2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/slab.h>
41 #include <linux/export.h>
43 /* Access macro for slots in vblank timestamp ringbuffer. */
44 #define vblanktimestamp(dev, pipe, count) \
45 ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
47 /* Retry timestamp calculation up to 3 times to satisfy
48 * drm_timestamp_precision before giving up.
50 #define DRM_TIMESTAMP_MAXRETRIES 3
52 /* Threshold in nanoseconds for detection of redundant
53 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
55 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
58 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
59 struct timeval
*tvblank
, unsigned flags
);
61 unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
64 * Default to use monotonic timestamps for wait-for-vblank and page-flip
67 unsigned int drm_timestamp_monotonic
= 1;
69 int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
71 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
72 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
73 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
74 MODULE_PARM_DESC(vblankoffdelay
, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
75 MODULE_PARM_DESC(timestamp_precision_usec
, "Max. error on timestamps [usecs]");
76 MODULE_PARM_DESC(timestamp_monotonic
, "Use monotonic timestamps");
78 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
80 struct timeval
*t_vblank
, u32 last
)
82 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
85 assert_spin_locked(&dev
->vblank_time_lock
);
89 /* All writers hold the spinlock, but readers are serialized by
90 * the latching of vblank->count below.
92 tslot
= vblank
->count
+ vblank_count_inc
;
93 vblanktimestamp(dev
, pipe
, tslot
) = *t_vblank
;
96 * vblank timestamp updates are protected on the write side with
97 * vblank_time_lock, but on the read side done locklessly using a
98 * sequence-lock on the vblank counter. Ensure correct ordering using
99 * memory barrriers. We need the barrier both before and also after the
100 * counter update to synchronize with the next timestamp write.
101 * The read-side barriers for this are in drm_vblank_count_and_time.
104 vblank
->count
+= vblank_count_inc
;
109 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
111 * @pipe: index of CRTC for which to reset the timestamp
113 * Reset the stored timestamp for the current vblank count to correspond
114 * to the last vblank occurred.
116 * Only to be called from drm_vblank_on().
118 * Note: caller must hold dev->vbl_lock since this reads & writes
119 * device vblank fields.
121 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
125 struct timeval t_vblank
;
126 int count
= DRM_TIMESTAMP_MAXRETRIES
;
128 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
131 * sample the current counter to avoid random jumps
132 * when drm_vblank_enable() applies the diff
135 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
136 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
137 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
140 * Only reinitialize corresponding vblank timestamp if high-precision query
141 * available and didn't fail. Otherwise reinitialize delayed at next vblank
142 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
145 t_vblank
= (struct timeval
) {0, 0};
148 * +1 to make sure user will never see the same
149 * vblank counter value before and after a modeset
151 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
153 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
157 * drm_update_vblank_count - update the master vblank counter
159 * @pipe: counter to update
161 * Call back into the driver to update the appropriate vblank counter
162 * (specified by @pipe). Deal with wraparound, if it occurred, and
163 * update the last read value so we can deal with wraparound on the next
166 * Only necessary when going from off->on, to account for frames we
167 * didn't get an interrupt for.
169 * Note: caller must hold dev->vbl_lock since this reads & writes
170 * device vblank fields.
172 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
175 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
176 u32 cur_vblank
, diff
;
178 struct timeval t_vblank
;
179 int count
= DRM_TIMESTAMP_MAXRETRIES
;
180 int framedur_ns
= vblank
->framedur_ns
;
183 * Interrupts were disabled prior to this call, so deal with counter
185 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
186 * here if the register is small or we had vblank interrupts off for
189 * We repeat the hardware vblank counter & timestamp query until
190 * we get consistent results. This to prevent races between gpu
191 * updating its hardware counter while we are retrieving the
192 * corresponding vblank timestamp.
195 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
196 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
197 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
199 if (dev
->max_vblank_count
!= 0) {
200 /* trust the hw counter when it's around */
201 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
202 } else if (rc
&& framedur_ns
) {
203 const struct timeval
*t_old
;
206 t_old
= &vblanktimestamp(dev
, pipe
, vblank
->count
);
207 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
210 * Figure out how many vblanks we've missed based
211 * on the difference in the timestamps and the
212 * frame/field duration.
214 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
216 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
217 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
218 " diff_ns = %lld, framedur_ns = %d)\n",
219 pipe
, (long long) diff_ns
, framedur_ns
);
221 /* some kind of default for drivers w/o accurate vbl timestamping */
222 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
226 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
227 * interval? If so then vblank irqs keep running and it will likely
228 * happen that the hardware vblank counter is not trustworthy as it
229 * might reset at some point in that interval and vblank timestamps
230 * are not trustworthy either in that interval. Iow. this can result
231 * in a bogus diff >> 1 which must be avoided as it would cause
232 * random large forward jumps of the software vblank counter.
234 if (diff
> 1 && (vblank
->inmodeset
& 0x2)) {
235 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
236 " due to pre-modeset.\n", pipe
, diff
);
241 * FIMXE: Need to replace this hack with proper seqlocks.
243 * Restrict the bump of the software vblank counter to a safe maximum
244 * value of +1 whenever there is the possibility that concurrent readers
245 * of vblank timestamps could be active at the moment, as the current
246 * implementation of the timestamp caching and updating is not safe
247 * against concurrent readers for calls to store_vblank() with a bump
248 * of anything but +1. A bump != 1 would very likely return corrupted
249 * timestamps to userspace, because the same slot in the cache could
250 * be concurrently written by store_vblank() and read by one of those
251 * readers without the read-retry logic detecting the collision.
253 * Concurrent readers can exist when we are called from the
254 * drm_vblank_off() or drm_vblank_on() functions and other non-vblank-
255 * irq callers. However, all those calls to us are happening with the
256 * vbl_lock locked to prevent drm_vblank_get(), so the vblank refcount
257 * can't increase while we are executing. Therefore a zero refcount at
258 * this point is safe for arbitrary counter bumps if we are called
259 * outside vblank irq, a non-zero count is not 100% safe. Unfortunately
260 * we must also accept a refcount of 1, as whenever we are called from
261 * drm_vblank_get() -> drm_vblank_enable() the refcount will be 1 and
262 * we must let that one pass through in order to not lose vblank counts
263 * during vblank irq off - which would completely defeat the whole
264 * point of this routine.
266 * Whenever we are called from vblank irq, we have to assume concurrent
267 * readers exist or can show up any time during our execution, even if
268 * the refcount is currently zero, as vblank irqs are usually only
269 * enabled due to the presence of readers, and because when we are called
270 * from vblank irq we can't hold the vbl_lock to protect us from sudden
271 * bumps in vblank refcount. Therefore also restrict bumps to +1 when
272 * called from vblank irq.
274 if ((diff
> 1) && (atomic_read(&vblank
->refcount
) > 1 ||
275 (flags
& DRM_CALLED_FROM_VBLIRQ
))) {
276 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u "
277 "refcount %u, vblirq %u\n", pipe
, diff
,
278 atomic_read(&vblank
->refcount
),
279 (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0);
283 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
284 " current=%u, diff=%u, hw=%u hw_last=%u\n",
285 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
288 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
293 * Only reinitialize corresponding vblank timestamp if high-precision query
294 * available and didn't fail, or we were called from the vblank interrupt.
295 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
296 * for now, to mark the vblanktimestamp as invalid.
298 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
299 t_vblank
= (struct timeval
) {0, 0};
301 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
305 * Disable vblank irq's on crtc, make sure that last vblank count
306 * of hardware and corresponding consistent software vblank counter
307 * are preserved, even if there are any spurious vblank irq's after
310 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
312 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
313 unsigned long irqflags
;
315 /* Prevent vblank irq processing while disabling vblank irqs,
316 * so no updates of timestamps or count can happen after we've
317 * disabled. Needed to prevent races in case of delayed irq's.
319 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
322 * Only disable vblank interrupts if they're enabled. This avoids
323 * calling the ->disable_vblank() operation in atomic context with the
324 * hardware potentially runtime suspended.
326 if (vblank
->enabled
) {
327 dev
->driver
->disable_vblank(dev
, pipe
);
328 vblank
->enabled
= false;
332 * Always update the count and timestamp to maintain the
333 * appearance that the counter has been ticking all along until
334 * this time. This makes the count account for the entire time
335 * between drm_vblank_on() and drm_vblank_off().
337 drm_update_vblank_count(dev
, pipe
, 0);
339 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
342 static void vblank_disable_fn(unsigned long arg
)
344 struct drm_vblank_crtc
*vblank
= (void *)arg
;
345 struct drm_device
*dev
= vblank
->dev
;
346 unsigned int pipe
= vblank
->pipe
;
347 unsigned long irqflags
;
349 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
350 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
351 DRM_DEBUG_VBLANK("disabling vblank on crtc %u\n", pipe
);
352 vblank_disable_and_save(dev
, pipe
);
354 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
358 * drm_vblank_cleanup - cleanup vblank support
361 * This function cleans up any resources allocated in drm_vblank_init.
363 void drm_vblank_cleanup(struct drm_device
*dev
)
367 /* Bail if the driver didn't call drm_vblank_init() */
368 if (dev
->num_crtcs
== 0)
371 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
372 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
374 WARN_ON(vblank
->enabled
&&
375 drm_core_check_feature(dev
, DRIVER_MODESET
));
377 del_timer_sync(&vblank
->disable_timer
);
384 EXPORT_SYMBOL(drm_vblank_cleanup
);
387 * drm_vblank_init - initialize vblank support
389 * @num_crtcs: number of CRTCs supported by @dev
391 * This function initializes vblank support for @num_crtcs display pipelines.
394 * Zero on success or a negative error code on failure.
396 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
401 lockinit(&dev
->vbl_lock
, "drmvbl", 0, LK_CANRECURSE
);
402 lockinit(&dev
->vblank_time_lock
, "drmvtl", 0, LK_CANRECURSE
);
404 dev
->num_crtcs
= num_crtcs
;
406 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
410 for (i
= 0; i
< num_crtcs
; i
++) {
411 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
415 init_waitqueue_head(&vblank
->queue
);
416 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
417 (unsigned long)vblank
);
420 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
422 /* Driver specific high-precision vblank timestamping supported? */
423 if (dev
->driver
->get_vblank_timestamp
)
424 DRM_INFO("Driver supports precise vblank timestamp query.\n");
426 DRM_INFO("No driver support for vblank timestamp query.\n");
428 /* Must have precise timestamping for reliable vblank instant disable */
429 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
430 dev
->vblank_disable_immediate
= false;
431 DRM_INFO("Setting vblank_disable_immediate to false because "
432 "get_vblank_timestamp == NULL\n");
441 EXPORT_SYMBOL(drm_vblank_init
);
444 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
446 struct drm_device
*dev
= cookie
;
448 if (dev
->driver
->vgaarb_irq
) {
449 dev
->driver
->vgaarb_irq(dev
, state
);
453 if (!dev
->irq_enabled
)
457 if (dev
->driver
->irq_uninstall
)
458 dev
->driver
->irq_uninstall(dev
);
460 if (dev
->driver
->irq_preinstall
)
461 dev
->driver
->irq_preinstall(dev
);
462 if (dev
->driver
->irq_postinstall
)
463 dev
->driver
->irq_postinstall(dev
);
469 * drm_irq_install - install IRQ handler
471 * @irq: IRQ number to install the handler for
473 * Initializes the IRQ related data. Installs the handler, calling the driver
474 * irq_preinstall() and irq_postinstall() functions before and after the
477 * This is the simplified helper interface provided for drivers with no special
478 * needs. Drivers which need to install interrupt handlers for multiple
479 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
480 * that vblank interrupts are available.
483 * Zero on success or a negative error code on failure.
485 int drm_irq_install(struct drm_device
*dev
, int irq
)
489 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
495 /* Driver must have been initialized */
496 if (!dev
->dev_private
)
499 if (dev
->irq_enabled
)
501 dev
->irq_enabled
= true;
503 DRM_DEBUG("irq=%d\n", irq
);
505 /* Before installing handler */
506 if (dev
->driver
->irq_preinstall
)
507 dev
->driver
->irq_preinstall(dev
);
509 /* Install handler */
510 ret
= -bus_setup_intr(dev
->dev
->bsddev
, dev
->irqr
, INTR_MPSAFE
,
511 dev
->driver
->irq_handler
, dev
, &dev
->irqh
, &dev
->irq_lock
);
514 dev
->irq_enabled
= false;
518 /* After installing handler */
519 if (dev
->driver
->irq_postinstall
)
520 ret
= dev
->driver
->irq_postinstall(dev
);
523 dev
->irq_enabled
= false;
524 bus_teardown_intr(dev
->dev
->bsddev
, dev
->irqr
, dev
->irqh
);
531 EXPORT_SYMBOL(drm_irq_install
);
534 * drm_irq_uninstall - uninstall the IRQ handler
537 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
538 * This should only be called by drivers which used drm_irq_install() to set up
539 * their interrupt handler. Other drivers must only reset
540 * drm_device->irq_enabled to false.
542 * Note that for kernel modesetting drivers it is a bug if this function fails.
543 * The sanity checks are only to catch buggy user modesetting drivers which call
544 * the same function through an ioctl.
547 * Zero on success or a negative error code on failure.
549 int drm_irq_uninstall(struct drm_device
*dev
)
551 unsigned long irqflags
;
555 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
558 irq_enabled
= dev
->irq_enabled
;
559 dev
->irq_enabled
= false;
562 * Wake up any waiters so they don't hang. This is just to paper over
563 * isssues for UMS drivers which aren't in full control of their
564 * vblank/irq handling. KMS drivers must ensure that vblanks are all
565 * disabled when uninstalling the irq handler.
567 if (dev
->num_crtcs
) {
568 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
569 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
570 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
572 if (!vblank
->enabled
)
575 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
577 vblank_disable_and_save(dev
, i
);
578 wake_up(&vblank
->queue
);
580 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
586 DRM_DEBUG("irq=%d\n", dev
->irq
);
588 if (dev
->driver
->irq_uninstall
)
589 dev
->driver
->irq_uninstall(dev
);
591 bus_teardown_intr(dev
->dev
->bsddev
, dev
->irqr
, dev
->irqh
);
595 EXPORT_SYMBOL(drm_irq_uninstall
);
600 * \param inode device inode.
601 * \param file_priv DRM file private.
602 * \param cmd command.
603 * \param arg user argument, pointing to a drm_control structure.
604 * \return zero on success or a negative number on failure.
606 * Calls irq_install() or irq_uninstall() according to \p arg.
608 int drm_control(struct drm_device
*dev
, void *data
,
609 struct drm_file
*file_priv
)
611 struct drm_control
*ctl
= data
;
614 /* if we haven't irq we fallback for compatibility reasons -
615 * this used to be a separate function in drm_dma.h
618 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
620 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
622 /* UMS was only ever support on pci devices. */
623 if (WARN_ON(!dev
->pdev
))
627 case DRM_INST_HANDLER
:
630 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
633 mutex_lock(&dev
->struct_mutex
);
634 ret
= drm_irq_install(dev
, irq
);
635 mutex_unlock(&dev
->struct_mutex
);
638 case DRM_UNINST_HANDLER
:
639 mutex_lock(&dev
->struct_mutex
);
640 ret
= drm_irq_uninstall(dev
);
641 mutex_unlock(&dev
->struct_mutex
);
650 * drm_calc_timestamping_constants - calculate vblank timestamp constants
651 * @crtc: drm_crtc whose timestamp constants should be updated.
652 * @mode: display mode containing the scanout timings
654 * Calculate and store various constants which are later
655 * needed by vblank and swap-completion timestamping, e.g,
656 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
657 * derived from CRTC's true scanout timing, so they take
658 * things like panel scaling or other adjustments into account.
660 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
661 const struct drm_display_mode
*mode
)
663 struct drm_device
*dev
= crtc
->dev
;
664 unsigned int pipe
= drm_crtc_index(crtc
);
665 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
666 int linedur_ns
= 0, framedur_ns
= 0;
667 int dotclock
= mode
->crtc_clock
;
672 if (WARN_ON(pipe
>= dev
->num_crtcs
))
675 /* Valid dotclock? */
677 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
680 * Convert scanline length in pixels and video
681 * dot clock to line duration and frame duration
684 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
685 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
688 * Fields of interlaced scanout modes are only half a frame duration.
690 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
693 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
696 vblank
->linedur_ns
= linedur_ns
;
697 vblank
->framedur_ns
= framedur_ns
;
699 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
700 crtc
->base
.id
, mode
->crtc_htotal
,
701 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
702 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
703 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
705 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
708 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
710 * @pipe: index of CRTC whose vblank timestamp to retrieve
711 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
712 * On return contains true maximum error of timestamp
713 * @vblank_time: Pointer to struct timeval which should receive the timestamp
714 * @flags: Flags to pass to driver:
716 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
717 * @mode: mode which defines the scanout timings
719 * Implements calculation of exact vblank timestamps from given drm_display_mode
720 * timings and current video scanout position of a CRTC. This can be called from
721 * within get_vblank_timestamp() implementation of a kms driver to implement the
722 * actual timestamping.
724 * Should return timestamps conforming to the OML_sync_control OpenML
725 * extension specification. The timestamp corresponds to the end of
726 * the vblank interval, aka start of scanout of topmost-leftmost display
727 * pixel in the following video frame.
729 * Requires support for optional dev->driver->get_scanout_position()
730 * in kms driver, plus a bit of setup code to provide a drm_display_mode
731 * that corresponds to the true scanout timing.
733 * The current implementation only handles standard video modes. It
734 * returns as no operation if a doublescan or interlaced video mode is
735 * active. Higher level code is expected to handle this.
738 * Negative value on error, failure or if not supported in current
741 * -EINVAL - Invalid CRTC.
742 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
743 * -ENOTSUPP - Function not supported in current display mode.
744 * -EIO - Failed, e.g., due to failed scanout position query.
746 * Returns or'ed positive status flags on success:
748 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
749 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
752 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
755 struct timeval
*vblank_time
,
757 const struct drm_display_mode
*mode
)
759 struct timeval tv_etime
;
760 ktime_t stime
, etime
;
761 unsigned int vbl_status
;
762 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
764 int delta_ns
, duration_ns
;
766 if (pipe
>= dev
->num_crtcs
) {
767 DRM_ERROR("Invalid crtc %u\n", pipe
);
771 /* Scanout position query not supported? Should not happen. */
772 if (!dev
->driver
->get_scanout_position
) {
773 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
777 /* If mode timing undefined, just return as no-op:
778 * Happens during initial modesetting of a crtc.
780 if (mode
->crtc_clock
== 0) {
781 DRM_DEBUG_VBLANK("crtc %u: Noop due to uninitialized mode.\n", pipe
);
785 /* Get current scanout position with system timestamp.
786 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
787 * if single query takes longer than max_error nanoseconds.
789 * This guarantees a tight bound on maximum error if
790 * code gets preempted or delayed for some reason.
792 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
794 * Get vertical and horizontal scanout position vpos, hpos,
795 * and bounding timestamps stime, etime, pre/post query.
797 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
802 /* Return as no-op if scanout query unsupported or failed. */
803 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
804 DRM_DEBUG_VBLANK("crtc %u : scanoutpos query failed [0x%x].\n",
809 /* Compute uncertainty in timestamp of scanout position query. */
810 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
812 /* Accept result with < max_error nsecs timing uncertainty. */
813 if (duration_ns
<= *max_error
)
817 /* Noisy system timing? */
818 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
819 DRM_DEBUG_VBLANK("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
820 pipe
, duration_ns
/1000, *max_error
/1000, i
);
823 /* Return upper bound of timestamp precision error. */
824 *max_error
= duration_ns
;
826 /* Check if in vblank area:
827 * vpos is >=0 in video scanout area, but negative
828 * within vblank area, counting down the number of lines until
831 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
832 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
834 /* Convert scanout position into elapsed time at raw_time query
835 * since start of scanout at first display scanline. delta_ns
836 * can be negative if start of scanout hasn't happened yet.
838 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
841 if (!drm_timestamp_monotonic
)
842 etime
= ktime_mono_to_real(etime
);
844 /* save this only for debugging purposes */
845 tv_etime
= ktime_to_timeval(etime
);
846 /* Subtract time delta from raw timestamp to get final
847 * vblank_time timestamp for end of vblank.
849 etime
= ktime_sub_ns(etime
, delta_ns
);
850 *vblank_time
= ktime_to_timeval(etime
);
852 DRM_DEBUG_VBLANK("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
853 pipe
, vbl_status
, hpos
, vpos
,
854 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
855 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
856 duration_ns
/1000, i
);
860 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
862 static struct timeval
get_drm_timestamp(void)
866 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
867 return ktime_to_timeval(now
);
871 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
874 * @pipe: index of CRTC whose vblank timestamp to retrieve
875 * @tvblank: Pointer to target struct timeval which should receive the timestamp
876 * @flags: Flags to pass to driver:
878 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
880 * Fetches the system timestamp corresponding to the time of the most recent
881 * vblank interval on specified CRTC. May call into kms-driver to
882 * compute the timestamp with a high-precision GPU specific method.
884 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
885 * call, i.e., it isn't very precisely locked to the true vblank.
888 * True if timestamp is considered to be very precise, false otherwise.
891 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
892 struct timeval
*tvblank
, unsigned flags
)
896 /* Define requested maximum error on timestamps (nanoseconds). */
897 int max_error
= (int) drm_timestamp_precision
* 1000;
899 /* Query driver if possible and precision timestamping enabled. */
900 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
901 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
907 /* GPU high precision timestamp query unsupported or failed.
908 * Return current monotonic/gettimeofday timestamp as best estimate.
910 *tvblank
= get_drm_timestamp();
916 * drm_vblank_count - retrieve "cooked" vblank counter value
918 * @pipe: index of CRTC for which to retrieve the counter
920 * Fetches the "cooked" vblank count value that represents the number of
921 * vblank events since the system was booted, including lost events due to
922 * modesetting activity.
924 * This is the legacy version of drm_crtc_vblank_count().
927 * The software vblank counter.
929 u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
931 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
933 if (WARN_ON(pipe
>= dev
->num_crtcs
))
936 return vblank
->count
;
938 EXPORT_SYMBOL(drm_vblank_count
);
941 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
942 * @crtc: which counter to retrieve
944 * Fetches the "cooked" vblank count value that represents the number of
945 * vblank events since the system was booted, including lost events due to
946 * modesetting activity.
948 * This is the native KMS version of drm_vblank_count().
951 * The software vblank counter.
953 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
955 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
957 EXPORT_SYMBOL(drm_crtc_vblank_count
);
960 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
961 * system timestamp corresponding to that vblank counter value.
963 * @pipe: index of CRTC whose counter to retrieve
964 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
966 * Fetches the "cooked" vblank count value that represents the number of
967 * vblank events since the system was booted, including lost events due to
968 * modesetting activity. Returns corresponding system timestamp of the time
969 * of the vblank interval that corresponds to the current vblank counter value.
971 * This is the legacy version of drm_crtc_vblank_count_and_time().
973 u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
974 struct timeval
*vblanktime
)
976 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
977 int count
= DRM_TIMESTAMP_MAXRETRIES
;
980 vblanktime
->tv_sec
= 0; /* silence gcc warning */
981 vblanktime
->tv_usec
= 0; /* silence gcc warning */
982 if (WARN_ON(pipe
>= dev
->num_crtcs
))
986 * Vblank timestamps are read lockless. To ensure consistency the vblank
987 * counter is rechecked and ordering is ensured using memory barriers.
988 * This works like a seqlock. The write-side barriers are in store_vblank.
991 cur_vblank
= vblank
->count
;
993 *vblanktime
= vblanktimestamp(dev
, pipe
, cur_vblank
);
995 } while (cur_vblank
!= vblank
->count
&& --count
> 0);
999 EXPORT_SYMBOL(drm_vblank_count_and_time
);
1002 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
1003 * and the system timestamp corresponding to that vblank counter value
1004 * @crtc: which counter to retrieve
1005 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
1007 * Fetches the "cooked" vblank count value that represents the number of
1008 * vblank events since the system was booted, including lost events due to
1009 * modesetting activity. Returns corresponding system timestamp of the time
1010 * of the vblank interval that corresponds to the current vblank counter value.
1012 * This is the native KMS version of drm_vblank_count_and_time().
1014 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
1015 struct timeval
*vblanktime
)
1017 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
1020 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
1022 static void send_vblank_event(struct drm_device
*dev
,
1023 struct drm_pending_vblank_event
*e
,
1024 unsigned long seq
, struct timeval
*now
)
1026 e
->event
.sequence
= seq
;
1027 e
->event
.tv_sec
= now
->tv_sec
;
1028 e
->event
.tv_usec
= now
->tv_usec
;
1030 drm_send_event_locked(dev
, &e
->base
);
1032 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1037 * drm_arm_vblank_event - arm vblank event after pageflip
1040 * @e: the event to prepare to send
1042 * A lot of drivers need to generate vblank events for the very next vblank
1043 * interrupt. For example when the page flip interrupt happens when the page
1044 * flip gets armed, but not when it actually executes within the next vblank
1045 * period. This helper function implements exactly the required vblank arming
1048 * Caller must hold event lock. Caller must also hold a vblank reference for
1049 * the event @e, which will be dropped when the next vblank arrives.
1051 * This is the legacy version of drm_crtc_arm_vblank_event().
1053 void drm_arm_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1054 struct drm_pending_vblank_event
*e
)
1056 assert_spin_locked(&dev
->event_lock
);
1059 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1060 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1062 EXPORT_SYMBOL(drm_arm_vblank_event
);
1065 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1066 * @crtc: the source CRTC of the vblank event
1067 * @e: the event to send
1069 * A lot of drivers need to generate vblank events for the very next vblank
1070 * interrupt. For example when the page flip interrupt happens when the page
1071 * flip gets armed, but not when it actually executes within the next vblank
1072 * period. This helper function implements exactly the required vblank arming
1075 * Caller must hold event lock. Caller must also hold a vblank reference for
1076 * the event @e, which will be dropped when the next vblank arrives.
1078 * This is the native KMS version of drm_arm_vblank_event().
1080 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1081 struct drm_pending_vblank_event
*e
)
1083 drm_arm_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1085 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1088 * drm_send_vblank_event - helper to send vblank event after pageflip
1091 * @e: the event to send
1093 * Updates sequence # and timestamp on event, and sends it to userspace.
1094 * Caller must hold event lock.
1096 * This is the legacy version of drm_crtc_send_vblank_event().
1098 void drm_send_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1099 struct drm_pending_vblank_event
*e
)
1104 if (dev
->num_crtcs
> 0) {
1105 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1109 now
= get_drm_timestamp();
1112 send_vblank_event(dev
, e
, seq
, &now
);
1114 EXPORT_SYMBOL(drm_send_vblank_event
);
1117 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1118 * @crtc: the source CRTC of the vblank event
1119 * @e: the event to send
1121 * Updates sequence # and timestamp on event, and sends it to userspace.
1122 * Caller must hold event lock.
1124 * This is the native KMS version of drm_send_vblank_event().
1126 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1127 struct drm_pending_vblank_event
*e
)
1129 drm_send_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1131 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1134 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1139 * Zero on success or a negative error code on failure.
1141 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1143 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1146 assert_spin_locked(&dev
->vbl_lock
);
1148 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1150 if (!vblank
->enabled
) {
1152 * Enable vblank irqs under vblank_time_lock protection.
1153 * All vblank count & timestamp updates are held off
1154 * until we are done reinitializing master counter and
1155 * timestamps. Filtercode in drm_handle_vblank() will
1156 * prevent double-accounting of same vblank interval.
1158 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1159 DRM_DEBUG_VBLANK("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1161 atomic_dec(&vblank
->refcount
);
1163 vblank
->enabled
= true;
1164 drm_update_vblank_count(dev
, pipe
, 0);
1168 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1174 * drm_vblank_get - get a reference count on vblank events
1176 * @pipe: index of CRTC to own
1178 * Acquire a reference count on vblank events to avoid having them disabled
1181 * This is the legacy version of drm_crtc_vblank_get().
1184 * Zero on success or a negative error code on failure.
1186 int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1188 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1189 unsigned long irqflags
;
1192 if (!dev
->num_crtcs
)
1195 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1198 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1199 /* Going from 0->1 means we have to enable interrupts again */
1200 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1201 ret
= drm_vblank_enable(dev
, pipe
);
1203 if (!vblank
->enabled
) {
1204 atomic_dec(&vblank
->refcount
);
1208 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1212 EXPORT_SYMBOL(drm_vblank_get
);
1215 * drm_crtc_vblank_get - get a reference count on vblank events
1216 * @crtc: which CRTC to own
1218 * Acquire a reference count on vblank events to avoid having them disabled
1221 * This is the native kms version of drm_vblank_get().
1224 * Zero on success or a negative error code on failure.
1226 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1228 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1230 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1233 * drm_vblank_put - release ownership of vblank events
1235 * @pipe: index of CRTC to release
1237 * Release ownership of a given vblank counter, turning off interrupts
1238 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1240 * This is the legacy version of drm_crtc_vblank_put().
1242 void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1244 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1246 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1249 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1252 /* Last user schedules interrupt disable */
1253 if (atomic_dec_and_test(&vblank
->refcount
)) {
1254 if (drm_vblank_offdelay
== 0)
1256 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1257 vblank_disable_fn((unsigned long)vblank
);
1259 mod_timer(&vblank
->disable_timer
,
1260 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1263 EXPORT_SYMBOL(drm_vblank_put
);
1266 * drm_crtc_vblank_put - give up ownership of vblank events
1267 * @crtc: which counter to give up
1269 * Release ownership of a given vblank counter, turning off interrupts
1270 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1272 * This is the native kms version of drm_vblank_put().
1274 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1276 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1278 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1281 * drm_wait_one_vblank - wait for one vblank
1285 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1286 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1287 * due to lack of driver support or because the crtc is off.
1289 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1291 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1295 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1298 ret
= drm_vblank_get(dev
, pipe
);
1299 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1302 last
= drm_vblank_count(dev
, pipe
);
1304 ret
= wait_event_timeout(vblank
->queue
,
1305 last
!= drm_vblank_count(dev
, pipe
),
1306 msecs_to_jiffies(100));
1308 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1310 drm_vblank_put(dev
, pipe
);
1312 EXPORT_SYMBOL(drm_wait_one_vblank
);
1315 * drm_crtc_wait_one_vblank - wait for one vblank
1318 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1319 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1320 * due to lack of driver support or because the crtc is off.
1322 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1324 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1326 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1329 * drm_vblank_off - disable vblank events on a CRTC
1333 * Drivers can use this function to shut down the vblank interrupt handling when
1334 * disabling a crtc. This function ensures that the latest vblank frame count is
1335 * stored so that drm_vblank_on() can restore it again.
1337 * Drivers must use this function when the hardware vblank counter can get
1338 * reset, e.g. when suspending.
1340 * This is the legacy version of drm_crtc_vblank_off().
1342 void drm_vblank_off(struct drm_device
*dev
, unsigned int pipe
)
1344 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1345 struct drm_pending_vblank_event
*e
, *t
;
1347 unsigned long irqflags
;
1350 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1353 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1355 lockmgr(&dev
->vbl_lock
, LK_EXCLUSIVE
);
1356 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1357 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1359 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1360 if (drm_core_check_feature(dev
, DRIVER_ATOMIC
) || !vblank
->inmodeset
)
1361 vblank_disable_and_save(dev
, pipe
);
1363 wake_up(&vblank
->queue
);
1366 * Prevent subsequent drm_vblank_get() from re-enabling
1367 * the vblank interrupt by bumping the refcount.
1369 if (!vblank
->inmodeset
) {
1370 atomic_inc(&vblank
->refcount
);
1371 vblank
->inmodeset
= 1;
1373 lockmgr(&dev
->vbl_lock
, LK_RELEASE
);
1375 /* Send any queued vblank events, lest the natives grow disquiet */
1376 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1378 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1379 if (e
->pipe
!= pipe
)
1381 DRM_DEBUG_VBLANK("Sending premature vblank event on disable: \
1382 wanted %d, current %d\n",
1383 e
->event
.sequence
, seq
);
1384 list_del(&e
->base
.link
);
1385 drm_vblank_put(dev
, pipe
);
1386 send_vblank_event(dev
, e
, seq
, &now
);
1388 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1390 EXPORT_SYMBOL(drm_vblank_off
);
1393 * drm_crtc_vblank_off - disable vblank events on a CRTC
1394 * @crtc: CRTC in question
1396 * Drivers can use this function to shut down the vblank interrupt handling when
1397 * disabling a crtc. This function ensures that the latest vblank frame count is
1398 * stored so that drm_vblank_on can restore it again.
1400 * Drivers must use this function when the hardware vblank counter can get
1401 * reset, e.g. when suspending.
1403 * This is the native kms version of drm_vblank_off().
1405 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1407 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1409 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1412 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1413 * @crtc: CRTC in question
1415 * Drivers can use this function to reset the vblank state to off at load time.
1416 * Drivers should use this together with the drm_crtc_vblank_off() and
1417 * drm_crtc_vblank_on() functions. The difference compared to
1418 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1419 * and hence doesn't need to call any driver hooks.
1421 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1423 struct drm_device
*dev
= crtc
->dev
;
1424 unsigned long irqflags
;
1425 unsigned int pipe
= drm_crtc_index(crtc
);
1426 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1428 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1430 * Prevent subsequent drm_vblank_get() from enabling the vblank
1431 * interrupt by bumping the refcount.
1433 if (!vblank
->inmodeset
) {
1434 atomic_inc(&vblank
->refcount
);
1435 vblank
->inmodeset
= 1;
1437 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1439 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1441 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1444 * drm_vblank_on - enable vblank events on a CRTC
1448 * This functions restores the vblank interrupt state captured with
1449 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1450 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1451 * in driver load code to reflect the current hardware state of the crtc.
1453 * This is the legacy version of drm_crtc_vblank_on().
1455 void drm_vblank_on(struct drm_device
*dev
, unsigned int pipe
)
1457 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1458 unsigned long irqflags
;
1460 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1463 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1464 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1465 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1467 /* Drop our private "prevent drm_vblank_get" refcount */
1468 if (vblank
->inmodeset
) {
1469 atomic_dec(&vblank
->refcount
);
1470 vblank
->inmodeset
= 0;
1473 drm_reset_vblank_timestamp(dev
, pipe
);
1476 * re-enable interrupts if there are users left, or the
1477 * user wishes vblank interrupts to be enabled all the time.
1479 if (atomic_read(&vblank
->refcount
) != 0 || drm_vblank_offdelay
== 0)
1480 WARN_ON(drm_vblank_enable(dev
, pipe
));
1481 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1483 EXPORT_SYMBOL(drm_vblank_on
);
1486 * drm_crtc_vblank_on - enable vblank events on a CRTC
1487 * @crtc: CRTC in question
1489 * This functions restores the vblank interrupt state captured with
1490 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1491 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1492 * in driver load code to reflect the current hardware state of the crtc.
1494 * This is the native kms version of drm_vblank_on().
1496 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1498 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1500 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1503 * drm_vblank_pre_modeset - account for vblanks across mode sets
1507 * Account for vblank events across mode setting events, which will likely
1508 * reset the hardware frame counter.
1510 * This is done by grabbing a temporary vblank reference to ensure that the
1511 * vblank interrupt keeps running across the modeset sequence. With this the
1512 * software-side vblank frame counting will ensure that there are no jumps or
1515 * Unfortunately this approach is racy and also doesn't work when the vblank
1516 * interrupt stops running, e.g. across system suspend resume. It is therefore
1517 * highly recommended that drivers use the newer drm_vblank_off() and
1518 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1519 * using "cooked" software vblank frame counters and not relying on any hardware
1522 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1525 void drm_vblank_pre_modeset(struct drm_device
*dev
, unsigned int pipe
)
1527 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1529 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1530 if (!dev
->num_crtcs
)
1533 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1537 * To avoid all the problems that might happen if interrupts
1538 * were enabled/disabled around or between these calls, we just
1539 * have the kernel take a reference on the CRTC (just once though
1540 * to avoid corrupting the count if multiple, mismatch calls occur),
1541 * so that interrupts remain enabled in the interim.
1543 if (!vblank
->inmodeset
) {
1544 vblank
->inmodeset
= 0x1;
1545 if (drm_vblank_get(dev
, pipe
) == 0)
1546 vblank
->inmodeset
|= 0x2;
1549 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1552 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1556 * This function again drops the temporary vblank reference acquired in
1557 * drm_vblank_pre_modeset.
1559 void drm_vblank_post_modeset(struct drm_device
*dev
, unsigned int pipe
)
1561 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1562 unsigned long irqflags
;
1564 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1565 if (!dev
->num_crtcs
)
1568 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1571 if (vblank
->inmodeset
) {
1572 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1573 drm_reset_vblank_timestamp(dev
, pipe
);
1574 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1576 if (vblank
->inmodeset
& 0x2)
1577 drm_vblank_put(dev
, pipe
);
1579 vblank
->inmodeset
= 0;
1582 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1585 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1586 * @DRM_IOCTL_ARGS: standard ioctl arguments
1588 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1589 * ioctls around modesetting so that any lost vblank events are accounted for.
1591 * Generally the counter will reset across mode sets. If interrupts are
1592 * enabled around this call, we don't have to do anything since the counter
1593 * will have already been incremented.
1595 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1596 struct drm_file
*file_priv
)
1598 struct drm_modeset_ctl
*modeset
= data
;
1601 /* If drm_vblank_init() hasn't been called yet, just no-op */
1602 if (!dev
->num_crtcs
)
1605 /* KMS drivers handle this internally */
1606 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1609 pipe
= modeset
->crtc
;
1610 if (pipe
>= dev
->num_crtcs
)
1613 switch (modeset
->cmd
) {
1614 case _DRM_PRE_MODESET
:
1615 drm_vblank_pre_modeset(dev
, pipe
);
1617 case _DRM_POST_MODESET
:
1618 drm_vblank_post_modeset(dev
, pipe
);
1627 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1628 union drm_wait_vblank
*vblwait
,
1629 struct drm_file
*file_priv
)
1631 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1632 struct drm_pending_vblank_event
*e
;
1634 unsigned long flags
;
1638 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1645 e
->base
.pid
= curproc
->p_pid
;
1646 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1647 e
->event
.base
.length
= sizeof(e
->event
);
1648 e
->event
.user_data
= vblwait
->request
.signal
;
1650 spin_lock_irqsave(&dev
->event_lock
, flags
);
1653 * drm_vblank_off() might have been called after we called
1654 * drm_vblank_get(). drm_vblank_off() holds event_lock
1655 * around the vblank disable, so no need for further locking.
1656 * The reference from drm_vblank_get() protects against
1657 * vblank disable from another source.
1659 if (!vblank
->enabled
) {
1664 ret
= drm_event_reserve_init_locked(dev
, file_priv
, &e
->base
,
1670 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1672 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1673 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1674 vblwait
->request
.sequence
= seq
+ 1;
1675 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1678 DRM_DEBUG_VBLANK("event on vblank count %d, current %d, crtc %u\n",
1679 vblwait
->request
.sequence
, seq
, pipe
);
1681 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1682 vblwait
->request
.sequence
);
1684 e
->event
.sequence
= vblwait
->request
.sequence
;
1685 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1686 drm_vblank_put(dev
, pipe
);
1687 send_vblank_event(dev
, e
, seq
, &now
);
1688 vblwait
->reply
.sequence
= seq
;
1690 /* drm_handle_vblank_events will call drm_vblank_put */
1691 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1692 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1695 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1700 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1703 drm_vblank_put(dev
, pipe
);
1710 * \param inode device inode.
1711 * \param file_priv DRM file private.
1712 * \param cmd command.
1713 * \param data user argument, pointing to a drm_wait_vblank structure.
1714 * \return zero on success or a negative number on failure.
1716 * This function enables the vblank interrupt on the pipe requested, then
1717 * sleeps waiting for the requested sequence number to occur, and drops
1718 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1719 * after a timeout with no further vblank waits scheduled).
1721 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1722 struct drm_file
*file_priv
)
1724 struct drm_vblank_crtc
*vblank
;
1725 union drm_wait_vblank
*vblwait
= data
;
1727 unsigned int flags
, seq
, pipe
, high_pipe
;
1729 if (!dev
->irq_enabled
)
1732 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1735 if (vblwait
->request
.type
&
1736 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1737 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1738 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1739 vblwait
->request
.type
,
1740 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1741 _DRM_VBLANK_HIGH_CRTC_MASK
));
1745 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1746 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1748 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1750 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1751 if (pipe
>= dev
->num_crtcs
)
1754 vblank
= &dev
->vblank
[pipe
];
1756 ret
= drm_vblank_get(dev
, pipe
);
1758 DRM_DEBUG_VBLANK("failed to acquire vblank counter, %d\n", ret
);
1761 seq
= drm_vblank_count(dev
, pipe
);
1763 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1764 case _DRM_VBLANK_RELATIVE
:
1765 vblwait
->request
.sequence
+= seq
;
1766 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1767 case _DRM_VBLANK_ABSOLUTE
:
1774 if (flags
& _DRM_VBLANK_EVENT
) {
1775 /* must hold on to the vblank ref until the event fires
1776 * drm_vblank_put will be called asynchronously
1778 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1781 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1782 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1783 vblwait
->request
.sequence
= seq
+ 1;
1786 DRM_DEBUG_VBLANK("waiting on vblank count %d, crtc %u\n",
1787 vblwait
->request
.sequence
, pipe
);
1788 vblank
->last_wait
= vblwait
->request
.sequence
;
1789 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1790 (((drm_vblank_count(dev
, pipe
) -
1791 vblwait
->request
.sequence
) <= (1 << 23)) ||
1793 !dev
->irq_enabled
));
1795 if (ret
!= -EINTR
) {
1798 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1799 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1800 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1802 DRM_DEBUG_VBLANK("returning %d to client\n",
1803 vblwait
->reply
.sequence
);
1805 DRM_DEBUG_VBLANK("vblank wait interrupted by signal\n");
1809 drm_vblank_put(dev
, pipe
);
1813 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1815 struct drm_pending_vblank_event
*e
, *t
;
1819 assert_spin_locked(&dev
->event_lock
);
1821 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1823 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1824 if (e
->pipe
!= pipe
)
1826 if ((seq
- e
->event
.sequence
) > (1<<23))
1829 DRM_DEBUG_VBLANK("vblank event on %d, current %d\n",
1830 e
->event
.sequence
, seq
);
1832 list_del(&e
->base
.link
);
1833 drm_vblank_put(dev
, pipe
);
1834 send_vblank_event(dev
, e
, seq
, &now
);
1837 trace_drm_vblank_event(pipe
, seq
);
1841 * drm_handle_vblank - handle a vblank event
1843 * @pipe: index of CRTC where this event occurred
1845 * Drivers should call this routine in their vblank interrupt handlers to
1846 * update the vblank counter and send any signals that may be pending.
1848 * This is the legacy version of drm_crtc_handle_vblank().
1850 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1852 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1853 unsigned long irqflags
;
1855 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1858 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1861 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1863 /* Need timestamp lock to prevent concurrent execution with
1864 * vblank enable/disable, as this would cause inconsistent
1865 * or corrupted timestamps and vblank counts.
1867 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1869 /* Vblank irq handling disabled. Nothing to do. */
1870 if (!vblank
->enabled
) {
1871 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1872 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1876 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1878 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1880 wake_up(&vblank
->queue
);
1881 drm_handle_vblank_events(dev
, pipe
);
1883 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1887 EXPORT_SYMBOL(drm_handle_vblank
);
1890 * drm_crtc_handle_vblank - handle a vblank event
1891 * @crtc: where this event occurred
1893 * Drivers should call this routine in their vblank interrupt handlers to
1894 * update the vblank counter and send any signals that may be pending.
1896 * This is the native KMS version of drm_handle_vblank().
1899 * True if the event was successfully handled, false on failure.
1901 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1903 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1905 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1908 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1910 * @pipe: CRTC for which to read the counter
1912 * Drivers can plug this into the .get_vblank_counter() function if
1913 * there is no useable hardware frame counter available.
1918 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1922 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);