2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
48 #define DRM_TIMESTAMP_MAXRETRIES 3
50 /* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
53 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
56 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
57 struct timeval
*tvblank
, unsigned flags
);
59 static unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
62 * Default to use monotonic timestamps for wait-for-vblank and page-flip
65 unsigned int drm_timestamp_monotonic
= 1;
67 static int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
69 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
70 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
71 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
72 MODULE_PARM_DESC(vblankoffdelay
, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
73 MODULE_PARM_DESC(timestamp_precision_usec
, "Max. error on timestamps [usecs]");
74 MODULE_PARM_DESC(timestamp_monotonic
, "Use monotonic timestamps");
76 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
78 struct timeval
*t_vblank
, u32 last
)
80 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
82 assert_spin_locked(&dev
->vblank_time_lock
);
86 write_seqlock(&vblank
->seqlock
);
87 vblank
->time
= *t_vblank
;
88 vblank
->count
+= vblank_count_inc
;
89 write_sequnlock(&vblank
->seqlock
);
93 * Reset the stored timestamp for the current vblank count to correspond
94 * to the last vblank occurred.
96 * Only to be called from drm_vblank_on().
98 * Note: caller must hold dev->vbl_lock since this reads & writes
99 * device vblank fields.
101 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
105 struct timeval t_vblank
;
106 int count
= DRM_TIMESTAMP_MAXRETRIES
;
108 spin_lock(&dev
->vblank_time_lock
);
111 * sample the current counter to avoid random jumps
112 * when drm_vblank_enable() applies the diff
115 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
116 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
117 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
120 * Only reinitialize corresponding vblank timestamp if high-precision query
121 * available and didn't fail. Otherwise reinitialize delayed at next vblank
122 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
125 t_vblank
= (struct timeval
) {0, 0};
128 * +1 to make sure user will never see the same
129 * vblank counter value before and after a modeset
131 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
133 spin_unlock(&dev
->vblank_time_lock
);
137 * Call back into the driver to update the appropriate vblank counter
138 * (specified by @pipe). Deal with wraparound, if it occurred, and
139 * update the last read value so we can deal with wraparound on the next
142 * Only necessary when going from off->on, to account for frames we
143 * didn't get an interrupt for.
145 * Note: caller must hold dev->vbl_lock since this reads & writes
146 * device vblank fields.
148 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
151 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
152 u32 cur_vblank
, diff
;
154 struct timeval t_vblank
;
155 int count
= DRM_TIMESTAMP_MAXRETRIES
;
156 int framedur_ns
= vblank
->framedur_ns
;
159 * Interrupts were disabled prior to this call, so deal with counter
161 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
162 * here if the register is small or we had vblank interrupts off for
165 * We repeat the hardware vblank counter & timestamp query until
166 * we get consistent results. This to prevent races between gpu
167 * updating its hardware counter while we are retrieving the
168 * corresponding vblank timestamp.
171 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
172 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
173 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
175 if (dev
->max_vblank_count
!= 0) {
176 /* trust the hw counter when it's around */
177 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
178 } else if (rc
&& framedur_ns
) {
179 const struct timeval
*t_old
;
182 t_old
= &vblank
->time
;
183 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
186 * Figure out how many vblanks we've missed based
187 * on the difference in the timestamps and the
188 * frame/field duration.
190 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
192 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
193 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
194 " diff_ns = %lld, framedur_ns = %d)\n",
195 pipe
, (long long) diff_ns
, framedur_ns
);
197 /* some kind of default for drivers w/o accurate vbl timestamping */
198 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
202 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
203 * interval? If so then vblank irqs keep running and it will likely
204 * happen that the hardware vblank counter is not trustworthy as it
205 * might reset at some point in that interval and vblank timestamps
206 * are not trustworthy either in that interval. Iow. this can result
207 * in a bogus diff >> 1 which must be avoided as it would cause
208 * random large forward jumps of the software vblank counter.
210 if (diff
> 1 && (vblank
->inmodeset
& 0x2)) {
211 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
212 " due to pre-modeset.\n", pipe
, diff
);
216 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
217 " current=%u, diff=%u, hw=%u hw_last=%u\n",
218 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
221 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
226 * Only reinitialize corresponding vblank timestamp if high-precision query
227 * available and didn't fail, or we were called from the vblank interrupt.
228 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
229 * for now, to mark the vblanktimestamp as invalid.
231 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
232 t_vblank
= (struct timeval
) {0, 0};
234 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
238 * drm_accurate_vblank_count - retrieve the master vblank counter
239 * @crtc: which counter to retrieve
241 * This function is similar to @drm_crtc_vblank_count but this
242 * function interpolates to handle a race with vblank irq's.
244 * This is mostly useful for hardware that can obtain the scanout
245 * position, but doesn't have a frame counter.
247 u32
drm_accurate_vblank_count(struct drm_crtc
*crtc
)
249 struct drm_device
*dev
= crtc
->dev
;
250 unsigned int pipe
= drm_crtc_index(crtc
);
254 WARN(!dev
->driver
->get_vblank_timestamp
,
255 "This function requires support for accurate vblank timestamps.");
257 spin_lock_irqsave(&dev
->vblank_time_lock
, flags
);
259 drm_update_vblank_count(dev
, pipe
, 0);
260 vblank
= drm_vblank_count(dev
, pipe
);
262 spin_unlock_irqrestore(&dev
->vblank_time_lock
, flags
);
266 EXPORT_SYMBOL(drm_accurate_vblank_count
);
269 * Disable vblank irq's on crtc, make sure that last vblank count
270 * of hardware and corresponding consistent software vblank counter
271 * are preserved, even if there are any spurious vblank irq's after
274 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
276 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
277 unsigned long irqflags
;
279 /* Prevent vblank irq processing while disabling vblank irqs,
280 * so no updates of timestamps or count can happen after we've
281 * disabled. Needed to prevent races in case of delayed irq's.
283 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
286 * Only disable vblank interrupts if they're enabled. This avoids
287 * calling the ->disable_vblank() operation in atomic context with the
288 * hardware potentially runtime suspended.
290 if (vblank
->enabled
) {
291 dev
->driver
->disable_vblank(dev
, pipe
);
292 vblank
->enabled
= false;
296 * Always update the count and timestamp to maintain the
297 * appearance that the counter has been ticking all along until
298 * this time. This makes the count account for the entire time
299 * between drm_vblank_on() and drm_vblank_off().
301 drm_update_vblank_count(dev
, pipe
, 0);
303 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
306 static void vblank_disable_fn(unsigned long arg
)
308 struct drm_vblank_crtc
*vblank
= (void *)arg
;
309 struct drm_device
*dev
= vblank
->dev
;
310 unsigned int pipe
= vblank
->pipe
;
311 unsigned long irqflags
;
313 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
314 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
315 DRM_DEBUG("disabling vblank on crtc %u\n", pipe
);
316 vblank_disable_and_save(dev
, pipe
);
318 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
322 * drm_vblank_cleanup - cleanup vblank support
325 * This function cleans up any resources allocated in drm_vblank_init.
327 void drm_vblank_cleanup(struct drm_device
*dev
)
331 /* Bail if the driver didn't call drm_vblank_init() */
332 if (dev
->num_crtcs
== 0)
335 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
336 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
338 WARN_ON(vblank
->enabled
&&
339 drm_core_check_feature(dev
, DRIVER_MODESET
));
341 del_timer_sync(&vblank
->disable_timer
);
348 EXPORT_SYMBOL(drm_vblank_cleanup
);
351 * drm_vblank_init - initialize vblank support
353 * @num_crtcs: number of CRTCs supported by @dev
355 * This function initializes vblank support for @num_crtcs display pipelines.
358 * Zero on success or a negative error code on failure.
360 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
365 spin_lock_init(&dev
->vbl_lock
);
366 spin_lock_init(&dev
->vblank_time_lock
);
368 dev
->num_crtcs
= num_crtcs
;
370 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
374 for (i
= 0; i
< num_crtcs
; i
++) {
375 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
379 init_waitqueue_head(&vblank
->queue
);
380 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
381 (unsigned long)vblank
);
382 seqlock_init(&vblank
->seqlock
);
385 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
387 /* Driver specific high-precision vblank timestamping supported? */
388 if (dev
->driver
->get_vblank_timestamp
)
389 DRM_INFO("Driver supports precise vblank timestamp query.\n");
391 DRM_INFO("No driver support for vblank timestamp query.\n");
393 /* Must have precise timestamping for reliable vblank instant disable */
394 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
395 dev
->vblank_disable_immediate
= false;
396 DRM_INFO("Setting vblank_disable_immediate to false because "
397 "get_vblank_timestamp == NULL\n");
406 EXPORT_SYMBOL(drm_vblank_init
);
408 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
410 struct drm_device
*dev
= cookie
;
412 if (dev
->driver
->vgaarb_irq
) {
413 dev
->driver
->vgaarb_irq(dev
, state
);
417 if (!dev
->irq_enabled
)
421 if (dev
->driver
->irq_uninstall
)
422 dev
->driver
->irq_uninstall(dev
);
424 if (dev
->driver
->irq_preinstall
)
425 dev
->driver
->irq_preinstall(dev
);
426 if (dev
->driver
->irq_postinstall
)
427 dev
->driver
->irq_postinstall(dev
);
432 * drm_irq_install - install IRQ handler
434 * @irq: IRQ number to install the handler for
436 * Initializes the IRQ related data. Installs the handler, calling the driver
437 * irq_preinstall() and irq_postinstall() functions before and after the
440 * This is the simplified helper interface provided for drivers with no special
441 * needs. Drivers which need to install interrupt handlers for multiple
442 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
443 * that vblank interrupts are available.
446 * Zero on success or a negative error code on failure.
448 int drm_irq_install(struct drm_device
*dev
, int irq
)
451 unsigned long sh_flags
= 0;
453 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
459 /* Driver must have been initialized */
460 if (!dev
->dev_private
)
463 if (dev
->irq_enabled
)
465 dev
->irq_enabled
= true;
467 DRM_DEBUG("irq=%d\n", irq
);
469 /* Before installing handler */
470 if (dev
->driver
->irq_preinstall
)
471 dev
->driver
->irq_preinstall(dev
);
473 /* Install handler */
474 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
475 sh_flags
= IRQF_SHARED
;
477 ret
= request_irq(irq
, dev
->driver
->irq_handler
,
478 sh_flags
, dev
->driver
->name
, dev
);
481 dev
->irq_enabled
= false;
485 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
486 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
488 /* After installing handler */
489 if (dev
->driver
->irq_postinstall
)
490 ret
= dev
->driver
->irq_postinstall(dev
);
493 dev
->irq_enabled
= false;
494 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
495 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
503 EXPORT_SYMBOL(drm_irq_install
);
506 * drm_irq_uninstall - uninstall the IRQ handler
509 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
510 * This should only be called by drivers which used drm_irq_install() to set up
511 * their interrupt handler. Other drivers must only reset
512 * drm_device->irq_enabled to false.
514 * Note that for kernel modesetting drivers it is a bug if this function fails.
515 * The sanity checks are only to catch buggy user modesetting drivers which call
516 * the same function through an ioctl.
519 * Zero on success or a negative error code on failure.
521 int drm_irq_uninstall(struct drm_device
*dev
)
523 unsigned long irqflags
;
527 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
530 irq_enabled
= dev
->irq_enabled
;
531 dev
->irq_enabled
= false;
534 * Wake up any waiters so they don't hang. This is just to paper over
535 * isssues for UMS drivers which aren't in full control of their
536 * vblank/irq handling. KMS drivers must ensure that vblanks are all
537 * disabled when uninstalling the irq handler.
539 if (dev
->num_crtcs
) {
540 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
541 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
542 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
544 if (!vblank
->enabled
)
547 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
549 vblank_disable_and_save(dev
, i
);
550 wake_up(&vblank
->queue
);
552 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
558 DRM_DEBUG("irq=%d\n", dev
->irq
);
560 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
561 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
563 if (dev
->driver
->irq_uninstall
)
564 dev
->driver
->irq_uninstall(dev
);
566 free_irq(dev
->irq
, dev
);
570 EXPORT_SYMBOL(drm_irq_uninstall
);
575 * \param inode device inode.
576 * \param file_priv DRM file private.
577 * \param cmd command.
578 * \param arg user argument, pointing to a drm_control structure.
579 * \return zero on success or a negative number on failure.
581 * Calls irq_install() or irq_uninstall() according to \p arg.
583 int drm_control(struct drm_device
*dev
, void *data
,
584 struct drm_file
*file_priv
)
586 struct drm_control
*ctl
= data
;
589 /* if we haven't irq we fallback for compatibility reasons -
590 * this used to be a separate function in drm_dma.h
593 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
595 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
597 /* UMS was only ever support on pci devices. */
598 if (WARN_ON(!dev
->pdev
))
602 case DRM_INST_HANDLER
:
603 irq
= dev
->pdev
->irq
;
605 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
608 mutex_lock(&dev
->struct_mutex
);
609 ret
= drm_irq_install(dev
, irq
);
610 mutex_unlock(&dev
->struct_mutex
);
613 case DRM_UNINST_HANDLER
:
614 mutex_lock(&dev
->struct_mutex
);
615 ret
= drm_irq_uninstall(dev
);
616 mutex_unlock(&dev
->struct_mutex
);
625 * drm_calc_timestamping_constants - calculate vblank timestamp constants
626 * @crtc: drm_crtc whose timestamp constants should be updated.
627 * @mode: display mode containing the scanout timings
629 * Calculate and store various constants which are later
630 * needed by vblank and swap-completion timestamping, e.g,
631 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
632 * derived from CRTC's true scanout timing, so they take
633 * things like panel scaling or other adjustments into account.
635 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
636 const struct drm_display_mode
*mode
)
638 struct drm_device
*dev
= crtc
->dev
;
639 unsigned int pipe
= drm_crtc_index(crtc
);
640 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
641 int linedur_ns
= 0, framedur_ns
= 0;
642 int dotclock
= mode
->crtc_clock
;
647 if (WARN_ON(pipe
>= dev
->num_crtcs
))
650 /* Valid dotclock? */
652 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
655 * Convert scanline length in pixels and video
656 * dot clock to line duration and frame duration
659 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
660 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
663 * Fields of interlaced scanout modes are only half a frame duration.
665 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
668 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
671 vblank
->linedur_ns
= linedur_ns
;
672 vblank
->framedur_ns
= framedur_ns
;
674 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
675 crtc
->base
.id
, mode
->crtc_htotal
,
676 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
677 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
678 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
680 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
683 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
685 * @pipe: index of CRTC whose vblank timestamp to retrieve
686 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
687 * On return contains true maximum error of timestamp
688 * @vblank_time: Pointer to struct timeval which should receive the timestamp
689 * @flags: Flags to pass to driver:
691 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
692 * @mode: mode which defines the scanout timings
694 * Implements calculation of exact vblank timestamps from given drm_display_mode
695 * timings and current video scanout position of a CRTC. This can be called from
696 * within get_vblank_timestamp() implementation of a kms driver to implement the
697 * actual timestamping.
699 * Should return timestamps conforming to the OML_sync_control OpenML
700 * extension specification. The timestamp corresponds to the end of
701 * the vblank interval, aka start of scanout of topmost-leftmost display
702 * pixel in the following video frame.
704 * Requires support for optional dev->driver->get_scanout_position()
705 * in kms driver, plus a bit of setup code to provide a drm_display_mode
706 * that corresponds to the true scanout timing.
708 * The current implementation only handles standard video modes. It
709 * returns as no operation if a doublescan or interlaced video mode is
710 * active. Higher level code is expected to handle this.
713 * Negative value on error, failure or if not supported in current
716 * -EINVAL - Invalid CRTC.
717 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
718 * -ENOTSUPP - Function not supported in current display mode.
719 * -EIO - Failed, e.g., due to failed scanout position query.
721 * Returns or'ed positive status flags on success:
723 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
724 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
727 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
730 struct timeval
*vblank_time
,
732 const struct drm_display_mode
*mode
)
734 struct timeval tv_etime
;
735 ktime_t stime
, etime
;
736 unsigned int vbl_status
;
737 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
739 int delta_ns
, duration_ns
;
741 if (pipe
>= dev
->num_crtcs
) {
742 DRM_ERROR("Invalid crtc %u\n", pipe
);
746 /* Scanout position query not supported? Should not happen. */
747 if (!dev
->driver
->get_scanout_position
) {
748 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
752 /* If mode timing undefined, just return as no-op:
753 * Happens during initial modesetting of a crtc.
755 if (mode
->crtc_clock
== 0) {
756 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe
);
760 /* Get current scanout position with system timestamp.
761 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
762 * if single query takes longer than max_error nanoseconds.
764 * This guarantees a tight bound on maximum error if
765 * code gets preempted or delayed for some reason.
767 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
769 * Get vertical and horizontal scanout position vpos, hpos,
770 * and bounding timestamps stime, etime, pre/post query.
772 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
777 /* Return as no-op if scanout query unsupported or failed. */
778 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
779 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
784 /* Compute uncertainty in timestamp of scanout position query. */
785 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
787 /* Accept result with < max_error nsecs timing uncertainty. */
788 if (duration_ns
<= *max_error
)
792 /* Noisy system timing? */
793 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
794 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
795 pipe
, duration_ns
/1000, *max_error
/1000, i
);
798 /* Return upper bound of timestamp precision error. */
799 *max_error
= duration_ns
;
801 /* Check if in vblank area:
802 * vpos is >=0 in video scanout area, but negative
803 * within vblank area, counting down the number of lines until
806 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
807 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
809 /* Convert scanout position into elapsed time at raw_time query
810 * since start of scanout at first display scanline. delta_ns
811 * can be negative if start of scanout hasn't happened yet.
813 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
816 if (!drm_timestamp_monotonic
)
817 etime
= ktime_mono_to_real(etime
);
819 /* save this only for debugging purposes */
820 tv_etime
= ktime_to_timeval(etime
);
821 /* Subtract time delta from raw timestamp to get final
822 * vblank_time timestamp for end of vblank.
824 etime
= ktime_sub_ns(etime
, delta_ns
);
825 *vblank_time
= ktime_to_timeval(etime
);
827 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
828 pipe
, vbl_status
, hpos
, vpos
,
829 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
830 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
831 duration_ns
/1000, i
);
835 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
837 static struct timeval
get_drm_timestamp(void)
841 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
842 return ktime_to_timeval(now
);
846 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
849 * @pipe: index of CRTC whose vblank timestamp to retrieve
850 * @tvblank: Pointer to target struct timeval which should receive the timestamp
851 * @flags: Flags to pass to driver:
853 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
855 * Fetches the system timestamp corresponding to the time of the most recent
856 * vblank interval on specified CRTC. May call into kms-driver to
857 * compute the timestamp with a high-precision GPU specific method.
859 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
860 * call, i.e., it isn't very precisely locked to the true vblank.
863 * True if timestamp is considered to be very precise, false otherwise.
866 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
867 struct timeval
*tvblank
, unsigned flags
)
871 /* Define requested maximum error on timestamps (nanoseconds). */
872 int max_error
= (int) drm_timestamp_precision
* 1000;
874 /* Query driver if possible and precision timestamping enabled. */
875 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
876 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
882 /* GPU high precision timestamp query unsupported or failed.
883 * Return current monotonic/gettimeofday timestamp as best estimate.
885 *tvblank
= get_drm_timestamp();
891 * drm_vblank_count - retrieve "cooked" vblank counter value
893 * @pipe: index of CRTC for which to retrieve the counter
895 * Fetches the "cooked" vblank count value that represents the number of
896 * vblank events since the system was booted, including lost events due to
897 * modesetting activity.
899 * This is the legacy version of drm_crtc_vblank_count().
902 * The software vblank counter.
904 u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
906 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
908 if (WARN_ON(pipe
>= dev
->num_crtcs
))
911 return vblank
->count
;
913 EXPORT_SYMBOL(drm_vblank_count
);
916 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
917 * @crtc: which counter to retrieve
919 * Fetches the "cooked" vblank count value that represents the number of
920 * vblank events since the system was booted, including lost events due to
921 * modesetting activity.
923 * This is the native KMS version of drm_vblank_count().
926 * The software vblank counter.
928 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
930 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
932 EXPORT_SYMBOL(drm_crtc_vblank_count
);
935 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
936 * system timestamp corresponding to that vblank counter value.
938 * @pipe: index of CRTC whose counter to retrieve
939 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
941 * Fetches the "cooked" vblank count value that represents the number of
942 * vblank events since the system was booted, including lost events due to
943 * modesetting activity. Returns corresponding system timestamp of the time
944 * of the vblank interval that corresponds to the current vblank counter value.
946 * This is the legacy version of drm_crtc_vblank_count_and_time().
948 u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
949 struct timeval
*vblanktime
)
951 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
955 if (WARN_ON(pipe
>= dev
->num_crtcs
))
959 seq
= read_seqbegin(&vblank
->seqlock
);
960 vblank_count
= vblank
->count
;
961 *vblanktime
= vblank
->time
;
962 } while (read_seqretry(&vblank
->seqlock
, seq
));
966 EXPORT_SYMBOL(drm_vblank_count_and_time
);
969 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
970 * and the system timestamp corresponding to that vblank counter value
971 * @crtc: which counter to retrieve
972 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
974 * Fetches the "cooked" vblank count value that represents the number of
975 * vblank events since the system was booted, including lost events due to
976 * modesetting activity. Returns corresponding system timestamp of the time
977 * of the vblank interval that corresponds to the current vblank counter value.
979 * This is the native KMS version of drm_vblank_count_and_time().
981 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
982 struct timeval
*vblanktime
)
984 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
987 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
989 static void send_vblank_event(struct drm_device
*dev
,
990 struct drm_pending_vblank_event
*e
,
991 unsigned long seq
, struct timeval
*now
)
993 e
->event
.sequence
= seq
;
994 e
->event
.tv_sec
= now
->tv_sec
;
995 e
->event
.tv_usec
= now
->tv_usec
;
997 drm_send_event_locked(dev
, &e
->base
);
999 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1004 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1005 * @crtc: the source CRTC of the vblank event
1006 * @e: the event to send
1008 * A lot of drivers need to generate vblank events for the very next vblank
1009 * interrupt. For example when the page flip interrupt happens when the page
1010 * flip gets armed, but not when it actually executes within the next vblank
1011 * period. This helper function implements exactly the required vblank arming
1014 * Caller must hold event lock. Caller must also hold a vblank reference for
1015 * the event @e, which will be dropped when the next vblank arrives.
1017 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1018 struct drm_pending_vblank_event
*e
)
1020 struct drm_device
*dev
= crtc
->dev
;
1021 unsigned int pipe
= drm_crtc_index(crtc
);
1023 assert_spin_locked(&dev
->event_lock
);
1026 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1027 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1029 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1032 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1033 * @crtc: the source CRTC of the vblank event
1034 * @e: the event to send
1036 * Updates sequence # and timestamp on event, and sends it to userspace.
1037 * Caller must hold event lock.
1039 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1040 struct drm_pending_vblank_event
*e
)
1042 struct drm_device
*dev
= crtc
->dev
;
1043 unsigned int seq
, pipe
= drm_crtc_index(crtc
);
1046 if (dev
->num_crtcs
> 0) {
1047 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1051 now
= get_drm_timestamp();
1054 send_vblank_event(dev
, e
, seq
, &now
);
1056 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1059 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1064 * Zero on success or a negative error code on failure.
1066 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1068 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1071 assert_spin_locked(&dev
->vbl_lock
);
1073 spin_lock(&dev
->vblank_time_lock
);
1075 if (!vblank
->enabled
) {
1077 * Enable vblank irqs under vblank_time_lock protection.
1078 * All vblank count & timestamp updates are held off
1079 * until we are done reinitializing master counter and
1080 * timestamps. Filtercode in drm_handle_vblank() will
1081 * prevent double-accounting of same vblank interval.
1083 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1084 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1086 atomic_dec(&vblank
->refcount
);
1088 vblank
->enabled
= true;
1089 drm_update_vblank_count(dev
, pipe
, 0);
1093 spin_unlock(&dev
->vblank_time_lock
);
1099 * drm_vblank_get - get a reference count on vblank events
1101 * @pipe: index of CRTC to own
1103 * Acquire a reference count on vblank events to avoid having them disabled
1106 * This is the legacy version of drm_crtc_vblank_get().
1109 * Zero on success or a negative error code on failure.
1111 static int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1113 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1114 unsigned long irqflags
;
1117 if (!dev
->num_crtcs
)
1120 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1123 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1124 /* Going from 0->1 means we have to enable interrupts again */
1125 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1126 ret
= drm_vblank_enable(dev
, pipe
);
1128 if (!vblank
->enabled
) {
1129 atomic_dec(&vblank
->refcount
);
1133 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1139 * drm_crtc_vblank_get - get a reference count on vblank events
1140 * @crtc: which CRTC to own
1142 * Acquire a reference count on vblank events to avoid having them disabled
1146 * Zero on success or a negative error code on failure.
1148 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1150 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1152 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1155 * drm_vblank_put - release ownership of vblank events
1157 * @pipe: index of CRTC to release
1159 * Release ownership of a given vblank counter, turning off interrupts
1160 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1162 * This is the legacy version of drm_crtc_vblank_put().
1164 static void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1166 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1168 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1171 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1174 /* Last user schedules interrupt disable */
1175 if (atomic_dec_and_test(&vblank
->refcount
)) {
1176 if (drm_vblank_offdelay
== 0)
1178 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1179 vblank_disable_fn((unsigned long)vblank
);
1181 mod_timer(&vblank
->disable_timer
,
1182 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1187 * drm_crtc_vblank_put - give up ownership of vblank events
1188 * @crtc: which counter to give up
1190 * Release ownership of a given vblank counter, turning off interrupts
1191 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1193 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1195 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1197 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1200 * drm_wait_one_vblank - wait for one vblank
1204 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1205 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1206 * due to lack of driver support or because the crtc is off.
1208 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1210 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1214 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1217 ret
= drm_vblank_get(dev
, pipe
);
1218 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1221 last
= drm_vblank_count(dev
, pipe
);
1223 ret
= wait_event_timeout(vblank
->queue
,
1224 last
!= drm_vblank_count(dev
, pipe
),
1225 msecs_to_jiffies(100));
1227 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1229 drm_vblank_put(dev
, pipe
);
1231 EXPORT_SYMBOL(drm_wait_one_vblank
);
1234 * drm_crtc_wait_one_vblank - wait for one vblank
1237 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1238 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1239 * due to lack of driver support or because the crtc is off.
1241 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1243 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1245 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1248 * drm_vblank_off - disable vblank events on a CRTC
1252 * Drivers can use this function to shut down the vblank interrupt handling when
1253 * disabling a crtc. This function ensures that the latest vblank frame count is
1254 * stored so that drm_vblank_on() can restore it again.
1256 * Drivers must use this function when the hardware vblank counter can get
1257 * reset, e.g. when suspending.
1259 * This is the legacy version of drm_crtc_vblank_off().
1261 void drm_vblank_off(struct drm_device
*dev
, unsigned int pipe
)
1263 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1264 struct drm_pending_vblank_event
*e
, *t
;
1266 unsigned long irqflags
;
1269 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1272 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1274 spin_lock(&dev
->vbl_lock
);
1275 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1276 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1278 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1279 if (drm_core_check_feature(dev
, DRIVER_ATOMIC
) || !vblank
->inmodeset
)
1280 vblank_disable_and_save(dev
, pipe
);
1282 wake_up(&vblank
->queue
);
1285 * Prevent subsequent drm_vblank_get() from re-enabling
1286 * the vblank interrupt by bumping the refcount.
1288 if (!vblank
->inmodeset
) {
1289 atomic_inc(&vblank
->refcount
);
1290 vblank
->inmodeset
= 1;
1292 spin_unlock(&dev
->vbl_lock
);
1294 /* Send any queued vblank events, lest the natives grow disquiet */
1295 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1297 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1298 if (e
->pipe
!= pipe
)
1300 DRM_DEBUG("Sending premature vblank event on disable: "
1301 "wanted %d, current %d\n",
1302 e
->event
.sequence
, seq
);
1303 list_del(&e
->base
.link
);
1304 drm_vblank_put(dev
, pipe
);
1305 send_vblank_event(dev
, e
, seq
, &now
);
1307 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1309 EXPORT_SYMBOL(drm_vblank_off
);
1312 * drm_crtc_vblank_off - disable vblank events on a CRTC
1313 * @crtc: CRTC in question
1315 * Drivers can use this function to shut down the vblank interrupt handling when
1316 * disabling a crtc. This function ensures that the latest vblank frame count is
1317 * stored so that drm_vblank_on can restore it again.
1319 * Drivers must use this function when the hardware vblank counter can get
1320 * reset, e.g. when suspending.
1322 * This is the native kms version of drm_vblank_off().
1324 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1326 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1328 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1331 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1332 * @crtc: CRTC in question
1334 * Drivers can use this function to reset the vblank state to off at load time.
1335 * Drivers should use this together with the drm_crtc_vblank_off() and
1336 * drm_crtc_vblank_on() functions. The difference compared to
1337 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1338 * and hence doesn't need to call any driver hooks.
1340 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1342 struct drm_device
*dev
= crtc
->dev
;
1343 unsigned long irqflags
;
1344 unsigned int pipe
= drm_crtc_index(crtc
);
1345 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1347 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1349 * Prevent subsequent drm_vblank_get() from enabling the vblank
1350 * interrupt by bumping the refcount.
1352 if (!vblank
->inmodeset
) {
1353 atomic_inc(&vblank
->refcount
);
1354 vblank
->inmodeset
= 1;
1356 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1358 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1360 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1363 * drm_vblank_on - enable vblank events on a CRTC
1367 * This functions restores the vblank interrupt state captured with
1368 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1369 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1370 * in driver load code to reflect the current hardware state of the crtc.
1372 * This is the legacy version of drm_crtc_vblank_on().
1374 void drm_vblank_on(struct drm_device
*dev
, unsigned int pipe
)
1376 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1377 unsigned long irqflags
;
1379 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1382 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1383 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1384 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1386 /* Drop our private "prevent drm_vblank_get" refcount */
1387 if (vblank
->inmodeset
) {
1388 atomic_dec(&vblank
->refcount
);
1389 vblank
->inmodeset
= 0;
1392 drm_reset_vblank_timestamp(dev
, pipe
);
1395 * re-enable interrupts if there are users left, or the
1396 * user wishes vblank interrupts to be enabled all the time.
1398 if (atomic_read(&vblank
->refcount
) != 0 || drm_vblank_offdelay
== 0)
1399 WARN_ON(drm_vblank_enable(dev
, pipe
));
1400 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1402 EXPORT_SYMBOL(drm_vblank_on
);
1405 * drm_crtc_vblank_on - enable vblank events on a CRTC
1406 * @crtc: CRTC in question
1408 * This functions restores the vblank interrupt state captured with
1409 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1410 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1411 * in driver load code to reflect the current hardware state of the crtc.
1413 * This is the native kms version of drm_vblank_on().
1415 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1417 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1419 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1422 * drm_vblank_pre_modeset - account for vblanks across mode sets
1426 * Account for vblank events across mode setting events, which will likely
1427 * reset the hardware frame counter.
1429 * This is done by grabbing a temporary vblank reference to ensure that the
1430 * vblank interrupt keeps running across the modeset sequence. With this the
1431 * software-side vblank frame counting will ensure that there are no jumps or
1434 * Unfortunately this approach is racy and also doesn't work when the vblank
1435 * interrupt stops running, e.g. across system suspend resume. It is therefore
1436 * highly recommended that drivers use the newer drm_vblank_off() and
1437 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1438 * using "cooked" software vblank frame counters and not relying on any hardware
1441 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1444 void drm_vblank_pre_modeset(struct drm_device
*dev
, unsigned int pipe
)
1446 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1448 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1449 if (!dev
->num_crtcs
)
1452 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1456 * To avoid all the problems that might happen if interrupts
1457 * were enabled/disabled around or between these calls, we just
1458 * have the kernel take a reference on the CRTC (just once though
1459 * to avoid corrupting the count if multiple, mismatch calls occur),
1460 * so that interrupts remain enabled in the interim.
1462 if (!vblank
->inmodeset
) {
1463 vblank
->inmodeset
= 0x1;
1464 if (drm_vblank_get(dev
, pipe
) == 0)
1465 vblank
->inmodeset
|= 0x2;
1468 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1471 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1475 * This function again drops the temporary vblank reference acquired in
1476 * drm_vblank_pre_modeset.
1478 void drm_vblank_post_modeset(struct drm_device
*dev
, unsigned int pipe
)
1480 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1481 unsigned long irqflags
;
1483 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1484 if (!dev
->num_crtcs
)
1487 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1490 if (vblank
->inmodeset
) {
1491 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1492 drm_reset_vblank_timestamp(dev
, pipe
);
1493 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1495 if (vblank
->inmodeset
& 0x2)
1496 drm_vblank_put(dev
, pipe
);
1498 vblank
->inmodeset
= 0;
1501 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1504 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1505 * @DRM_IOCTL_ARGS: standard ioctl arguments
1507 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1508 * ioctls around modesetting so that any lost vblank events are accounted for.
1510 * Generally the counter will reset across mode sets. If interrupts are
1511 * enabled around this call, we don't have to do anything since the counter
1512 * will have already been incremented.
1514 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1515 struct drm_file
*file_priv
)
1517 struct drm_modeset_ctl
*modeset
= data
;
1520 /* If drm_vblank_init() hasn't been called yet, just no-op */
1521 if (!dev
->num_crtcs
)
1524 /* KMS drivers handle this internally */
1525 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1528 pipe
= modeset
->crtc
;
1529 if (pipe
>= dev
->num_crtcs
)
1532 switch (modeset
->cmd
) {
1533 case _DRM_PRE_MODESET
:
1534 drm_vblank_pre_modeset(dev
, pipe
);
1536 case _DRM_POST_MODESET
:
1537 drm_vblank_post_modeset(dev
, pipe
);
1546 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1547 union drm_wait_vblank
*vblwait
,
1548 struct drm_file
*file_priv
)
1550 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1551 struct drm_pending_vblank_event
*e
;
1553 unsigned long flags
;
1557 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1564 e
->base
.pid
= current
->pid
;
1565 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1566 e
->event
.base
.length
= sizeof(e
->event
);
1567 e
->event
.user_data
= vblwait
->request
.signal
;
1569 spin_lock_irqsave(&dev
->event_lock
, flags
);
1572 * drm_vblank_off() might have been called after we called
1573 * drm_vblank_get(). drm_vblank_off() holds event_lock
1574 * around the vblank disable, so no need for further locking.
1575 * The reference from drm_vblank_get() protects against
1576 * vblank disable from another source.
1578 if (!vblank
->enabled
) {
1583 ret
= drm_event_reserve_init_locked(dev
, file_priv
, &e
->base
,
1589 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1591 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1592 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1593 vblwait
->request
.sequence
= seq
+ 1;
1594 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1597 DRM_DEBUG("event on vblank count %d, current %d, crtc %u\n",
1598 vblwait
->request
.sequence
, seq
, pipe
);
1600 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1601 vblwait
->request
.sequence
);
1603 e
->event
.sequence
= vblwait
->request
.sequence
;
1604 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1605 drm_vblank_put(dev
, pipe
);
1606 send_vblank_event(dev
, e
, seq
, &now
);
1607 vblwait
->reply
.sequence
= seq
;
1609 /* drm_handle_vblank_events will call drm_vblank_put */
1610 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1611 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1614 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1619 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1622 drm_vblank_put(dev
, pipe
);
1629 * \param inode device inode.
1630 * \param file_priv DRM file private.
1631 * \param cmd command.
1632 * \param data user argument, pointing to a drm_wait_vblank structure.
1633 * \return zero on success or a negative number on failure.
1635 * This function enables the vblank interrupt on the pipe requested, then
1636 * sleeps waiting for the requested sequence number to occur, and drops
1637 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1638 * after a timeout with no further vblank waits scheduled).
1640 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1641 struct drm_file
*file_priv
)
1643 struct drm_vblank_crtc
*vblank
;
1644 union drm_wait_vblank
*vblwait
= data
;
1646 unsigned int flags
, seq
, pipe
, high_pipe
;
1648 if (!dev
->irq_enabled
)
1651 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1654 if (vblwait
->request
.type
&
1655 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1656 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1657 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1658 vblwait
->request
.type
,
1659 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1660 _DRM_VBLANK_HIGH_CRTC_MASK
));
1664 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1665 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1667 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1669 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1670 if (pipe
>= dev
->num_crtcs
)
1673 vblank
= &dev
->vblank
[pipe
];
1675 ret
= drm_vblank_get(dev
, pipe
);
1677 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1680 seq
= drm_vblank_count(dev
, pipe
);
1682 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1683 case _DRM_VBLANK_RELATIVE
:
1684 vblwait
->request
.sequence
+= seq
;
1685 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1686 case _DRM_VBLANK_ABSOLUTE
:
1693 if (flags
& _DRM_VBLANK_EVENT
) {
1694 /* must hold on to the vblank ref until the event fires
1695 * drm_vblank_put will be called asynchronously
1697 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1700 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1701 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1702 vblwait
->request
.sequence
= seq
+ 1;
1705 DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
1706 vblwait
->request
.sequence
, pipe
);
1707 vblank
->last_wait
= vblwait
->request
.sequence
;
1708 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1709 (((drm_vblank_count(dev
, pipe
) -
1710 vblwait
->request
.sequence
) <= (1 << 23)) ||
1712 !dev
->irq_enabled
));
1714 if (ret
!= -EINTR
) {
1717 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1718 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1719 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1721 DRM_DEBUG("returning %d to client\n",
1722 vblwait
->reply
.sequence
);
1724 DRM_DEBUG("vblank wait interrupted by signal\n");
1728 drm_vblank_put(dev
, pipe
);
1732 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1734 struct drm_pending_vblank_event
*e
, *t
;
1738 assert_spin_locked(&dev
->event_lock
);
1740 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1742 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1743 if (e
->pipe
!= pipe
)
1745 if ((seq
- e
->event
.sequence
) > (1<<23))
1748 DRM_DEBUG("vblank event on %d, current %d\n",
1749 e
->event
.sequence
, seq
);
1751 list_del(&e
->base
.link
);
1752 drm_vblank_put(dev
, pipe
);
1753 send_vblank_event(dev
, e
, seq
, &now
);
1756 trace_drm_vblank_event(pipe
, seq
);
1760 * drm_handle_vblank - handle a vblank event
1762 * @pipe: index of CRTC where this event occurred
1764 * Drivers should call this routine in their vblank interrupt handlers to
1765 * update the vblank counter and send any signals that may be pending.
1767 * This is the legacy version of drm_crtc_handle_vblank().
1769 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1771 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1772 unsigned long irqflags
;
1774 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1777 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1780 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1782 /* Need timestamp lock to prevent concurrent execution with
1783 * vblank enable/disable, as this would cause inconsistent
1784 * or corrupted timestamps and vblank counts.
1786 spin_lock(&dev
->vblank_time_lock
);
1788 /* Vblank irq handling disabled. Nothing to do. */
1789 if (!vblank
->enabled
) {
1790 spin_unlock(&dev
->vblank_time_lock
);
1791 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1795 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1797 spin_unlock(&dev
->vblank_time_lock
);
1799 wake_up(&vblank
->queue
);
1800 drm_handle_vblank_events(dev
, pipe
);
1802 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1806 EXPORT_SYMBOL(drm_handle_vblank
);
1809 * drm_crtc_handle_vblank - handle a vblank event
1810 * @crtc: where this event occurred
1812 * Drivers should call this routine in their vblank interrupt handlers to
1813 * update the vblank counter and send any signals that may be pending.
1815 * This is the native KMS version of drm_handle_vblank().
1818 * True if the event was successfully handled, false on failure.
1820 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1822 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1824 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1827 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1829 * @pipe: CRTC for which to read the counter
1831 * Drivers can plug this into the .get_vblank_counter() function if
1832 * there is no useable hardware frame counter available.
1837 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1841 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);