2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, pipe, count) \
47 ((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
61 struct timeval
*tvblank
, unsigned flags
);
63 unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
66 * Default to use monotonic timestamps for wait-for-vblank and page-flip
69 unsigned int drm_timestamp_monotonic
= 1;
71 int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
73 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
74 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
75 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
76 MODULE_PARM_DESC(vblankoffdelay
, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
77 MODULE_PARM_DESC(timestamp_precision_usec
, "Max. error on timestamps [usecs]");
78 MODULE_PARM_DESC(timestamp_monotonic
, "Use monotonic timestamps");
80 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
82 struct timeval
*t_vblank
, u32 last
)
84 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
87 assert_spin_locked(&dev
->vblank_time_lock
);
91 /* All writers hold the spinlock, but readers are serialized by
92 * the latching of vblank->count below.
94 tslot
= vblank
->count
+ vblank_count_inc
;
95 vblanktimestamp(dev
, pipe
, tslot
) = *t_vblank
;
98 * vblank timestamp updates are protected on the write side with
99 * vblank_time_lock, but on the read side done locklessly using a
100 * sequence-lock on the vblank counter. Ensure correct ordering using
101 * memory barrriers. We need the barrier both before and also after the
102 * counter update to synchronize with the next timestamp write.
103 * The read-side barriers for this are in drm_vblank_count_and_time.
106 vblank
->count
+= vblank_count_inc
;
111 * drm_reset_vblank_timestamp - reset the last timestamp to the last vblank
113 * @pipe: index of CRTC for which to reset the timestamp
115 * Reset the stored timestamp for the current vblank count to correspond
116 * to the last vblank occurred.
118 * Only to be called from drm_vblank_on().
120 * Note: caller must hold dev->vbl_lock since this reads & writes
121 * device vblank fields.
123 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
127 struct timeval t_vblank
;
128 int count
= DRM_TIMESTAMP_MAXRETRIES
;
130 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
133 * sample the current counter to avoid random jumps
134 * when drm_vblank_enable() applies the diff
137 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
138 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
139 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
142 * Only reinitialize corresponding vblank timestamp if high-precision query
143 * available and didn't fail. Otherwise reinitialize delayed at next vblank
144 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
147 t_vblank
= (struct timeval
) {0, 0};
150 * +1 to make sure user will never see the same
151 * vblank counter value before and after a modeset
153 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
155 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
159 * drm_update_vblank_count - update the master vblank counter
161 * @pipe: counter to update
163 * Call back into the driver to update the appropriate vblank counter
164 * (specified by @pipe). Deal with wraparound, if it occurred, and
165 * update the last read value so we can deal with wraparound on the next
168 * Only necessary when going from off->on, to account for frames we
169 * didn't get an interrupt for.
171 * Note: caller must hold dev->vbl_lock since this reads & writes
172 * device vblank fields.
174 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
177 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
178 u32 cur_vblank
, diff
;
180 struct timeval t_vblank
;
181 int count
= DRM_TIMESTAMP_MAXRETRIES
;
182 int framedur_ns
= vblank
->framedur_ns
;
185 * Interrupts were disabled prior to this call, so deal with counter
187 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
188 * here if the register is small or we had vblank interrupts off for
191 * We repeat the hardware vblank counter & timestamp query until
192 * we get consistent results. This to prevent races between gpu
193 * updating its hardware counter while we are retrieving the
194 * corresponding vblank timestamp.
197 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
198 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
199 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
201 if (dev
->max_vblank_count
!= 0) {
202 /* trust the hw counter when it's around */
203 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
204 } else if (rc
&& framedur_ns
) {
205 const struct timeval
*t_old
;
208 t_old
= &vblanktimestamp(dev
, pipe
, vblank
->count
);
209 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
212 * Figure out how many vblanks we've missed based
213 * on the difference in the timestamps and the
214 * frame/field duration.
216 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
218 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
219 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
220 " diff_ns = %lld, framedur_ns = %d)\n",
221 pipe
, (long long) diff_ns
, framedur_ns
);
223 /* some kind of default for drivers w/o accurate vbl timestamping */
224 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
228 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
229 * interval? If so then vblank irqs keep running and it will likely
230 * happen that the hardware vblank counter is not trustworthy as it
231 * might reset at some point in that interval and vblank timestamps
232 * are not trustworthy either in that interval. Iow. this can result
233 * in a bogus diff >> 1 which must be avoided as it would cause
234 * random large forward jumps of the software vblank counter.
236 if (diff
> 1 && (vblank
->inmodeset
& 0x2)) {
237 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
238 " due to pre-modeset.\n", pipe
, diff
);
243 * FIMXE: Need to replace this hack with proper seqlocks.
245 * Restrict the bump of the software vblank counter to a safe maximum
246 * value of +1 whenever there is the possibility that concurrent readers
247 * of vblank timestamps could be active at the moment, as the current
248 * implementation of the timestamp caching and updating is not safe
249 * against concurrent readers for calls to store_vblank() with a bump
250 * of anything but +1. A bump != 1 would very likely return corrupted
251 * timestamps to userspace, because the same slot in the cache could
252 * be concurrently written by store_vblank() and read by one of those
253 * readers without the read-retry logic detecting the collision.
255 * Concurrent readers can exist when we are called from the
256 * drm_vblank_off() or drm_vblank_on() functions and other non-vblank-
257 * irq callers. However, all those calls to us are happening with the
258 * vbl_lock locked to prevent drm_vblank_get(), so the vblank refcount
259 * can't increase while we are executing. Therefore a zero refcount at
260 * this point is safe for arbitrary counter bumps if we are called
261 * outside vblank irq, a non-zero count is not 100% safe. Unfortunately
262 * we must also accept a refcount of 1, as whenever we are called from
263 * drm_vblank_get() -> drm_vblank_enable() the refcount will be 1 and
264 * we must let that one pass through in order to not lose vblank counts
265 * during vblank irq off - which would completely defeat the whole
266 * point of this routine.
268 * Whenever we are called from vblank irq, we have to assume concurrent
269 * readers exist or can show up any time during our execution, even if
270 * the refcount is currently zero, as vblank irqs are usually only
271 * enabled due to the presence of readers, and because when we are called
272 * from vblank irq we can't hold the vbl_lock to protect us from sudden
273 * bumps in vblank refcount. Therefore also restrict bumps to +1 when
274 * called from vblank irq.
276 if ((diff
> 1) && (atomic_read(&vblank
->refcount
) > 1 ||
277 (flags
& DRM_CALLED_FROM_VBLIRQ
))) {
278 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u "
279 "refcount %u, vblirq %u\n", pipe
, diff
,
280 atomic_read(&vblank
->refcount
),
281 (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0);
285 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
286 " current=%u, diff=%u, hw=%u hw_last=%u\n",
287 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
290 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
295 * Only reinitialize corresponding vblank timestamp if high-precision query
296 * available and didn't fail, or we were called from the vblank interrupt.
297 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
298 * for now, to mark the vblanktimestamp as invalid.
300 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
301 t_vblank
= (struct timeval
) {0, 0};
303 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
307 * Disable vblank irq's on crtc, make sure that last vblank count
308 * of hardware and corresponding consistent software vblank counter
309 * are preserved, even if there are any spurious vblank irq's after
312 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
314 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
315 unsigned long irqflags
;
317 /* Prevent vblank irq processing while disabling vblank irqs,
318 * so no updates of timestamps or count can happen after we've
319 * disabled. Needed to prevent races in case of delayed irq's.
321 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
324 * Only disable vblank interrupts if they're enabled. This avoids
325 * calling the ->disable_vblank() operation in atomic context with the
326 * hardware potentially runtime suspended.
328 if (vblank
->enabled
) {
329 dev
->driver
->disable_vblank(dev
, pipe
);
330 vblank
->enabled
= false;
334 * Always update the count and timestamp to maintain the
335 * appearance that the counter has been ticking all along until
336 * this time. This makes the count account for the entire time
337 * between drm_vblank_on() and drm_vblank_off().
339 drm_update_vblank_count(dev
, pipe
, 0);
341 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
344 static void vblank_disable_fn(unsigned long arg
)
346 struct drm_vblank_crtc
*vblank
= (void *)arg
;
347 struct drm_device
*dev
= vblank
->dev
;
348 unsigned int pipe
= vblank
->pipe
;
349 unsigned long irqflags
;
351 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
352 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
353 DRM_DEBUG_VBLANK("disabling vblank on crtc %u\n", pipe
);
354 vblank_disable_and_save(dev
, pipe
);
356 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
360 * drm_vblank_cleanup - cleanup vblank support
363 * This function cleans up any resources allocated in drm_vblank_init.
365 void drm_vblank_cleanup(struct drm_device
*dev
)
369 /* Bail if the driver didn't call drm_vblank_init() */
370 if (dev
->num_crtcs
== 0)
373 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
374 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
376 WARN_ON(vblank
->enabled
&&
377 drm_core_check_feature(dev
, DRIVER_MODESET
));
379 del_timer_sync(&vblank
->disable_timer
);
386 EXPORT_SYMBOL(drm_vblank_cleanup
);
389 * drm_vblank_init - initialize vblank support
391 * @num_crtcs: number of CRTCs supported by @dev
393 * This function initializes vblank support for @num_crtcs display pipelines.
396 * Zero on success or a negative error code on failure.
398 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
403 lockinit(&dev
->vbl_lock
, "drmvbl", 0, LK_CANRECURSE
);
404 lockinit(&dev
->vblank_time_lock
, "drmvtl", 0, LK_CANRECURSE
);
406 dev
->num_crtcs
= num_crtcs
;
408 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
412 for (i
= 0; i
< num_crtcs
; i
++) {
413 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
417 init_waitqueue_head(&vblank
->queue
);
418 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
419 (unsigned long)vblank
);
422 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
424 /* Driver specific high-precision vblank timestamping supported? */
425 if (dev
->driver
->get_vblank_timestamp
)
426 DRM_INFO("Driver supports precise vblank timestamp query.\n");
428 DRM_INFO("No driver support for vblank timestamp query.\n");
430 /* Must have precise timestamping for reliable vblank instant disable */
431 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
432 dev
->vblank_disable_immediate
= false;
433 DRM_INFO("Setting vblank_disable_immediate to false because "
434 "get_vblank_timestamp == NULL\n");
443 EXPORT_SYMBOL(drm_vblank_init
);
446 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
448 struct drm_device
*dev
= cookie
;
450 if (dev
->driver
->vgaarb_irq
) {
451 dev
->driver
->vgaarb_irq(dev
, state
);
455 if (!dev
->irq_enabled
)
459 if (dev
->driver
->irq_uninstall
)
460 dev
->driver
->irq_uninstall(dev
);
462 if (dev
->driver
->irq_preinstall
)
463 dev
->driver
->irq_preinstall(dev
);
464 if (dev
->driver
->irq_postinstall
)
465 dev
->driver
->irq_postinstall(dev
);
471 * drm_irq_install - install IRQ handler
473 * @irq: IRQ number to install the handler for
475 * Initializes the IRQ related data. Installs the handler, calling the driver
476 * irq_preinstall() and irq_postinstall() functions before and after the
479 * This is the simplified helper interface provided for drivers with no special
480 * needs. Drivers which need to install interrupt handlers for multiple
481 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
482 * that vblank interrupts are available.
485 * Zero on success or a negative error code on failure.
487 int drm_irq_install(struct drm_device
*dev
, int irq
)
490 unsigned long sh_flags
= 0;
492 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
498 /* Driver must have been initialized */
499 if (!dev
->dev_private
)
502 if (dev
->irq_enabled
)
504 dev
->irq_enabled
= true;
506 DRM_DEBUG("irq=%d\n", irq
);
508 /* Before installing handler */
509 if (dev
->driver
->irq_preinstall
)
510 dev
->driver
->irq_preinstall(dev
);
512 /* Install handler */
513 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
514 sh_flags
= IRQF_SHARED
;
516 ret
= request_irq(irq
, dev
->driver
->irq_handler
,
517 sh_flags
, dev
->driver
->name
, dev
);
520 dev
->irq_enabled
= false;
524 /* After installing handler */
525 if (dev
->driver
->irq_postinstall
)
526 ret
= dev
->driver
->irq_postinstall(dev
);
529 dev
->irq_enabled
= false;
537 EXPORT_SYMBOL(drm_irq_install
);
540 * drm_irq_uninstall - uninstall the IRQ handler
543 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
544 * This should only be called by drivers which used drm_irq_install() to set up
545 * their interrupt handler. Other drivers must only reset
546 * drm_device->irq_enabled to false.
548 * Note that for kernel modesetting drivers it is a bug if this function fails.
549 * The sanity checks are only to catch buggy user modesetting drivers which call
550 * the same function through an ioctl.
553 * Zero on success or a negative error code on failure.
555 int drm_irq_uninstall(struct drm_device
*dev
)
557 unsigned long irqflags
;
561 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
564 irq_enabled
= dev
->irq_enabled
;
565 dev
->irq_enabled
= false;
568 * Wake up any waiters so they don't hang. This is just to paper over
569 * isssues for UMS drivers which aren't in full control of their
570 * vblank/irq handling. KMS drivers must ensure that vblanks are all
571 * disabled when uninstalling the irq handler.
573 if (dev
->num_crtcs
) {
574 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
575 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
576 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
578 if (!vblank
->enabled
)
581 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
583 vblank_disable_and_save(dev
, i
);
584 wake_up(&vblank
->queue
);
586 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
592 DRM_DEBUG("irq=%d\n", dev
->irq
);
594 if (dev
->driver
->irq_uninstall
)
595 dev
->driver
->irq_uninstall(dev
);
597 free_irq(dev
->irq
, dev
);
601 EXPORT_SYMBOL(drm_irq_uninstall
);
606 * \param inode device inode.
607 * \param file_priv DRM file private.
608 * \param cmd command.
609 * \param arg user argument, pointing to a drm_control structure.
610 * \return zero on success or a negative number on failure.
612 * Calls irq_install() or irq_uninstall() according to \p arg.
614 int drm_control(struct drm_device
*dev
, void *data
,
615 struct drm_file
*file_priv
)
617 struct drm_control
*ctl
= data
;
620 /* if we haven't irq we fallback for compatibility reasons -
621 * this used to be a separate function in drm_dma.h
624 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
626 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
628 /* UMS was only ever support on pci devices. */
629 if (WARN_ON(!dev
->pdev
))
633 case DRM_INST_HANDLER
:
634 irq
= dev
->pdev
->irq
;
636 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
639 mutex_lock(&dev
->struct_mutex
);
640 ret
= drm_irq_install(dev
, irq
);
641 mutex_unlock(&dev
->struct_mutex
);
644 case DRM_UNINST_HANDLER
:
645 mutex_lock(&dev
->struct_mutex
);
646 ret
= drm_irq_uninstall(dev
);
647 mutex_unlock(&dev
->struct_mutex
);
656 * drm_calc_timestamping_constants - calculate vblank timestamp constants
657 * @crtc: drm_crtc whose timestamp constants should be updated.
658 * @mode: display mode containing the scanout timings
660 * Calculate and store various constants which are later
661 * needed by vblank and swap-completion timestamping, e.g,
662 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
663 * derived from CRTC's true scanout timing, so they take
664 * things like panel scaling or other adjustments into account.
666 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
667 const struct drm_display_mode
*mode
)
669 struct drm_device
*dev
= crtc
->dev
;
670 unsigned int pipe
= drm_crtc_index(crtc
);
671 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
672 int linedur_ns
= 0, framedur_ns
= 0;
673 int dotclock
= mode
->crtc_clock
;
678 if (WARN_ON(pipe
>= dev
->num_crtcs
))
681 /* Valid dotclock? */
683 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
686 * Convert scanline length in pixels and video
687 * dot clock to line duration and frame duration
690 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
691 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
694 * Fields of interlaced scanout modes are only half a frame duration.
696 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
699 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
702 vblank
->linedur_ns
= linedur_ns
;
703 vblank
->framedur_ns
= framedur_ns
;
705 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
706 crtc
->base
.id
, mode
->crtc_htotal
,
707 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
708 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
709 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
711 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
714 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
716 * @pipe: index of CRTC whose vblank timestamp to retrieve
717 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
718 * On return contains true maximum error of timestamp
719 * @vblank_time: Pointer to struct timeval which should receive the timestamp
720 * @flags: Flags to pass to driver:
722 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
723 * @mode: mode which defines the scanout timings
725 * Implements calculation of exact vblank timestamps from given drm_display_mode
726 * timings and current video scanout position of a CRTC. This can be called from
727 * within get_vblank_timestamp() implementation of a kms driver to implement the
728 * actual timestamping.
730 * Should return timestamps conforming to the OML_sync_control OpenML
731 * extension specification. The timestamp corresponds to the end of
732 * the vblank interval, aka start of scanout of topmost-leftmost display
733 * pixel in the following video frame.
735 * Requires support for optional dev->driver->get_scanout_position()
736 * in kms driver, plus a bit of setup code to provide a drm_display_mode
737 * that corresponds to the true scanout timing.
739 * The current implementation only handles standard video modes. It
740 * returns as no operation if a doublescan or interlaced video mode is
741 * active. Higher level code is expected to handle this.
744 * Negative value on error, failure or if not supported in current
747 * -EINVAL - Invalid CRTC.
748 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
749 * -ENOTSUPP - Function not supported in current display mode.
750 * -EIO - Failed, e.g., due to failed scanout position query.
752 * Returns or'ed positive status flags on success:
754 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
755 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
758 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
761 struct timeval
*vblank_time
,
763 const struct drm_display_mode
*mode
)
765 struct timeval tv_etime
;
766 ktime_t stime
, etime
;
767 unsigned int vbl_status
;
768 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
770 int delta_ns
, duration_ns
;
772 if (pipe
>= dev
->num_crtcs
) {
773 DRM_ERROR("Invalid crtc %u\n", pipe
);
777 /* Scanout position query not supported? Should not happen. */
778 if (!dev
->driver
->get_scanout_position
) {
779 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
783 /* If mode timing undefined, just return as no-op:
784 * Happens during initial modesetting of a crtc.
786 if (mode
->crtc_clock
== 0) {
787 DRM_DEBUG_VBLANK("crtc %u: Noop due to uninitialized mode.\n", pipe
);
791 /* Get current scanout position with system timestamp.
792 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
793 * if single query takes longer than max_error nanoseconds.
795 * This guarantees a tight bound on maximum error if
796 * code gets preempted or delayed for some reason.
798 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
800 * Get vertical and horizontal scanout position vpos, hpos,
801 * and bounding timestamps stime, etime, pre/post query.
803 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
808 /* Return as no-op if scanout query unsupported or failed. */
809 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
810 DRM_DEBUG_VBLANK("crtc %u : scanoutpos query failed [0x%x].\n",
815 /* Compute uncertainty in timestamp of scanout position query. */
816 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
818 /* Accept result with < max_error nsecs timing uncertainty. */
819 if (duration_ns
<= *max_error
)
823 /* Noisy system timing? */
824 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
825 DRM_DEBUG_VBLANK("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
826 pipe
, duration_ns
/1000, *max_error
/1000, i
);
829 /* Return upper bound of timestamp precision error. */
830 *max_error
= duration_ns
;
832 /* Check if in vblank area:
833 * vpos is >=0 in video scanout area, but negative
834 * within vblank area, counting down the number of lines until
837 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
838 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
840 /* Convert scanout position into elapsed time at raw_time query
841 * since start of scanout at first display scanline. delta_ns
842 * can be negative if start of scanout hasn't happened yet.
844 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
847 if (!drm_timestamp_monotonic
)
848 etime
= ktime_mono_to_real(etime
);
850 /* save this only for debugging purposes */
851 tv_etime
= ktime_to_timeval(etime
);
852 /* Subtract time delta from raw timestamp to get final
853 * vblank_time timestamp for end of vblank.
855 etime
= ktime_sub_ns(etime
, delta_ns
);
856 *vblank_time
= ktime_to_timeval(etime
);
858 DRM_DEBUG_VBLANK("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
859 pipe
, vbl_status
, hpos
, vpos
,
860 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
861 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
862 duration_ns
/1000, i
);
866 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
868 static struct timeval
get_drm_timestamp(void)
872 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
873 return ktime_to_timeval(now
);
877 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
880 * @pipe: index of CRTC whose vblank timestamp to retrieve
881 * @tvblank: Pointer to target struct timeval which should receive the timestamp
882 * @flags: Flags to pass to driver:
884 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
886 * Fetches the system timestamp corresponding to the time of the most recent
887 * vblank interval on specified CRTC. May call into kms-driver to
888 * compute the timestamp with a high-precision GPU specific method.
890 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
891 * call, i.e., it isn't very precisely locked to the true vblank.
894 * True if timestamp is considered to be very precise, false otherwise.
897 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
898 struct timeval
*tvblank
, unsigned flags
)
902 /* Define requested maximum error on timestamps (nanoseconds). */
903 int max_error
= (int) drm_timestamp_precision
* 1000;
905 /* Query driver if possible and precision timestamping enabled. */
906 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
907 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
913 /* GPU high precision timestamp query unsupported or failed.
914 * Return current monotonic/gettimeofday timestamp as best estimate.
916 *tvblank
= get_drm_timestamp();
922 * drm_vblank_count - retrieve "cooked" vblank counter value
924 * @pipe: index of CRTC for which to retrieve the counter
926 * Fetches the "cooked" vblank count value that represents the number of
927 * vblank events since the system was booted, including lost events due to
928 * modesetting activity.
930 * This is the legacy version of drm_crtc_vblank_count().
933 * The software vblank counter.
935 u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
937 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
939 if (WARN_ON(pipe
>= dev
->num_crtcs
))
942 return vblank
->count
;
944 EXPORT_SYMBOL(drm_vblank_count
);
947 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
948 * @crtc: which counter to retrieve
950 * Fetches the "cooked" vblank count value that represents the number of
951 * vblank events since the system was booted, including lost events due to
952 * modesetting activity.
954 * This is the native KMS version of drm_vblank_count().
957 * The software vblank counter.
959 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
961 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
963 EXPORT_SYMBOL(drm_crtc_vblank_count
);
966 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
967 * system timestamp corresponding to that vblank counter value.
969 * @pipe: index of CRTC whose counter to retrieve
970 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
972 * Fetches the "cooked" vblank count value that represents the number of
973 * vblank events since the system was booted, including lost events due to
974 * modesetting activity. Returns corresponding system timestamp of the time
975 * of the vblank interval that corresponds to the current vblank counter value.
977 * This is the legacy version of drm_crtc_vblank_count_and_time().
979 u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
980 struct timeval
*vblanktime
)
982 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
983 int count
= DRM_TIMESTAMP_MAXRETRIES
;
986 vblanktime
->tv_sec
= 0; /* silence gcc warning */
987 vblanktime
->tv_usec
= 0; /* silence gcc warning */
988 if (WARN_ON(pipe
>= dev
->num_crtcs
))
992 * Vblank timestamps are read lockless. To ensure consistency the vblank
993 * counter is rechecked and ordering is ensured using memory barriers.
994 * This works like a seqlock. The write-side barriers are in store_vblank.
997 cur_vblank
= vblank
->count
;
999 *vblanktime
= vblanktimestamp(dev
, pipe
, cur_vblank
);
1001 } while (cur_vblank
!= vblank
->count
&& --count
> 0);
1005 EXPORT_SYMBOL(drm_vblank_count_and_time
);
1008 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
1009 * and the system timestamp corresponding to that vblank counter value
1010 * @crtc: which counter to retrieve
1011 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
1013 * Fetches the "cooked" vblank count value that represents the number of
1014 * vblank events since the system was booted, including lost events due to
1015 * modesetting activity. Returns corresponding system timestamp of the time
1016 * of the vblank interval that corresponds to the current vblank counter value.
1018 * This is the native KMS version of drm_vblank_count_and_time().
1020 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
1021 struct timeval
*vblanktime
)
1023 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
1026 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
1028 static void send_vblank_event(struct drm_device
*dev
,
1029 struct drm_pending_vblank_event
*e
,
1030 unsigned long seq
, struct timeval
*now
)
1032 e
->event
.sequence
= seq
;
1033 e
->event
.tv_sec
= now
->tv_sec
;
1034 e
->event
.tv_usec
= now
->tv_usec
;
1036 drm_send_event_locked(dev
, &e
->base
);
1038 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1043 * drm_arm_vblank_event - arm vblank event after pageflip
1046 * @e: the event to prepare to send
1048 * A lot of drivers need to generate vblank events for the very next vblank
1049 * interrupt. For example when the page flip interrupt happens when the page
1050 * flip gets armed, but not when it actually executes within the next vblank
1051 * period. This helper function implements exactly the required vblank arming
1054 * Caller must hold event lock. Caller must also hold a vblank reference for
1055 * the event @e, which will be dropped when the next vblank arrives.
1057 * This is the legacy version of drm_crtc_arm_vblank_event().
1059 void drm_arm_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1060 struct drm_pending_vblank_event
*e
)
1062 assert_spin_locked(&dev
->event_lock
);
1065 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1066 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1068 EXPORT_SYMBOL(drm_arm_vblank_event
);
1071 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
1072 * @crtc: the source CRTC of the vblank event
1073 * @e: the event to send
1075 * A lot of drivers need to generate vblank events for the very next vblank
1076 * interrupt. For example when the page flip interrupt happens when the page
1077 * flip gets armed, but not when it actually executes within the next vblank
1078 * period. This helper function implements exactly the required vblank arming
1081 * Caller must hold event lock. Caller must also hold a vblank reference for
1082 * the event @e, which will be dropped when the next vblank arrives.
1084 * This is the native KMS version of drm_arm_vblank_event().
1086 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1087 struct drm_pending_vblank_event
*e
)
1089 drm_arm_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1091 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1094 * drm_send_vblank_event - helper to send vblank event after pageflip
1097 * @e: the event to send
1099 * Updates sequence # and timestamp on event, and sends it to userspace.
1100 * Caller must hold event lock.
1102 * This is the legacy version of drm_crtc_send_vblank_event().
1104 void drm_send_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1105 struct drm_pending_vblank_event
*e
)
1110 if (dev
->num_crtcs
> 0) {
1111 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1115 now
= get_drm_timestamp();
1118 send_vblank_event(dev
, e
, seq
, &now
);
1120 EXPORT_SYMBOL(drm_send_vblank_event
);
1123 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1124 * @crtc: the source CRTC of the vblank event
1125 * @e: the event to send
1127 * Updates sequence # and timestamp on event, and sends it to userspace.
1128 * Caller must hold event lock.
1130 * This is the native KMS version of drm_send_vblank_event().
1132 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1133 struct drm_pending_vblank_event
*e
)
1135 drm_send_vblank_event(crtc
->dev
, drm_crtc_index(crtc
), e
);
1137 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1140 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1145 * Zero on success or a negative error code on failure.
1147 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1149 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1152 assert_spin_locked(&dev
->vbl_lock
);
1154 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1156 if (!vblank
->enabled
) {
1158 * Enable vblank irqs under vblank_time_lock protection.
1159 * All vblank count & timestamp updates are held off
1160 * until we are done reinitializing master counter and
1161 * timestamps. Filtercode in drm_handle_vblank() will
1162 * prevent double-accounting of same vblank interval.
1164 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1165 DRM_DEBUG_VBLANK("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1167 atomic_dec(&vblank
->refcount
);
1169 vblank
->enabled
= true;
1170 drm_update_vblank_count(dev
, pipe
, 0);
1174 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1180 * drm_vblank_get - get a reference count on vblank events
1182 * @pipe: index of CRTC to own
1184 * Acquire a reference count on vblank events to avoid having them disabled
1187 * This is the legacy version of drm_crtc_vblank_get().
1190 * Zero on success or a negative error code on failure.
1192 int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1194 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1195 unsigned long irqflags
;
1198 if (!dev
->num_crtcs
)
1201 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1204 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1205 /* Going from 0->1 means we have to enable interrupts again */
1206 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1207 ret
= drm_vblank_enable(dev
, pipe
);
1209 if (!vblank
->enabled
) {
1210 atomic_dec(&vblank
->refcount
);
1214 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1218 EXPORT_SYMBOL(drm_vblank_get
);
1221 * drm_crtc_vblank_get - get a reference count on vblank events
1222 * @crtc: which CRTC to own
1224 * Acquire a reference count on vblank events to avoid having them disabled
1227 * This is the native kms version of drm_vblank_get().
1230 * Zero on success or a negative error code on failure.
1232 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1234 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1236 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1239 * drm_vblank_put - release ownership of vblank events
1241 * @pipe: index of CRTC to release
1243 * Release ownership of a given vblank counter, turning off interrupts
1244 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1246 * This is the legacy version of drm_crtc_vblank_put().
1248 void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1250 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1252 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1255 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1258 /* Last user schedules interrupt disable */
1259 if (atomic_dec_and_test(&vblank
->refcount
)) {
1260 if (drm_vblank_offdelay
== 0)
1262 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1263 vblank_disable_fn((unsigned long)vblank
);
1265 mod_timer(&vblank
->disable_timer
,
1266 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1269 EXPORT_SYMBOL(drm_vblank_put
);
1272 * drm_crtc_vblank_put - give up ownership of vblank events
1273 * @crtc: which counter to give up
1275 * Release ownership of a given vblank counter, turning off interrupts
1276 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1278 * This is the native kms version of drm_vblank_put().
1280 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1282 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1284 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1287 * drm_wait_one_vblank - wait for one vblank
1291 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1292 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1293 * due to lack of driver support or because the crtc is off.
1295 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1297 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1301 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1304 ret
= drm_vblank_get(dev
, pipe
);
1305 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1308 last
= drm_vblank_count(dev
, pipe
);
1310 ret
= wait_event_timeout(vblank
->queue
,
1311 last
!= drm_vblank_count(dev
, pipe
),
1312 msecs_to_jiffies(100));
1314 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1316 drm_vblank_put(dev
, pipe
);
1318 EXPORT_SYMBOL(drm_wait_one_vblank
);
1321 * drm_crtc_wait_one_vblank - wait for one vblank
1324 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1325 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1326 * due to lack of driver support or because the crtc is off.
1328 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1330 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1332 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1335 * drm_vblank_off - disable vblank events on a CRTC
1339 * Drivers can use this function to shut down the vblank interrupt handling when
1340 * disabling a crtc. This function ensures that the latest vblank frame count is
1341 * stored so that drm_vblank_on() can restore it again.
1343 * Drivers must use this function when the hardware vblank counter can get
1344 * reset, e.g. when suspending.
1346 * This is the legacy version of drm_crtc_vblank_off().
1348 void drm_vblank_off(struct drm_device
*dev
, unsigned int pipe
)
1350 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1351 struct drm_pending_vblank_event
*e
, *t
;
1353 unsigned long irqflags
;
1356 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1359 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1361 lockmgr(&dev
->vbl_lock
, LK_EXCLUSIVE
);
1362 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1363 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1365 /* Avoid redundant vblank disables without previous drm_vblank_on(). */
1366 if (drm_core_check_feature(dev
, DRIVER_ATOMIC
) || !vblank
->inmodeset
)
1367 vblank_disable_and_save(dev
, pipe
);
1369 wake_up(&vblank
->queue
);
1372 * Prevent subsequent drm_vblank_get() from re-enabling
1373 * the vblank interrupt by bumping the refcount.
1375 if (!vblank
->inmodeset
) {
1376 atomic_inc(&vblank
->refcount
);
1377 vblank
->inmodeset
= 1;
1379 lockmgr(&dev
->vbl_lock
, LK_RELEASE
);
1381 /* Send any queued vblank events, lest the natives grow disquiet */
1382 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1384 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1385 if (e
->pipe
!= pipe
)
1387 DRM_DEBUG_VBLANK("Sending premature vblank event on disable: \
1388 wanted %d, current %d\n",
1389 e
->event
.sequence
, seq
);
1390 list_del(&e
->base
.link
);
1391 drm_vblank_put(dev
, pipe
);
1392 send_vblank_event(dev
, e
, seq
, &now
);
1394 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1396 EXPORT_SYMBOL(drm_vblank_off
);
1399 * drm_crtc_vblank_off - disable vblank events on a CRTC
1400 * @crtc: CRTC in question
1402 * Drivers can use this function to shut down the vblank interrupt handling when
1403 * disabling a crtc. This function ensures that the latest vblank frame count is
1404 * stored so that drm_vblank_on can restore it again.
1406 * Drivers must use this function when the hardware vblank counter can get
1407 * reset, e.g. when suspending.
1409 * This is the native kms version of drm_vblank_off().
1411 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1413 drm_vblank_off(crtc
->dev
, drm_crtc_index(crtc
));
1415 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1418 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1419 * @crtc: CRTC in question
1421 * Drivers can use this function to reset the vblank state to off at load time.
1422 * Drivers should use this together with the drm_crtc_vblank_off() and
1423 * drm_crtc_vblank_on() functions. The difference compared to
1424 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1425 * and hence doesn't need to call any driver hooks.
1427 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1429 struct drm_device
*dev
= crtc
->dev
;
1430 unsigned long irqflags
;
1431 unsigned int pipe
= drm_crtc_index(crtc
);
1432 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1434 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1436 * Prevent subsequent drm_vblank_get() from enabling the vblank
1437 * interrupt by bumping the refcount.
1439 if (!vblank
->inmodeset
) {
1440 atomic_inc(&vblank
->refcount
);
1441 vblank
->inmodeset
= 1;
1443 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1445 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1447 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1450 * drm_vblank_on - enable vblank events on a CRTC
1454 * This functions restores the vblank interrupt state captured with
1455 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1456 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1457 * in driver load code to reflect the current hardware state of the crtc.
1459 * This is the legacy version of drm_crtc_vblank_on().
1461 void drm_vblank_on(struct drm_device
*dev
, unsigned int pipe
)
1463 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1464 unsigned long irqflags
;
1466 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1469 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1470 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1471 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1473 /* Drop our private "prevent drm_vblank_get" refcount */
1474 if (vblank
->inmodeset
) {
1475 atomic_dec(&vblank
->refcount
);
1476 vblank
->inmodeset
= 0;
1479 drm_reset_vblank_timestamp(dev
, pipe
);
1482 * re-enable interrupts if there are users left, or the
1483 * user wishes vblank interrupts to be enabled all the time.
1485 if (atomic_read(&vblank
->refcount
) != 0 || drm_vblank_offdelay
== 0)
1486 WARN_ON(drm_vblank_enable(dev
, pipe
));
1487 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1489 EXPORT_SYMBOL(drm_vblank_on
);
1492 * drm_crtc_vblank_on - enable vblank events on a CRTC
1493 * @crtc: CRTC in question
1495 * This functions restores the vblank interrupt state captured with
1496 * drm_vblank_off() again. Note that calls to drm_vblank_on() and
1497 * drm_vblank_off() can be unbalanced and so can also be unconditionally called
1498 * in driver load code to reflect the current hardware state of the crtc.
1500 * This is the native kms version of drm_vblank_on().
1502 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1504 drm_vblank_on(crtc
->dev
, drm_crtc_index(crtc
));
1506 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1509 * drm_vblank_pre_modeset - account for vblanks across mode sets
1513 * Account for vblank events across mode setting events, which will likely
1514 * reset the hardware frame counter.
1516 * This is done by grabbing a temporary vblank reference to ensure that the
1517 * vblank interrupt keeps running across the modeset sequence. With this the
1518 * software-side vblank frame counting will ensure that there are no jumps or
1521 * Unfortunately this approach is racy and also doesn't work when the vblank
1522 * interrupt stops running, e.g. across system suspend resume. It is therefore
1523 * highly recommended that drivers use the newer drm_vblank_off() and
1524 * drm_vblank_on() instead. drm_vblank_pre_modeset() only works correctly when
1525 * using "cooked" software vblank frame counters and not relying on any hardware
1528 * Drivers must call drm_vblank_post_modeset() when re-enabling the same crtc
1531 void drm_vblank_pre_modeset(struct drm_device
*dev
, unsigned int pipe
)
1533 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1535 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1536 if (!dev
->num_crtcs
)
1539 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1543 * To avoid all the problems that might happen if interrupts
1544 * were enabled/disabled around or between these calls, we just
1545 * have the kernel take a reference on the CRTC (just once though
1546 * to avoid corrupting the count if multiple, mismatch calls occur),
1547 * so that interrupts remain enabled in the interim.
1549 if (!vblank
->inmodeset
) {
1550 vblank
->inmodeset
= 0x1;
1551 if (drm_vblank_get(dev
, pipe
) == 0)
1552 vblank
->inmodeset
|= 0x2;
1555 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1558 * drm_vblank_post_modeset - undo drm_vblank_pre_modeset changes
1562 * This function again drops the temporary vblank reference acquired in
1563 * drm_vblank_pre_modeset.
1565 void drm_vblank_post_modeset(struct drm_device
*dev
, unsigned int pipe
)
1567 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1568 unsigned long irqflags
;
1570 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1571 if (!dev
->num_crtcs
)
1574 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1577 if (vblank
->inmodeset
) {
1578 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1579 drm_reset_vblank_timestamp(dev
, pipe
);
1580 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1582 if (vblank
->inmodeset
& 0x2)
1583 drm_vblank_put(dev
, pipe
);
1585 vblank
->inmodeset
= 0;
1588 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1591 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1592 * @DRM_IOCTL_ARGS: standard ioctl arguments
1594 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1595 * ioctls around modesetting so that any lost vblank events are accounted for.
1597 * Generally the counter will reset across mode sets. If interrupts are
1598 * enabled around this call, we don't have to do anything since the counter
1599 * will have already been incremented.
1601 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1602 struct drm_file
*file_priv
)
1604 struct drm_modeset_ctl
*modeset
= data
;
1607 /* If drm_vblank_init() hasn't been called yet, just no-op */
1608 if (!dev
->num_crtcs
)
1611 /* KMS drivers handle this internally */
1612 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
1615 pipe
= modeset
->crtc
;
1616 if (pipe
>= dev
->num_crtcs
)
1619 switch (modeset
->cmd
) {
1620 case _DRM_PRE_MODESET
:
1621 drm_vblank_pre_modeset(dev
, pipe
);
1623 case _DRM_POST_MODESET
:
1624 drm_vblank_post_modeset(dev
, pipe
);
1633 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1634 union drm_wait_vblank
*vblwait
,
1635 struct drm_file
*file_priv
)
1637 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1638 struct drm_pending_vblank_event
*e
;
1640 unsigned long flags
;
1644 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1651 e
->base
.pid
= curproc
->p_pid
;
1652 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1653 e
->event
.base
.length
= sizeof(e
->event
);
1654 e
->event
.user_data
= vblwait
->request
.signal
;
1656 spin_lock_irqsave(&dev
->event_lock
, flags
);
1659 * drm_vblank_off() might have been called after we called
1660 * drm_vblank_get(). drm_vblank_off() holds event_lock
1661 * around the vblank disable, so no need for further locking.
1662 * The reference from drm_vblank_get() protects against
1663 * vblank disable from another source.
1665 if (!vblank
->enabled
) {
1670 ret
= drm_event_reserve_init_locked(dev
, file_priv
, &e
->base
,
1676 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1678 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1679 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1680 vblwait
->request
.sequence
= seq
+ 1;
1681 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1684 DRM_DEBUG_VBLANK("event on vblank count %d, current %d, crtc %u\n",
1685 vblwait
->request
.sequence
, seq
, pipe
);
1687 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1688 vblwait
->request
.sequence
);
1690 e
->event
.sequence
= vblwait
->request
.sequence
;
1691 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1692 drm_vblank_put(dev
, pipe
);
1693 send_vblank_event(dev
, e
, seq
, &now
);
1694 vblwait
->reply
.sequence
= seq
;
1696 /* drm_handle_vblank_events will call drm_vblank_put */
1697 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1698 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1701 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1706 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1709 drm_vblank_put(dev
, pipe
);
1716 * \param inode device inode.
1717 * \param file_priv DRM file private.
1718 * \param cmd command.
1719 * \param data user argument, pointing to a drm_wait_vblank structure.
1720 * \return zero on success or a negative number on failure.
1722 * This function enables the vblank interrupt on the pipe requested, then
1723 * sleeps waiting for the requested sequence number to occur, and drops
1724 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1725 * after a timeout with no further vblank waits scheduled).
1727 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1728 struct drm_file
*file_priv
)
1730 struct drm_vblank_crtc
*vblank
;
1731 union drm_wait_vblank
*vblwait
= data
;
1733 unsigned int flags
, seq
, pipe
, high_pipe
;
1735 if (!dev
->irq_enabled
)
1738 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1741 if (vblwait
->request
.type
&
1742 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1743 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1744 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1745 vblwait
->request
.type
,
1746 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1747 _DRM_VBLANK_HIGH_CRTC_MASK
));
1751 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1752 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1754 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1756 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1757 if (pipe
>= dev
->num_crtcs
)
1760 vblank
= &dev
->vblank
[pipe
];
1762 ret
= drm_vblank_get(dev
, pipe
);
1764 DRM_DEBUG_VBLANK("failed to acquire vblank counter, %d\n", ret
);
1767 seq
= drm_vblank_count(dev
, pipe
);
1769 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1770 case _DRM_VBLANK_RELATIVE
:
1771 vblwait
->request
.sequence
+= seq
;
1772 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1773 case _DRM_VBLANK_ABSOLUTE
:
1780 if (flags
& _DRM_VBLANK_EVENT
) {
1781 /* must hold on to the vblank ref until the event fires
1782 * drm_vblank_put will be called asynchronously
1784 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1787 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1788 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1789 vblwait
->request
.sequence
= seq
+ 1;
1792 DRM_DEBUG_VBLANK("waiting on vblank count %d, crtc %u\n",
1793 vblwait
->request
.sequence
, pipe
);
1794 vblank
->last_wait
= vblwait
->request
.sequence
;
1795 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1796 (((drm_vblank_count(dev
, pipe
) -
1797 vblwait
->request
.sequence
) <= (1 << 23)) ||
1799 !dev
->irq_enabled
));
1801 if (ret
!= -EINTR
) {
1804 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1805 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1806 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1808 DRM_DEBUG_VBLANK("returning %d to client\n",
1809 vblwait
->reply
.sequence
);
1811 DRM_DEBUG_VBLANK("vblank wait interrupted by signal\n");
1815 drm_vblank_put(dev
, pipe
);
1819 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1821 struct drm_pending_vblank_event
*e
, *t
;
1825 assert_spin_locked(&dev
->event_lock
);
1827 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1829 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1830 if (e
->pipe
!= pipe
)
1832 if ((seq
- e
->event
.sequence
) > (1<<23))
1835 DRM_DEBUG_VBLANK("vblank event on %d, current %d\n",
1836 e
->event
.sequence
, seq
);
1838 list_del(&e
->base
.link
);
1839 drm_vblank_put(dev
, pipe
);
1840 send_vblank_event(dev
, e
, seq
, &now
);
1843 trace_drm_vblank_event(pipe
, seq
);
1847 * drm_handle_vblank - handle a vblank event
1849 * @pipe: index of CRTC where this event occurred
1851 * Drivers should call this routine in their vblank interrupt handlers to
1852 * update the vblank counter and send any signals that may be pending.
1854 * This is the legacy version of drm_crtc_handle_vblank().
1856 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1858 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1859 unsigned long irqflags
;
1861 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1864 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1867 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1869 /* Need timestamp lock to prevent concurrent execution with
1870 * vblank enable/disable, as this would cause inconsistent
1871 * or corrupted timestamps and vblank counts.
1873 lockmgr(&dev
->vblank_time_lock
, LK_EXCLUSIVE
);
1875 /* Vblank irq handling disabled. Nothing to do. */
1876 if (!vblank
->enabled
) {
1877 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1878 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1882 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1884 lockmgr(&dev
->vblank_time_lock
, LK_RELEASE
);
1886 wake_up(&vblank
->queue
);
1887 drm_handle_vblank_events(dev
, pipe
);
1889 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1893 EXPORT_SYMBOL(drm_handle_vblank
);
1896 * drm_crtc_handle_vblank - handle a vblank event
1897 * @crtc: where this event occurred
1899 * Drivers should call this routine in their vblank interrupt handlers to
1900 * update the vblank counter and send any signals that may be pending.
1902 * This is the native KMS version of drm_handle_vblank().
1905 * True if the event was successfully handled, false on failure.
1907 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1909 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1911 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1914 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1916 * @pipe: CRTC for which to read the counter
1918 * Drivers can plug this into the .get_vblank_counter() function if
1919 * there is no useable hardware frame counter available.
1924 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1928 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);