2 * drm_irq.c IRQ and vblank support
4 * \author Rickard E. (Rik) Faith <faith@valinux.com>
5 * \author Gareth Hughes <gareth@valinux.com>
9 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
11 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
12 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
13 * All Rights Reserved.
15 * Permission is hereby granted, free of charge, to any person obtaining a
16 * copy of this software and associated documentation files (the "Software"),
17 * to deal in the Software without restriction, including without limitation
18 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
19 * and/or sell copies of the Software, and to permit persons to whom the
20 * Software is furnished to do so, subject to the following conditions:
22 * The above copyright notice and this permission notice (including the next
23 * paragraph) shall be included in all copies or substantial portions of the
26 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
29 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
30 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
31 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
32 * OTHER DEALINGS IN THE SOFTWARE.
36 #include "drm_trace.h"
37 #include "drm_internal.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Retry timestamp calculation up to 3 times to satisfy
46 * drm_timestamp_precision before giving up.
48 #define DRM_TIMESTAMP_MAXRETRIES 3
50 /* Threshold in nanoseconds for detection of redundant
51 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
53 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
56 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
57 struct timeval
*tvblank
, unsigned flags
);
59 static unsigned int drm_timestamp_precision
= 20; /* Default to 20 usecs. */
62 * Default to use monotonic timestamps for wait-for-vblank and page-flip
65 unsigned int drm_timestamp_monotonic
= 1;
67 static int drm_vblank_offdelay
= 5000; /* Default to 5000 msecs. */
69 module_param_named(vblankoffdelay
, drm_vblank_offdelay
, int, 0600);
70 module_param_named(timestamp_precision_usec
, drm_timestamp_precision
, int, 0600);
71 module_param_named(timestamp_monotonic
, drm_timestamp_monotonic
, int, 0600);
72 MODULE_PARM_DESC(vblankoffdelay
, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)");
73 MODULE_PARM_DESC(timestamp_precision_usec
, "Max. error on timestamps [usecs]");
74 MODULE_PARM_DESC(timestamp_monotonic
, "Use monotonic timestamps");
76 static void store_vblank(struct drm_device
*dev
, unsigned int pipe
,
78 struct timeval
*t_vblank
, u32 last
)
80 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
82 assert_spin_locked(&dev
->vblank_time_lock
);
86 write_seqlock(&vblank
->seqlock
);
87 vblank
->time
= *t_vblank
;
88 vblank
->count
+= vblank_count_inc
;
89 write_sequnlock(&vblank
->seqlock
);
93 * Reset the stored timestamp for the current vblank count to correspond
94 * to the last vblank occurred.
96 * Only to be called from drm_crtc_vblank_on().
98 * Note: caller must hold dev->vbl_lock since this reads & writes
99 * device vblank fields.
101 static void drm_reset_vblank_timestamp(struct drm_device
*dev
, unsigned int pipe
)
105 struct timeval t_vblank
;
106 int count
= DRM_TIMESTAMP_MAXRETRIES
;
108 spin_lock(&dev
->vblank_time_lock
);
111 * sample the current counter to avoid random jumps
112 * when drm_vblank_enable() applies the diff
115 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
116 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, 0);
117 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
120 * Only reinitialize corresponding vblank timestamp if high-precision query
121 * available and didn't fail. Otherwise reinitialize delayed at next vblank
122 * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid.
125 t_vblank
= (struct timeval
) {0, 0};
128 * +1 to make sure user will never see the same
129 * vblank counter value before and after a modeset
131 store_vblank(dev
, pipe
, 1, &t_vblank
, cur_vblank
);
133 spin_unlock(&dev
->vblank_time_lock
);
137 * Call back into the driver to update the appropriate vblank counter
138 * (specified by @pipe). Deal with wraparound, if it occurred, and
139 * update the last read value so we can deal with wraparound on the next
142 * Only necessary when going from off->on, to account for frames we
143 * didn't get an interrupt for.
145 * Note: caller must hold dev->vbl_lock since this reads & writes
146 * device vblank fields.
148 static void drm_update_vblank_count(struct drm_device
*dev
, unsigned int pipe
,
151 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
152 u32 cur_vblank
, diff
;
154 struct timeval t_vblank
;
155 int count
= DRM_TIMESTAMP_MAXRETRIES
;
156 int framedur_ns
= vblank
->framedur_ns
;
159 * Interrupts were disabled prior to this call, so deal with counter
161 * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events
162 * here if the register is small or we had vblank interrupts off for
165 * We repeat the hardware vblank counter & timestamp query until
166 * we get consistent results. This to prevent races between gpu
167 * updating its hardware counter while we are retrieving the
168 * corresponding vblank timestamp.
171 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, pipe
);
172 rc
= drm_get_last_vbltimestamp(dev
, pipe
, &t_vblank
, flags
);
173 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, pipe
) && --count
> 0);
175 if (dev
->max_vblank_count
!= 0) {
176 /* trust the hw counter when it's around */
177 diff
= (cur_vblank
- vblank
->last
) & dev
->max_vblank_count
;
178 } else if (rc
&& framedur_ns
) {
179 const struct timeval
*t_old
;
182 t_old
= &vblank
->time
;
183 diff_ns
= timeval_to_ns(&t_vblank
) - timeval_to_ns(t_old
);
186 * Figure out how many vblanks we've missed based
187 * on the difference in the timestamps and the
188 * frame/field duration.
190 diff
= DIV_ROUND_CLOSEST_ULL(diff_ns
, framedur_ns
);
192 if (diff
== 0 && flags
& DRM_CALLED_FROM_VBLIRQ
)
193 DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored."
194 " diff_ns = %lld, framedur_ns = %d)\n",
195 pipe
, (long long) diff_ns
, framedur_ns
);
197 /* some kind of default for drivers w/o accurate vbl timestamping */
198 diff
= (flags
& DRM_CALLED_FROM_VBLIRQ
) != 0;
202 * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset
203 * interval? If so then vblank irqs keep running and it will likely
204 * happen that the hardware vblank counter is not trustworthy as it
205 * might reset at some point in that interval and vblank timestamps
206 * are not trustworthy either in that interval. Iow. this can result
207 * in a bogus diff >> 1 which must be avoided as it would cause
208 * random large forward jumps of the software vblank counter.
210 if (diff
> 1 && (vblank
->inmodeset
& 0x2)) {
211 DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u"
212 " due to pre-modeset.\n", pipe
, diff
);
216 DRM_DEBUG_VBL("updating vblank count on crtc %u:"
217 " current=%u, diff=%u, hw=%u hw_last=%u\n",
218 pipe
, vblank
->count
, diff
, cur_vblank
, vblank
->last
);
221 WARN_ON_ONCE(cur_vblank
!= vblank
->last
);
226 * Only reinitialize corresponding vblank timestamp if high-precision query
227 * available and didn't fail, or we were called from the vblank interrupt.
228 * Otherwise reinitialize delayed at next vblank interrupt and assign 0
229 * for now, to mark the vblanktimestamp as invalid.
231 if (!rc
&& (flags
& DRM_CALLED_FROM_VBLIRQ
) == 0)
232 t_vblank
= (struct timeval
) {0, 0};
234 store_vblank(dev
, pipe
, diff
, &t_vblank
, cur_vblank
);
237 static u32
drm_vblank_count(struct drm_device
*dev
, unsigned int pipe
)
239 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
241 if (WARN_ON(pipe
>= dev
->num_crtcs
))
244 return vblank
->count
;
248 * drm_accurate_vblank_count - retrieve the master vblank counter
249 * @crtc: which counter to retrieve
251 * This function is similar to @drm_crtc_vblank_count but this
252 * function interpolates to handle a race with vblank irq's.
254 * This is mostly useful for hardware that can obtain the scanout
255 * position, but doesn't have a frame counter.
257 u32
drm_accurate_vblank_count(struct drm_crtc
*crtc
)
259 struct drm_device
*dev
= crtc
->dev
;
260 unsigned int pipe
= drm_crtc_index(crtc
);
264 WARN(!dev
->driver
->get_vblank_timestamp
,
265 "This function requires support for accurate vblank timestamps.");
267 spin_lock_irqsave(&dev
->vblank_time_lock
, flags
);
269 drm_update_vblank_count(dev
, pipe
, 0);
270 vblank
= drm_vblank_count(dev
, pipe
);
272 spin_unlock_irqrestore(&dev
->vblank_time_lock
, flags
);
276 EXPORT_SYMBOL(drm_accurate_vblank_count
);
279 * Disable vblank irq's on crtc, make sure that last vblank count
280 * of hardware and corresponding consistent software vblank counter
281 * are preserved, even if there are any spurious vblank irq's after
284 static void vblank_disable_and_save(struct drm_device
*dev
, unsigned int pipe
)
286 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
287 unsigned long irqflags
;
289 /* Prevent vblank irq processing while disabling vblank irqs,
290 * so no updates of timestamps or count can happen after we've
291 * disabled. Needed to prevent races in case of delayed irq's.
293 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
296 * Only disable vblank interrupts if they're enabled. This avoids
297 * calling the ->disable_vblank() operation in atomic context with the
298 * hardware potentially runtime suspended.
300 if (vblank
->enabled
) {
301 dev
->driver
->disable_vblank(dev
, pipe
);
302 vblank
->enabled
= false;
306 * Always update the count and timestamp to maintain the
307 * appearance that the counter has been ticking all along until
308 * this time. This makes the count account for the entire time
309 * between drm_crtc_vblank_on() and drm_crtc_vblank_off().
311 drm_update_vblank_count(dev
, pipe
, 0);
313 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
316 static void vblank_disable_fn(unsigned long arg
)
318 struct drm_vblank_crtc
*vblank
= (void *)arg
;
319 struct drm_device
*dev
= vblank
->dev
;
320 unsigned int pipe
= vblank
->pipe
;
321 unsigned long irqflags
;
323 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
324 if (atomic_read(&vblank
->refcount
) == 0 && vblank
->enabled
) {
325 DRM_DEBUG("disabling vblank on crtc %u\n", pipe
);
326 vblank_disable_and_save(dev
, pipe
);
328 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
332 * drm_vblank_cleanup - cleanup vblank support
335 * This function cleans up any resources allocated in drm_vblank_init.
337 void drm_vblank_cleanup(struct drm_device
*dev
)
341 /* Bail if the driver didn't call drm_vblank_init() */
342 if (dev
->num_crtcs
== 0)
345 for (pipe
= 0; pipe
< dev
->num_crtcs
; pipe
++) {
346 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
348 WARN_ON(vblank
->enabled
&&
349 drm_core_check_feature(dev
, DRIVER_MODESET
));
351 del_timer_sync(&vblank
->disable_timer
);
358 EXPORT_SYMBOL(drm_vblank_cleanup
);
361 * drm_vblank_init - initialize vblank support
363 * @num_crtcs: number of CRTCs supported by @dev
365 * This function initializes vblank support for @num_crtcs display pipelines.
368 * Zero on success or a negative error code on failure.
370 int drm_vblank_init(struct drm_device
*dev
, unsigned int num_crtcs
)
375 spin_lock_init(&dev
->vbl_lock
);
376 spin_lock_init(&dev
->vblank_time_lock
);
378 dev
->num_crtcs
= num_crtcs
;
380 dev
->vblank
= kcalloc(num_crtcs
, sizeof(*dev
->vblank
), GFP_KERNEL
);
384 for (i
= 0; i
< num_crtcs
; i
++) {
385 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
389 init_waitqueue_head(&vblank
->queue
);
390 setup_timer(&vblank
->disable_timer
, vblank_disable_fn
,
391 (unsigned long)vblank
);
392 seqlock_init(&vblank
->seqlock
);
395 DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
397 /* Driver specific high-precision vblank timestamping supported? */
398 if (dev
->driver
->get_vblank_timestamp
)
399 DRM_INFO("Driver supports precise vblank timestamp query.\n");
401 DRM_INFO("No driver support for vblank timestamp query.\n");
403 /* Must have precise timestamping for reliable vblank instant disable */
404 if (dev
->vblank_disable_immediate
&& !dev
->driver
->get_vblank_timestamp
) {
405 dev
->vblank_disable_immediate
= false;
406 DRM_INFO("Setting vblank_disable_immediate to false because "
407 "get_vblank_timestamp == NULL\n");
416 EXPORT_SYMBOL(drm_vblank_init
);
418 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
420 struct drm_device
*dev
= cookie
;
422 if (dev
->driver
->vgaarb_irq
) {
423 dev
->driver
->vgaarb_irq(dev
, state
);
427 if (!dev
->irq_enabled
)
431 if (dev
->driver
->irq_uninstall
)
432 dev
->driver
->irq_uninstall(dev
);
434 if (dev
->driver
->irq_preinstall
)
435 dev
->driver
->irq_preinstall(dev
);
436 if (dev
->driver
->irq_postinstall
)
437 dev
->driver
->irq_postinstall(dev
);
442 * drm_irq_install - install IRQ handler
444 * @irq: IRQ number to install the handler for
446 * Initializes the IRQ related data. Installs the handler, calling the driver
447 * irq_preinstall() and irq_postinstall() functions before and after the
450 * This is the simplified helper interface provided for drivers with no special
451 * needs. Drivers which need to install interrupt handlers for multiple
452 * interrupts must instead set drm_device->irq_enabled to signal the DRM core
453 * that vblank interrupts are available.
456 * Zero on success or a negative error code on failure.
458 int drm_irq_install(struct drm_device
*dev
, int irq
)
461 unsigned long sh_flags
= 0;
463 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
469 /* Driver must have been initialized */
470 if (!dev
->dev_private
)
473 if (dev
->irq_enabled
)
475 dev
->irq_enabled
= true;
477 DRM_DEBUG("irq=%d\n", irq
);
479 /* Before installing handler */
480 if (dev
->driver
->irq_preinstall
)
481 dev
->driver
->irq_preinstall(dev
);
483 /* Install handler */
484 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
485 sh_flags
= IRQF_SHARED
;
487 ret
= request_irq(irq
, dev
->driver
->irq_handler
,
488 sh_flags
, dev
->driver
->name
, dev
);
491 dev
->irq_enabled
= false;
495 if (drm_core_check_feature(dev
, DRIVER_LEGACY
))
496 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
498 /* After installing handler */
499 if (dev
->driver
->irq_postinstall
)
500 ret
= dev
->driver
->irq_postinstall(dev
);
503 dev
->irq_enabled
= false;
504 if (drm_core_check_feature(dev
, DRIVER_LEGACY
))
505 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
513 EXPORT_SYMBOL(drm_irq_install
);
516 * drm_irq_uninstall - uninstall the IRQ handler
519 * Calls the driver's irq_uninstall() function and unregisters the IRQ handler.
520 * This should only be called by drivers which used drm_irq_install() to set up
521 * their interrupt handler. Other drivers must only reset
522 * drm_device->irq_enabled to false.
524 * Note that for kernel modesetting drivers it is a bug if this function fails.
525 * The sanity checks are only to catch buggy user modesetting drivers which call
526 * the same function through an ioctl.
529 * Zero on success or a negative error code on failure.
531 int drm_irq_uninstall(struct drm_device
*dev
)
533 unsigned long irqflags
;
537 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
540 irq_enabled
= dev
->irq_enabled
;
541 dev
->irq_enabled
= false;
544 * Wake up any waiters so they don't hang. This is just to paper over
545 * issues for UMS drivers which aren't in full control of their
546 * vblank/irq handling. KMS drivers must ensure that vblanks are all
547 * disabled when uninstalling the irq handler.
549 if (dev
->num_crtcs
) {
550 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
551 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
552 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[i
];
554 if (!vblank
->enabled
)
557 WARN_ON(drm_core_check_feature(dev
, DRIVER_MODESET
));
559 vblank_disable_and_save(dev
, i
);
560 wake_up(&vblank
->queue
);
562 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
568 DRM_DEBUG("irq=%d\n", dev
->irq
);
570 if (drm_core_check_feature(dev
, DRIVER_LEGACY
))
571 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
573 if (dev
->driver
->irq_uninstall
)
574 dev
->driver
->irq_uninstall(dev
);
576 free_irq(dev
->irq
, dev
);
580 EXPORT_SYMBOL(drm_irq_uninstall
);
585 * \param inode device inode.
586 * \param file_priv DRM file private.
587 * \param cmd command.
588 * \param arg user argument, pointing to a drm_control structure.
589 * \return zero on success or a negative number on failure.
591 * Calls irq_install() or irq_uninstall() according to \p arg.
593 int drm_control(struct drm_device
*dev
, void *data
,
594 struct drm_file
*file_priv
)
596 struct drm_control
*ctl
= data
;
599 /* if we haven't irq we fallback for compatibility reasons -
600 * this used to be a separate function in drm_dma.h
603 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
605 if (!drm_core_check_feature(dev
, DRIVER_LEGACY
))
607 /* UMS was only ever supported on pci devices. */
608 if (WARN_ON(!dev
->pdev
))
612 case DRM_INST_HANDLER
:
613 irq
= dev
->pdev
->irq
;
615 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
618 mutex_lock(&dev
->struct_mutex
);
619 ret
= drm_irq_install(dev
, irq
);
620 mutex_unlock(&dev
->struct_mutex
);
623 case DRM_UNINST_HANDLER
:
624 mutex_lock(&dev
->struct_mutex
);
625 ret
= drm_irq_uninstall(dev
);
626 mutex_unlock(&dev
->struct_mutex
);
635 * drm_calc_timestamping_constants - calculate vblank timestamp constants
636 * @crtc: drm_crtc whose timestamp constants should be updated.
637 * @mode: display mode containing the scanout timings
639 * Calculate and store various constants which are later
640 * needed by vblank and swap-completion timestamping, e.g,
641 * by drm_calc_vbltimestamp_from_scanoutpos(). They are
642 * derived from CRTC's true scanout timing, so they take
643 * things like panel scaling or other adjustments into account.
645 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
,
646 const struct drm_display_mode
*mode
)
648 struct drm_device
*dev
= crtc
->dev
;
649 unsigned int pipe
= drm_crtc_index(crtc
);
650 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
651 int linedur_ns
= 0, framedur_ns
= 0;
652 int dotclock
= mode
->crtc_clock
;
657 if (WARN_ON(pipe
>= dev
->num_crtcs
))
660 /* Valid dotclock? */
662 int frame_size
= mode
->crtc_htotal
* mode
->crtc_vtotal
;
665 * Convert scanline length in pixels and video
666 * dot clock to line duration and frame duration
669 linedur_ns
= div_u64((u64
) mode
->crtc_htotal
* 1000000, dotclock
);
670 framedur_ns
= div_u64((u64
) frame_size
* 1000000, dotclock
);
673 * Fields of interlaced scanout modes are only half a frame duration.
675 if (mode
->flags
& DRM_MODE_FLAG_INTERLACE
)
678 DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n",
681 vblank
->linedur_ns
= linedur_ns
;
682 vblank
->framedur_ns
= framedur_ns
;
684 DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
685 crtc
->base
.id
, mode
->crtc_htotal
,
686 mode
->crtc_vtotal
, mode
->crtc_vdisplay
);
687 DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n",
688 crtc
->base
.id
, dotclock
, framedur_ns
, linedur_ns
);
690 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
693 * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper
695 * @pipe: index of CRTC whose vblank timestamp to retrieve
696 * @max_error: Desired maximum allowable error in timestamps (nanosecs)
697 * On return contains true maximum error of timestamp
698 * @vblank_time: Pointer to struct timeval which should receive the timestamp
699 * @flags: Flags to pass to driver:
701 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
702 * @mode: mode which defines the scanout timings
704 * Implements calculation of exact vblank timestamps from given drm_display_mode
705 * timings and current video scanout position of a CRTC. This can be called from
706 * within get_vblank_timestamp() implementation of a kms driver to implement the
707 * actual timestamping.
709 * Should return timestamps conforming to the OML_sync_control OpenML
710 * extension specification. The timestamp corresponds to the end of
711 * the vblank interval, aka start of scanout of topmost-leftmost display
712 * pixel in the following video frame.
714 * Requires support for optional dev->driver->get_scanout_position()
715 * in kms driver, plus a bit of setup code to provide a drm_display_mode
716 * that corresponds to the true scanout timing.
718 * The current implementation only handles standard video modes. It
719 * returns as no operation if a doublescan or interlaced video mode is
720 * active. Higher level code is expected to handle this.
723 * Negative value on error, failure or if not supported in current
726 * -EINVAL Invalid CRTC.
727 * -EAGAIN Temporary unavailable, e.g., called before initial modeset.
728 * -ENOTSUPP Function not supported in current display mode.
729 * -EIO Failed, e.g., due to failed scanout position query.
731 * Returns or'ed positive status flags on success:
733 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
734 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
737 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
,
740 struct timeval
*vblank_time
,
742 const struct drm_display_mode
*mode
)
744 struct timeval tv_etime
;
745 ktime_t stime
, etime
;
746 unsigned int vbl_status
;
747 int ret
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
749 int delta_ns
, duration_ns
;
751 if (pipe
>= dev
->num_crtcs
) {
752 DRM_ERROR("Invalid crtc %u\n", pipe
);
756 /* Scanout position query not supported? Should not happen. */
757 if (!dev
->driver
->get_scanout_position
) {
758 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
762 /* If mode timing undefined, just return as no-op:
763 * Happens during initial modesetting of a crtc.
765 if (mode
->crtc_clock
== 0) {
766 DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe
);
770 /* Get current scanout position with system timestamp.
771 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
772 * if single query takes longer than max_error nanoseconds.
774 * This guarantees a tight bound on maximum error if
775 * code gets preempted or delayed for some reason.
777 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
779 * Get vertical and horizontal scanout position vpos, hpos,
780 * and bounding timestamps stime, etime, pre/post query.
782 vbl_status
= dev
->driver
->get_scanout_position(dev
, pipe
, flags
,
787 /* Return as no-op if scanout query unsupported or failed. */
788 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
789 DRM_DEBUG("crtc %u : scanoutpos query failed [0x%x].\n",
794 /* Compute uncertainty in timestamp of scanout position query. */
795 duration_ns
= ktime_to_ns(etime
) - ktime_to_ns(stime
);
797 /* Accept result with < max_error nsecs timing uncertainty. */
798 if (duration_ns
<= *max_error
)
802 /* Noisy system timing? */
803 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
804 DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n",
805 pipe
, duration_ns
/1000, *max_error
/1000, i
);
808 /* Return upper bound of timestamp precision error. */
809 *max_error
= duration_ns
;
811 /* Check if in vblank area:
812 * vpos is >=0 in video scanout area, but negative
813 * within vblank area, counting down the number of lines until
816 if (vbl_status
& DRM_SCANOUTPOS_IN_VBLANK
)
817 ret
|= DRM_VBLANKTIME_IN_VBLANK
;
819 /* Convert scanout position into elapsed time at raw_time query
820 * since start of scanout at first display scanline. delta_ns
821 * can be negative if start of scanout hasn't happened yet.
823 delta_ns
= div_s64(1000000LL * (vpos
* mode
->crtc_htotal
+ hpos
),
826 if (!drm_timestamp_monotonic
)
827 etime
= ktime_mono_to_real(etime
);
829 /* save this only for debugging purposes */
830 tv_etime
= ktime_to_timeval(etime
);
831 /* Subtract time delta from raw timestamp to get final
832 * vblank_time timestamp for end of vblank.
834 etime
= ktime_sub_ns(etime
, delta_ns
);
835 *vblank_time
= ktime_to_timeval(etime
);
837 DRM_DEBUG_VBL("crtc %u : v 0x%x p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
838 pipe
, vbl_status
, hpos
, vpos
,
839 (long)tv_etime
.tv_sec
, (long)tv_etime
.tv_usec
,
840 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
841 duration_ns
/1000, i
);
845 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
847 static struct timeval
get_drm_timestamp(void)
851 now
= drm_timestamp_monotonic
? ktime_get() : ktime_get_real();
852 return ktime_to_timeval(now
);
856 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
859 * @pipe: index of CRTC whose vblank timestamp to retrieve
860 * @tvblank: Pointer to target struct timeval which should receive the timestamp
861 * @flags: Flags to pass to driver:
863 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl IRQ handler
865 * Fetches the system timestamp corresponding to the time of the most recent
866 * vblank interval on specified CRTC. May call into kms-driver to
867 * compute the timestamp with a high-precision GPU specific method.
869 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
870 * call, i.e., it isn't very precisely locked to the true vblank.
873 * True if timestamp is considered to be very precise, false otherwise.
876 drm_get_last_vbltimestamp(struct drm_device
*dev
, unsigned int pipe
,
877 struct timeval
*tvblank
, unsigned flags
)
881 /* Define requested maximum error on timestamps (nanoseconds). */
882 int max_error
= (int) drm_timestamp_precision
* 1000;
884 /* Query driver if possible and precision timestamping enabled. */
885 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
886 ret
= dev
->driver
->get_vblank_timestamp(dev
, pipe
, &max_error
,
892 /* GPU high precision timestamp query unsupported or failed.
893 * Return current monotonic/gettimeofday timestamp as best estimate.
895 *tvblank
= get_drm_timestamp();
901 * drm_crtc_vblank_count - retrieve "cooked" vblank counter value
902 * @crtc: which counter to retrieve
904 * Fetches the "cooked" vblank count value that represents the number of
905 * vblank events since the system was booted, including lost events due to
906 * modesetting activity.
909 * The software vblank counter.
911 u32
drm_crtc_vblank_count(struct drm_crtc
*crtc
)
913 return drm_vblank_count(crtc
->dev
, drm_crtc_index(crtc
));
915 EXPORT_SYMBOL(drm_crtc_vblank_count
);
918 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the
919 * system timestamp corresponding to that vblank counter value.
921 * @pipe: index of CRTC whose counter to retrieve
922 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
924 * Fetches the "cooked" vblank count value that represents the number of
925 * vblank events since the system was booted, including lost events due to
926 * modesetting activity. Returns corresponding system timestamp of the time
927 * of the vblank interval that corresponds to the current vblank counter value.
929 * This is the legacy version of drm_crtc_vblank_count_and_time().
931 static u32
drm_vblank_count_and_time(struct drm_device
*dev
, unsigned int pipe
,
932 struct timeval
*vblanktime
)
934 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
938 if (WARN_ON(pipe
>= dev
->num_crtcs
)) {
939 *vblanktime
= (struct timeval
) { 0 };
944 seq
= read_seqbegin(&vblank
->seqlock
);
945 vblank_count
= vblank
->count
;
946 *vblanktime
= vblank
->time
;
947 } while (read_seqretry(&vblank
->seqlock
, seq
));
953 * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value
954 * and the system timestamp corresponding to that vblank counter value
955 * @crtc: which counter to retrieve
956 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
958 * Fetches the "cooked" vblank count value that represents the number of
959 * vblank events since the system was booted, including lost events due to
960 * modesetting activity. Returns corresponding system timestamp of the time
961 * of the vblank interval that corresponds to the current vblank counter value.
963 u32
drm_crtc_vblank_count_and_time(struct drm_crtc
*crtc
,
964 struct timeval
*vblanktime
)
966 return drm_vblank_count_and_time(crtc
->dev
, drm_crtc_index(crtc
),
969 EXPORT_SYMBOL(drm_crtc_vblank_count_and_time
);
971 static void send_vblank_event(struct drm_device
*dev
,
972 struct drm_pending_vblank_event
*e
,
973 unsigned long seq
, struct timeval
*now
)
975 e
->event
.sequence
= seq
;
976 e
->event
.tv_sec
= now
->tv_sec
;
977 e
->event
.tv_usec
= now
->tv_usec
;
979 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
982 drm_send_event_locked(dev
, &e
->base
);
986 * drm_crtc_arm_vblank_event - arm vblank event after pageflip
987 * @crtc: the source CRTC of the vblank event
988 * @e: the event to send
990 * A lot of drivers need to generate vblank events for the very next vblank
991 * interrupt. For example when the page flip interrupt happens when the page
992 * flip gets armed, but not when it actually executes within the next vblank
993 * period. This helper function implements exactly the required vblank arming
996 * NOTE: Drivers using this to send out the event in struct &drm_crtc_state
997 * as part of an atomic commit must ensure that the next vblank happens at
998 * exactly the same time as the atomic commit is committed to the hardware. This
999 * function itself does **not** protect again the next vblank interrupt racing
1000 * with either this function call or the atomic commit operation. A possible
1001 * sequence could be:
1003 * 1. Driver commits new hardware state into vblank-synchronized registers.
1004 * 2. A vblank happens, committing the hardware state. Also the corresponding
1005 * vblank interrupt is fired off and fully processed by the interrupt
1007 * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event().
1008 * 4. The event is only send out for the next vblank, which is wrong.
1010 * An equivalent race can happen when the driver calls
1011 * drm_crtc_arm_vblank_event() before writing out the new hardware state.
1013 * The only way to make this work safely is to prevent the vblank from firing
1014 * (and the hardware from committing anything else) until the entire atomic
1015 * commit sequence has run to completion. If the hardware does not have such a
1016 * feature (e.g. using a "go" bit), then it is unsafe to use this functions.
1017 * Instead drivers need to manually send out the event from their interrupt
1018 * handler by calling drm_crtc_send_vblank_event() and make sure that there's no
1019 * possible race with the hardware committing the atomic update.
1021 * Caller must hold event lock. Caller must also hold a vblank reference for
1022 * the event @e, which will be dropped when the next vblank arrives.
1024 void drm_crtc_arm_vblank_event(struct drm_crtc
*crtc
,
1025 struct drm_pending_vblank_event
*e
)
1027 struct drm_device
*dev
= crtc
->dev
;
1028 unsigned int pipe
= drm_crtc_index(crtc
);
1030 assert_spin_locked(&dev
->event_lock
);
1033 e
->event
.sequence
= drm_vblank_count(dev
, pipe
);
1034 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1036 EXPORT_SYMBOL(drm_crtc_arm_vblank_event
);
1039 * drm_crtc_send_vblank_event - helper to send vblank event after pageflip
1040 * @crtc: the source CRTC of the vblank event
1041 * @e: the event to send
1043 * Updates sequence # and timestamp on event for the most recently processed
1044 * vblank, and sends it to userspace. Caller must hold event lock.
1046 * See drm_crtc_arm_vblank_event() for a helper which can be used in certain
1047 * situation, especially to send out events for atomic commit operations.
1049 void drm_crtc_send_vblank_event(struct drm_crtc
*crtc
,
1050 struct drm_pending_vblank_event
*e
)
1052 struct drm_device
*dev
= crtc
->dev
;
1053 unsigned int seq
, pipe
= drm_crtc_index(crtc
);
1056 if (dev
->num_crtcs
> 0) {
1057 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1061 now
= get_drm_timestamp();
1064 send_vblank_event(dev
, e
, seq
, &now
);
1066 EXPORT_SYMBOL(drm_crtc_send_vblank_event
);
1069 * drm_vblank_enable - enable the vblank interrupt on a CRTC
1074 * Zero on success or a negative error code on failure.
1076 static int drm_vblank_enable(struct drm_device
*dev
, unsigned int pipe
)
1078 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1081 assert_spin_locked(&dev
->vbl_lock
);
1083 spin_lock(&dev
->vblank_time_lock
);
1085 if (!vblank
->enabled
) {
1087 * Enable vblank irqs under vblank_time_lock protection.
1088 * All vblank count & timestamp updates are held off
1089 * until we are done reinitializing master counter and
1090 * timestamps. Filtercode in drm_handle_vblank() will
1091 * prevent double-accounting of same vblank interval.
1093 ret
= dev
->driver
->enable_vblank(dev
, pipe
);
1094 DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe
, ret
);
1096 atomic_dec(&vblank
->refcount
);
1098 vblank
->enabled
= true;
1099 drm_update_vblank_count(dev
, pipe
, 0);
1103 spin_unlock(&dev
->vblank_time_lock
);
1109 * drm_vblank_get - get a reference count on vblank events
1111 * @pipe: index of CRTC to own
1113 * Acquire a reference count on vblank events to avoid having them disabled
1116 * This is the legacy version of drm_crtc_vblank_get().
1119 * Zero on success or a negative error code on failure.
1121 static int drm_vblank_get(struct drm_device
*dev
, unsigned int pipe
)
1123 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1124 unsigned long irqflags
;
1127 if (!dev
->num_crtcs
)
1130 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1133 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1134 /* Going from 0->1 means we have to enable interrupts again */
1135 if (atomic_add_return(1, &vblank
->refcount
) == 1) {
1136 ret
= drm_vblank_enable(dev
, pipe
);
1138 if (!vblank
->enabled
) {
1139 atomic_dec(&vblank
->refcount
);
1143 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1149 * drm_crtc_vblank_get - get a reference count on vblank events
1150 * @crtc: which CRTC to own
1152 * Acquire a reference count on vblank events to avoid having them disabled
1156 * Zero on success or a negative error code on failure.
1158 int drm_crtc_vblank_get(struct drm_crtc
*crtc
)
1160 return drm_vblank_get(crtc
->dev
, drm_crtc_index(crtc
));
1162 EXPORT_SYMBOL(drm_crtc_vblank_get
);
1165 * drm_vblank_put - release ownership of vblank events
1167 * @pipe: index of CRTC to release
1169 * Release ownership of a given vblank counter, turning off interrupts
1170 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1172 * This is the legacy version of drm_crtc_vblank_put().
1174 static void drm_vblank_put(struct drm_device
*dev
, unsigned int pipe
)
1176 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1178 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1181 if (WARN_ON(atomic_read(&vblank
->refcount
) == 0))
1184 /* Last user schedules interrupt disable */
1185 if (atomic_dec_and_test(&vblank
->refcount
)) {
1186 if (drm_vblank_offdelay
== 0)
1188 else if (dev
->vblank_disable_immediate
|| drm_vblank_offdelay
< 0)
1189 vblank_disable_fn((unsigned long)vblank
);
1191 mod_timer(&vblank
->disable_timer
,
1192 jiffies
+ ((drm_vblank_offdelay
* HZ
)/1000));
1197 * drm_crtc_vblank_put - give up ownership of vblank events
1198 * @crtc: which counter to give up
1200 * Release ownership of a given vblank counter, turning off interrupts
1201 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
1203 void drm_crtc_vblank_put(struct drm_crtc
*crtc
)
1205 drm_vblank_put(crtc
->dev
, drm_crtc_index(crtc
));
1207 EXPORT_SYMBOL(drm_crtc_vblank_put
);
1210 * drm_wait_one_vblank - wait for one vblank
1214 * This waits for one vblank to pass on @pipe, using the irq driver interfaces.
1215 * It is a failure to call this when the vblank irq for @pipe is disabled, e.g.
1216 * due to lack of driver support or because the crtc is off.
1218 void drm_wait_one_vblank(struct drm_device
*dev
, unsigned int pipe
)
1220 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1224 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1227 ret
= drm_vblank_get(dev
, pipe
);
1228 if (WARN(ret
, "vblank not available on crtc %i, ret=%i\n", pipe
, ret
))
1231 last
= drm_vblank_count(dev
, pipe
);
1233 ret
= wait_event_timeout(vblank
->queue
,
1234 last
!= drm_vblank_count(dev
, pipe
),
1235 msecs_to_jiffies(100));
1237 WARN(ret
== 0, "vblank wait timed out on crtc %i\n", pipe
);
1239 drm_vblank_put(dev
, pipe
);
1241 EXPORT_SYMBOL(drm_wait_one_vblank
);
1244 * drm_crtc_wait_one_vblank - wait for one vblank
1247 * This waits for one vblank to pass on @crtc, using the irq driver interfaces.
1248 * It is a failure to call this when the vblank irq for @crtc is disabled, e.g.
1249 * due to lack of driver support or because the crtc is off.
1251 void drm_crtc_wait_one_vblank(struct drm_crtc
*crtc
)
1253 drm_wait_one_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1255 EXPORT_SYMBOL(drm_crtc_wait_one_vblank
);
1258 * drm_crtc_vblank_off - disable vblank events on a CRTC
1259 * @crtc: CRTC in question
1261 * Drivers can use this function to shut down the vblank interrupt handling when
1262 * disabling a crtc. This function ensures that the latest vblank frame count is
1263 * stored so that drm_vblank_on can restore it again.
1265 * Drivers must use this function when the hardware vblank counter can get
1266 * reset, e.g. when suspending.
1268 void drm_crtc_vblank_off(struct drm_crtc
*crtc
)
1270 struct drm_device
*dev
= crtc
->dev
;
1271 unsigned int pipe
= drm_crtc_index(crtc
);
1272 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1273 struct drm_pending_vblank_event
*e
, *t
;
1275 unsigned long irqflags
;
1278 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1281 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1283 spin_lock(&dev
->vbl_lock
);
1284 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1285 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1287 /* Avoid redundant vblank disables without previous
1288 * drm_crtc_vblank_on(). */
1289 if (drm_core_check_feature(dev
, DRIVER_ATOMIC
) || !vblank
->inmodeset
)
1290 vblank_disable_and_save(dev
, pipe
);
1292 wake_up(&vblank
->queue
);
1295 * Prevent subsequent drm_vblank_get() from re-enabling
1296 * the vblank interrupt by bumping the refcount.
1298 if (!vblank
->inmodeset
) {
1299 atomic_inc(&vblank
->refcount
);
1300 vblank
->inmodeset
= 1;
1302 spin_unlock(&dev
->vbl_lock
);
1304 /* Send any queued vblank events, lest the natives grow disquiet */
1305 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1307 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1308 if (e
->pipe
!= pipe
)
1310 DRM_DEBUG("Sending premature vblank event on disable: "
1311 "wanted %u, current %u\n",
1312 e
->event
.sequence
, seq
);
1313 list_del(&e
->base
.link
);
1314 drm_vblank_put(dev
, pipe
);
1315 send_vblank_event(dev
, e
, seq
, &now
);
1317 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1319 EXPORT_SYMBOL(drm_crtc_vblank_off
);
1322 * drm_crtc_vblank_reset - reset vblank state to off on a CRTC
1323 * @crtc: CRTC in question
1325 * Drivers can use this function to reset the vblank state to off at load time.
1326 * Drivers should use this together with the drm_crtc_vblank_off() and
1327 * drm_crtc_vblank_on() functions. The difference compared to
1328 * drm_crtc_vblank_off() is that this function doesn't save the vblank counter
1329 * and hence doesn't need to call any driver hooks.
1331 void drm_crtc_vblank_reset(struct drm_crtc
*crtc
)
1333 struct drm_device
*dev
= crtc
->dev
;
1334 unsigned long irqflags
;
1335 unsigned int pipe
= drm_crtc_index(crtc
);
1336 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1338 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1340 * Prevent subsequent drm_vblank_get() from enabling the vblank
1341 * interrupt by bumping the refcount.
1343 if (!vblank
->inmodeset
) {
1344 atomic_inc(&vblank
->refcount
);
1345 vblank
->inmodeset
= 1;
1347 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1349 WARN_ON(!list_empty(&dev
->vblank_event_list
));
1351 EXPORT_SYMBOL(drm_crtc_vblank_reset
);
1354 * drm_crtc_vblank_on - enable vblank events on a CRTC
1355 * @crtc: CRTC in question
1357 * This functions restores the vblank interrupt state captured with
1358 * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and
1359 * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called
1360 * in driver load code to reflect the current hardware state of the crtc.
1362 void drm_crtc_vblank_on(struct drm_crtc
*crtc
)
1364 struct drm_device
*dev
= crtc
->dev
;
1365 unsigned int pipe
= drm_crtc_index(crtc
);
1366 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1367 unsigned long irqflags
;
1369 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1372 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1373 DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n",
1374 pipe
, vblank
->enabled
, vblank
->inmodeset
);
1376 /* Drop our private "prevent drm_vblank_get" refcount */
1377 if (vblank
->inmodeset
) {
1378 atomic_dec(&vblank
->refcount
);
1379 vblank
->inmodeset
= 0;
1382 drm_reset_vblank_timestamp(dev
, pipe
);
1385 * re-enable interrupts if there are users left, or the
1386 * user wishes vblank interrupts to be enabled all the time.
1388 if (atomic_read(&vblank
->refcount
) != 0 || drm_vblank_offdelay
== 0)
1389 WARN_ON(drm_vblank_enable(dev
, pipe
));
1390 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1392 EXPORT_SYMBOL(drm_crtc_vblank_on
);
1394 static void drm_legacy_vblank_pre_modeset(struct drm_device
*dev
,
1397 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1399 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1400 if (!dev
->num_crtcs
)
1403 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1407 * To avoid all the problems that might happen if interrupts
1408 * were enabled/disabled around or between these calls, we just
1409 * have the kernel take a reference on the CRTC (just once though
1410 * to avoid corrupting the count if multiple, mismatch calls occur),
1411 * so that interrupts remain enabled in the interim.
1413 if (!vblank
->inmodeset
) {
1414 vblank
->inmodeset
= 0x1;
1415 if (drm_vblank_get(dev
, pipe
) == 0)
1416 vblank
->inmodeset
|= 0x2;
1420 static void drm_legacy_vblank_post_modeset(struct drm_device
*dev
,
1423 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1424 unsigned long irqflags
;
1426 /* vblank is not initialized (IRQ not installed ?), or has been freed */
1427 if (!dev
->num_crtcs
)
1430 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1433 if (vblank
->inmodeset
) {
1434 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1435 drm_reset_vblank_timestamp(dev
, pipe
);
1436 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1438 if (vblank
->inmodeset
& 0x2)
1439 drm_vblank_put(dev
, pipe
);
1441 vblank
->inmodeset
= 0;
1446 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1447 * @DRM_IOCTL_ARGS: standard ioctl arguments
1449 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1450 * ioctls around modesetting so that any lost vblank events are accounted for.
1452 * Generally the counter will reset across mode sets. If interrupts are
1453 * enabled around this call, we don't have to do anything since the counter
1454 * will have already been incremented.
1456 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1457 struct drm_file
*file_priv
)
1459 struct drm_modeset_ctl
*modeset
= data
;
1462 /* If drm_vblank_init() hasn't been called yet, just no-op */
1463 if (!dev
->num_crtcs
)
1466 /* KMS drivers handle this internally */
1467 if (!drm_core_check_feature(dev
, DRIVER_LEGACY
))
1470 pipe
= modeset
->crtc
;
1471 if (pipe
>= dev
->num_crtcs
)
1474 switch (modeset
->cmd
) {
1475 case _DRM_PRE_MODESET
:
1476 drm_legacy_vblank_pre_modeset(dev
, pipe
);
1478 case _DRM_POST_MODESET
:
1479 drm_legacy_vblank_post_modeset(dev
, pipe
);
1488 static int drm_queue_vblank_event(struct drm_device
*dev
, unsigned int pipe
,
1489 union drm_wait_vblank
*vblwait
,
1490 struct drm_file
*file_priv
)
1492 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1493 struct drm_pending_vblank_event
*e
;
1495 unsigned long flags
;
1499 e
= kzalloc(sizeof(*e
), GFP_KERNEL
);
1506 e
->base
.pid
= current
->pid
;
1507 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1508 e
->event
.base
.length
= sizeof(e
->event
);
1509 e
->event
.user_data
= vblwait
->request
.signal
;
1511 spin_lock_irqsave(&dev
->event_lock
, flags
);
1514 * drm_crtc_vblank_off() might have been called after we called
1515 * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the
1516 * vblank disable, so no need for further locking. The reference from
1517 * drm_vblank_get() protects against vblank disable from another source.
1519 if (!vblank
->enabled
) {
1524 ret
= drm_event_reserve_init_locked(dev
, file_priv
, &e
->base
,
1530 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1532 DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n",
1533 vblwait
->request
.sequence
, seq
, pipe
);
1535 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1536 vblwait
->request
.sequence
);
1538 e
->event
.sequence
= vblwait
->request
.sequence
;
1539 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1540 drm_vblank_put(dev
, pipe
);
1541 send_vblank_event(dev
, e
, seq
, &now
);
1542 vblwait
->reply
.sequence
= seq
;
1544 /* drm_handle_vblank_events will call drm_vblank_put */
1545 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1546 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1549 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1554 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1557 drm_vblank_put(dev
, pipe
);
1564 * \param inode device inode.
1565 * \param file_priv DRM file private.
1566 * \param cmd command.
1567 * \param data user argument, pointing to a drm_wait_vblank structure.
1568 * \return zero on success or a negative number on failure.
1570 * This function enables the vblank interrupt on the pipe requested, then
1571 * sleeps waiting for the requested sequence number to occur, and drops
1572 * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that
1573 * after a timeout with no further vblank waits scheduled).
1575 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1576 struct drm_file
*file_priv
)
1578 struct drm_vblank_crtc
*vblank
;
1579 union drm_wait_vblank
*vblwait
= data
;
1581 unsigned int flags
, seq
, pipe
, high_pipe
;
1583 if (!dev
->irq_enabled
)
1586 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1589 if (vblwait
->request
.type
&
1590 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1591 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1592 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1593 vblwait
->request
.type
,
1594 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1595 _DRM_VBLANK_HIGH_CRTC_MASK
));
1599 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1600 high_pipe
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1602 pipe
= high_pipe
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1604 pipe
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1605 if (pipe
>= dev
->num_crtcs
)
1608 vblank
= &dev
->vblank
[pipe
];
1610 ret
= drm_vblank_get(dev
, pipe
);
1612 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1615 seq
= drm_vblank_count(dev
, pipe
);
1617 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1618 case _DRM_VBLANK_RELATIVE
:
1619 vblwait
->request
.sequence
+= seq
;
1620 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1621 case _DRM_VBLANK_ABSOLUTE
:
1628 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1629 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1630 vblwait
->request
.sequence
= seq
+ 1;
1633 if (flags
& _DRM_VBLANK_EVENT
) {
1634 /* must hold on to the vblank ref until the event fires
1635 * drm_vblank_put will be called asynchronously
1637 return drm_queue_vblank_event(dev
, pipe
, vblwait
, file_priv
);
1640 DRM_DEBUG("waiting on vblank count %u, crtc %u\n",
1641 vblwait
->request
.sequence
, pipe
);
1642 DRM_WAIT_ON(ret
, vblank
->queue
, 3 * HZ
,
1643 (((drm_vblank_count(dev
, pipe
) -
1644 vblwait
->request
.sequence
) <= (1 << 23)) ||
1646 !dev
->irq_enabled
));
1648 if (ret
!= -EINTR
) {
1651 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1652 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1653 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1655 DRM_DEBUG("returning %u to client\n",
1656 vblwait
->reply
.sequence
);
1658 DRM_DEBUG("vblank wait interrupted by signal\n");
1662 drm_vblank_put(dev
, pipe
);
1666 static void drm_handle_vblank_events(struct drm_device
*dev
, unsigned int pipe
)
1668 struct drm_pending_vblank_event
*e
, *t
;
1672 assert_spin_locked(&dev
->event_lock
);
1674 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1676 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1677 if (e
->pipe
!= pipe
)
1679 if ((seq
- e
->event
.sequence
) > (1<<23))
1682 DRM_DEBUG("vblank event on %u, current %u\n",
1683 e
->event
.sequence
, seq
);
1685 list_del(&e
->base
.link
);
1686 drm_vblank_put(dev
, pipe
);
1687 send_vblank_event(dev
, e
, seq
, &now
);
1690 trace_drm_vblank_event(pipe
, seq
);
1694 * drm_handle_vblank - handle a vblank event
1696 * @pipe: index of CRTC where this event occurred
1698 * Drivers should call this routine in their vblank interrupt handlers to
1699 * update the vblank counter and send any signals that may be pending.
1701 * This is the legacy version of drm_crtc_handle_vblank().
1703 bool drm_handle_vblank(struct drm_device
*dev
, unsigned int pipe
)
1705 struct drm_vblank_crtc
*vblank
= &dev
->vblank
[pipe
];
1706 unsigned long irqflags
;
1708 if (WARN_ON_ONCE(!dev
->num_crtcs
))
1711 if (WARN_ON(pipe
>= dev
->num_crtcs
))
1714 spin_lock_irqsave(&dev
->event_lock
, irqflags
);
1716 /* Need timestamp lock to prevent concurrent execution with
1717 * vblank enable/disable, as this would cause inconsistent
1718 * or corrupted timestamps and vblank counts.
1720 spin_lock(&dev
->vblank_time_lock
);
1722 /* Vblank irq handling disabled. Nothing to do. */
1723 if (!vblank
->enabled
) {
1724 spin_unlock(&dev
->vblank_time_lock
);
1725 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1729 drm_update_vblank_count(dev
, pipe
, DRM_CALLED_FROM_VBLIRQ
);
1731 spin_unlock(&dev
->vblank_time_lock
);
1733 wake_up(&vblank
->queue
);
1734 drm_handle_vblank_events(dev
, pipe
);
1736 spin_unlock_irqrestore(&dev
->event_lock
, irqflags
);
1740 EXPORT_SYMBOL(drm_handle_vblank
);
1743 * drm_crtc_handle_vblank - handle a vblank event
1744 * @crtc: where this event occurred
1746 * Drivers should call this routine in their vblank interrupt handlers to
1747 * update the vblank counter and send any signals that may be pending.
1749 * This is the native KMS version of drm_handle_vblank().
1752 * True if the event was successfully handled, false on failure.
1754 bool drm_crtc_handle_vblank(struct drm_crtc
*crtc
)
1756 return drm_handle_vblank(crtc
->dev
, drm_crtc_index(crtc
));
1758 EXPORT_SYMBOL(drm_crtc_handle_vblank
);
1761 * drm_vblank_no_hw_counter - "No hw counter" implementation of .get_vblank_counter()
1763 * @pipe: CRTC for which to read the counter
1765 * Drivers can plug this into the .get_vblank_counter() function if
1766 * there is no useable hardware frame counter available.
1771 u32
drm_vblank_no_hw_counter(struct drm_device
*dev
, unsigned int pipe
)
1773 WARN_ON_ONCE(dev
->max_vblank_count
!= 0);
1776 EXPORT_SYMBOL(drm_vblank_no_hw_counter
);