->request
.sequence
, seq
, pipe
);
1471 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1472 vblwait
->request
.sequence
);
1474 e
->event
.sequence
= vblwait
->request
.sequence
;
1475 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1476 drm_vblank_put(dev
, pipe
);
1477 send_vblank_event(dev
, e
, seq
, &now
);
1478 vblwait
->reply
.sequence
= seq
;
1480 /* drm_handle_vblank_events will call drm_vblank_put */
1481 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1482 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1485 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1490 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1493 drm_vblank_put(dev
, pipe
);
1500 * \param inode device inode.
1501 * \param file_priv DRM file private.
1502 * \param cmd command.
1503 * \param data user argument, pointing to a drm_wait_vblank structure.
1504 * \return zero on success or a negative number on failure.
1506 * This function enables the vblank interrupt on the pipe requested, then
1507 * sleeps waiting for the requested sequence number to occur, and drops
1508 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1509 * after a timeout with no further vblank waits scheduled).
1511 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1512 struct drm_file
*file_priv
)
1514 struct drm_vblank_crtc
*vblank
;
1515 union drm_wait_vblank
*vblwait
= data
;
1517 unsigned int flags
, seq
, crtc
, high_crtc
;
1519 if (!dev
->irq_enabled
)
1522 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1525 if (vblwait
->request
.type
&
1526 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1527 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1528 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1529 vblwait
->request
.type
,
1530 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1531 _DRM_VBLANK_HIGH_CRTC_MASK
));
1535 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1536 high_crtc
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1538 crtc
= high_crtc
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1540 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1541 if (crtc
>= dev
->num_crtcs
)
1544 vblank
= &dev
->vblank
[crtc
];
1546 ret
= drm_vblank_get(dev
, crtc
);
1548 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1551 seq
= drm_vblank_count(dev
, crtc
);
1553 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1554 case _DRM_VBLANK_RELATIVE
:
1555 vblwait
->request
.sequence
+= seq
;
1556 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1557 case _DRM_VBLANK_ABSOLUTE
:
1564 if (flags
& _DRM_VBLANK_EVENT
) {
1565 /* must hold on to the vblank ref until the event fires
1566 * drm_vblank_put will be called asynchronously
1568 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1571 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1572 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1573 vblwait
->request
.sequence
= seq
+ 1;
1576 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1577 vblwait
->request
.sequence
, crtc
);
1578 vblank
->last_wait
= vblwait
->request
.sequence
;
1579 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1580 (((drm_vblank_count(dev
, crtc
) -
1581 vblwait
->request
.sequence
) <= (1 << 23)) ||
1583 !dev
->irq_enabled
));
1585 if (ret
!= -EINTR
) {
1588 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1589 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1590 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1592 DRM_DEBUG("returning %d to client\n",
1593 vblwait
->reply
.sequence
);
1595 DRM_DEBUG("vblank wait interrupted by signal\n");
1599 drm_vblank_put(dev
, crtc
);
1603 static void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1605 struct drm_pending_vblank_event
*e
, *t
;
1609 assert_spin_locked(&dev
->event_lock
);
1611 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1613 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1614 if (e
->pipe
!= crtc
)
1616 if ((seq
- e
->event
.sequence
) > (1<<23))
1619 DRM_DEBUG("vblank event on %d, current %d\n",
1620 e
->event
.sequence
, seq
);
1622 list_del(&e
->base
.link
);
1623 drm_vblank_put(dev
, e
->pipe
);
1624 send_vblank_event(dev
, e
, seq
, &now
);
1627 trace_drm_vblank_event(crtc
, seq
);
1631 * drm_handle_vblank - handle a vblank event
1633 * @crtc: where this event occurred
1635 * Drivers should call this routine in their vblank interrupt handlers to
1636 * update the vblank counter and send any signals that may be pending.
1638 * This is the legacy version of drm_crtc_handle_vblank().
1640 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1642 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[crtc
];
1645 struct timeval tvblank
;
1646 unsigned long irqflags
;
1648 if (!dev
->num_crtcs
)
1651 if (WARN_ON(crtc
>= dev
->num_crtcs
))
1654 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1656 /* Need timestamp lock to prevent concurrent execution with
1657 * vblank enable/disable, as this would cause inconsistent
1658 * or corrupted timestamps and vblank counts.
1660 spin_lock(&dev
->vblank_time_lock
);
1662 /* Vblank irq handling disabled. Nothing to do. */
1663 if (!vblank
->enabled
) {
1664 spin_unlock(&dev
->vblank_time_lock
);
1665 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1669 /* Fetch corresponding timestamp for this vblank interval from
1670 * driver and store it in proper slot of timestamp ringbuffer.
1673 /* Get current timestamp and count. */
1674 vblcount
= atomic_read(&vblank
->count
);
1675 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1677 /* Compute time difference to timestamp of last vblank */
1678 diff_ns
= timeval_to_ns(&tvblank
) -
1679 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1681 /* Update vblank timestamp and count if at least
1682 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1683 * difference between last stored timestamp and current
1684 * timestamp. A smaller difference means basically
1685 * identical timestamps. Happens if this vblank has
1686 * been already processed and this is a redundant call,
1687 * e.g., due to spurious vblank interrupts. We need to
1688 * ignore those for accounting.
1690 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1691 /* Store new timestamp in ringbuffer. */
1692 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1694 /* Increment cooked vblank count. This also atomically commits
1695 * the timestamp computed above.
1697 smp_mb__before_atomic();
1698 atomic_inc(&vblank
->count
);
1699 smp_mb__after_atomic();
1701 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1702 crtc
, (int) diff_ns
);
1705 spin_unlock(&dev
->vblank_time_lock
);
1707 wake_up(&vblank
->queue
);
1708 drm_handle_vblank_events(dev
, crtc
);
1710 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1714 EXPORT_SYMBOL(drm_handle_vblank
);
1717 * drm_crtc_handle_vblank - handle a vblank event
1718 * @crtc: where this event occurred
1720 * Drivers should call this routine in their vblank interrupt handlers to
1721 * update the vblank counter and send any signals that may be pending.
1723 * This is the native KMS version of drm_handle_vblank().
1726 * True if the event was successfully handled, false on failure.
1728 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1730 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1732 EXPORT_SYMBOL(drm_crtc_handle_vblank
);