5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
10 * Created: Fri Mar 19 14:30:16 1999 by faith@valinux.com
12 * Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
37 #include "drm_trace.h"
39 #include <linux/interrupt.h> /* For task queue support */
40 #include <linux/slab.h>
42 #include <linux/vgaarb.h>
43 #include <linux/export.h>
45 /* Access macro for slots in vblank timestamp ringbuffer. */
46 #define vblanktimestamp(dev, crtc, count) ( \
47 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
48 ((count) % DRM_VBLANKTIME_RBSIZE)])
50 /* Retry timestamp calculation up to 3 times to satisfy
51 * drm_timestamp_precision before giving up.
53 #define DRM_TIMESTAMP_MAXRETRIES 3
55 /* Threshold in nanoseconds for detection of redundant
56 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
58 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
61 * Get interrupt from bus id.
63 * \param inode device inode.
64 * \param file_priv DRM file private.
66 * \param arg user argument, pointing to a drm_irq_busid structure.
67 * \return zero on success or a negative number on failure.
69 * Finds the PCI device with the specified bus id and gets its IRQ number.
70 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
71 * to that of the device that this DRM instance attached to.
73 int drm_irq_by_busid(struct drm_device
*dev
, void *data
,
74 struct drm_file
*file_priv
)
76 struct drm_irq_busid
*p
= data
;
78 if (!dev
->driver
->bus
->irq_by_busid
)
81 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
84 return dev
->driver
->bus
->irq_by_busid(dev
, p
);
88 * Clear vblank timestamp buffer for a crtc.
90 static void clear_vblank_timestamps(struct drm_device
*dev
, int crtc
)
92 memset(&dev
->_vblank_time
[crtc
* DRM_VBLANKTIME_RBSIZE
], 0,
93 DRM_VBLANKTIME_RBSIZE
* sizeof(struct timeval
));
97 * Disable vblank irq's on crtc, make sure that last vblank count
98 * of hardware and corresponding consistent software vblank counter
99 * are preserved, even if there are any spurious vblank irq's after
102 static void vblank_disable_and_save(struct drm_device
*dev
, int crtc
)
104 unsigned long irqflags
;
108 struct timeval tvblank
;
110 /* Prevent vblank irq processing while disabling vblank irqs,
111 * so no updates of timestamps or count can happen after we've
112 * disabled. Needed to prevent races in case of delayed irq's.
113 * Disable preemption, so vblank_time_lock is held as short as
114 * possible, even under a kernel with PREEMPT_RT patches.
117 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
119 dev
->driver
->disable_vblank(dev
, crtc
);
120 dev
->vblank_enabled
[crtc
] = 0;
122 /* No further vblank irq's will be processed after
123 * this point. Get current hardware vblank count and
124 * vblank timestamp, repeat until they are consistent.
126 * FIXME: There is still a race condition here and in
127 * drm_update_vblank_count() which can cause off-by-one
128 * reinitialization of software vblank counter. If gpu
129 * vblank counter doesn't increment exactly at the leading
130 * edge of a vblank interval, then we can lose 1 count if
131 * we happen to execute between start of vblank and the
132 * delayed gpu counter increment.
135 dev
->last_vblank
[crtc
] = dev
->driver
->get_vblank_counter(dev
, crtc
);
136 vblrc
= drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, 0);
137 } while (dev
->last_vblank
[crtc
] != dev
->driver
->get_vblank_counter(dev
, crtc
));
139 /* Compute time difference to stored timestamp of last vblank
140 * as updated by last invocation of drm_handle_vblank() in vblank irq.
142 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
143 diff_ns
= timeval_to_ns(&tvblank
) -
144 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
146 /* If there is at least 1 msec difference between the last stored
147 * timestamp and tvblank, then we are currently executing our
148 * disable inside a new vblank interval, the tvblank timestamp
149 * corresponds to this new vblank interval and the irq handler
150 * for this vblank didn't run yet and won't run due to our disable.
151 * Therefore we need to do the job of drm_handle_vblank() and
152 * increment the vblank counter by one to account for this vblank.
154 * Skip this step if there isn't any high precision timestamp
155 * available. In that case we can't account for this and just
158 if ((vblrc
> 0) && (abs64(diff_ns
) > 1000000)) {
159 atomic_inc(&dev
->_vblank_count
[crtc
]);
160 smp_mb__after_atomic_inc();
163 /* Invalidate all timestamps while vblank irq's are off. */
164 clear_vblank_timestamps(dev
, crtc
);
166 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
170 static void vblank_disable_fn(unsigned long arg
)
172 struct drm_device
*dev
= (struct drm_device
*)arg
;
173 unsigned long irqflags
;
176 if (!dev
->vblank_disable_allowed
)
179 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
180 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
181 if (atomic_read(&dev
->vblank_refcount
[i
]) == 0 &&
182 dev
->vblank_enabled
[i
]) {
183 DRM_DEBUG("disabling vblank on crtc %d\n", i
);
184 vblank_disable_and_save(dev
, i
);
186 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
190 void drm_vblank_cleanup(struct drm_device
*dev
)
192 /* Bail if the driver didn't call drm_vblank_init() */
193 if (dev
->num_crtcs
== 0)
196 del_timer(&dev
->vblank_disable_timer
);
198 vblank_disable_fn((unsigned long)dev
);
200 kfree(dev
->vbl_queue
);
201 kfree(dev
->_vblank_count
);
202 kfree(dev
->vblank_refcount
);
203 kfree(dev
->vblank_enabled
);
204 kfree(dev
->last_vblank
);
205 kfree(dev
->last_vblank_wait
);
206 kfree(dev
->vblank_inmodeset
);
207 kfree(dev
->_vblank_time
);
211 EXPORT_SYMBOL(drm_vblank_cleanup
);
213 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
215 int i
, ret
= -ENOMEM
;
217 setup_timer(&dev
->vblank_disable_timer
, vblank_disable_fn
,
219 spin_lock_init(&dev
->vbl_lock
);
220 spin_lock_init(&dev
->vblank_time_lock
);
222 dev
->num_crtcs
= num_crtcs
;
224 dev
->vbl_queue
= kmalloc(sizeof(wait_queue_head_t
) * num_crtcs
,
229 dev
->_vblank_count
= kmalloc(sizeof(atomic_t
) * num_crtcs
, GFP_KERNEL
);
230 if (!dev
->_vblank_count
)
233 dev
->vblank_refcount
= kmalloc(sizeof(atomic_t
) * num_crtcs
,
235 if (!dev
->vblank_refcount
)
238 dev
->vblank_enabled
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
239 if (!dev
->vblank_enabled
)
242 dev
->last_vblank
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
243 if (!dev
->last_vblank
)
246 dev
->last_vblank_wait
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
247 if (!dev
->last_vblank_wait
)
250 dev
->vblank_inmodeset
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
251 if (!dev
->vblank_inmodeset
)
254 dev
->_vblank_time
= kcalloc(num_crtcs
* DRM_VBLANKTIME_RBSIZE
,
255 sizeof(struct timeval
), GFP_KERNEL
);
256 if (!dev
->_vblank_time
)
259 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
261 /* Driver specific high-precision vblank timestamping supported? */
262 if (dev
->driver
->get_vblank_timestamp
)
263 DRM_INFO("Driver supports precise vblank timestamp query.\n");
265 DRM_INFO("No driver support for vblank timestamp query.\n");
267 /* Zero per-crtc vblank stuff */
268 for (i
= 0; i
< num_crtcs
; i
++) {
269 init_waitqueue_head(&dev
->vbl_queue
[i
]);
270 atomic_set(&dev
->_vblank_count
[i
], 0);
271 atomic_set(&dev
->vblank_refcount
[i
], 0);
274 dev
->vblank_disable_allowed
= 0;
278 drm_vblank_cleanup(dev
);
281 EXPORT_SYMBOL(drm_vblank_init
);
283 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
285 struct drm_device
*dev
= cookie
;
287 if (dev
->driver
->vgaarb_irq
) {
288 dev
->driver
->vgaarb_irq(dev
, state
);
292 if (!dev
->irq_enabled
)
296 if (dev
->driver
->irq_uninstall
)
297 dev
->driver
->irq_uninstall(dev
);
299 if (dev
->driver
->irq_preinstall
)
300 dev
->driver
->irq_preinstall(dev
);
301 if (dev
->driver
->irq_postinstall
)
302 dev
->driver
->irq_postinstall(dev
);
307 * Install IRQ handler.
309 * \param dev DRM device.
311 * Initializes the IRQ related data. Installs the handler, calling the driver
312 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
313 * before and after the installation.
315 int drm_irq_install(struct drm_device
*dev
)
318 unsigned long sh_flags
= 0;
321 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
324 if (drm_dev_to_irq(dev
) == 0)
327 mutex_lock(&dev
->struct_mutex
);
329 /* Driver must have been initialized */
330 if (!dev
->dev_private
) {
331 mutex_unlock(&dev
->struct_mutex
);
335 if (dev
->irq_enabled
) {
336 mutex_unlock(&dev
->struct_mutex
);
339 dev
->irq_enabled
= 1;
340 mutex_unlock(&dev
->struct_mutex
);
342 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
344 /* Before installing handler */
345 if (dev
->driver
->irq_preinstall
)
346 dev
->driver
->irq_preinstall(dev
);
348 /* Install handler */
349 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
350 sh_flags
= IRQF_SHARED
;
353 irqname
= dev
->devname
;
355 irqname
= dev
->driver
->name
;
357 ret
= request_irq(drm_dev_to_irq(dev
), dev
->driver
->irq_handler
,
358 sh_flags
, irqname
, dev
);
361 mutex_lock(&dev
->struct_mutex
);
362 dev
->irq_enabled
= 0;
363 mutex_unlock(&dev
->struct_mutex
);
367 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
368 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
370 /* After installing handler */
371 if (dev
->driver
->irq_postinstall
)
372 ret
= dev
->driver
->irq_postinstall(dev
);
375 mutex_lock(&dev
->struct_mutex
);
376 dev
->irq_enabled
= 0;
377 mutex_unlock(&dev
->struct_mutex
);
378 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
379 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
380 free_irq(drm_dev_to_irq(dev
), dev
);
385 EXPORT_SYMBOL(drm_irq_install
);
388 * Uninstall the IRQ handler.
390 * \param dev DRM device.
392 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
394 int drm_irq_uninstall(struct drm_device
*dev
)
396 unsigned long irqflags
;
399 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
402 mutex_lock(&dev
->struct_mutex
);
403 irq_enabled
= dev
->irq_enabled
;
404 dev
->irq_enabled
= 0;
405 mutex_unlock(&dev
->struct_mutex
);
408 * Wake up any waiters so they don't hang.
410 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
411 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
412 DRM_WAKEUP(&dev
->vbl_queue
[i
]);
413 dev
->vblank_enabled
[i
] = 0;
414 dev
->last_vblank
[i
] = dev
->driver
->get_vblank_counter(dev
, i
);
416 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
421 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
423 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
424 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
426 if (dev
->driver
->irq_uninstall
)
427 dev
->driver
->irq_uninstall(dev
);
429 free_irq(drm_dev_to_irq(dev
), dev
);
433 EXPORT_SYMBOL(drm_irq_uninstall
);
438 * \param inode device inode.
439 * \param file_priv DRM file private.
440 * \param cmd command.
441 * \param arg user argument, pointing to a drm_control structure.
442 * \return zero on success or a negative number on failure.
444 * Calls irq_install() or irq_uninstall() according to \p arg.
446 int drm_control(struct drm_device
*dev
, void *data
,
447 struct drm_file
*file_priv
)
449 struct drm_control
*ctl
= data
;
451 /* if we haven't irq we fallback for compatibility reasons -
452 * this used to be a separate function in drm_dma.h
457 case DRM_INST_HANDLER
:
458 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
460 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
462 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
463 ctl
->irq
!= drm_dev_to_irq(dev
))
465 return drm_irq_install(dev
);
466 case DRM_UNINST_HANDLER
:
467 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
469 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
471 return drm_irq_uninstall(dev
);
478 * drm_calc_timestamping_constants - Calculate and
479 * store various constants which are later needed by
480 * vblank and swap-completion timestamping, e.g, by
481 * drm_calc_vbltimestamp_from_scanoutpos().
482 * They are derived from crtc's true scanout timing,
483 * so they take things like panel scaling or other
484 * adjustments into account.
486 * @crtc drm_crtc whose timestamp constants should be updated.
489 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
491 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
494 /* Dot clock in Hz: */
495 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
497 /* Fields of interlaced scanout modes are only halve a frame duration.
498 * Double the dotclock to get halve the frame-/line-/pixelduration.
500 if (crtc
->hwmode
.flags
& DRM_MODE_FLAG_INTERLACE
)
503 /* Valid dotclock? */
505 /* Convert scanline length in pixels and video dot clock to
506 * line duration, frame duration and pixel duration in
509 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
510 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
511 1000000000), dotclock
);
512 framedur_ns
= (s64
) crtc
->hwmode
.crtc_vtotal
* linedur_ns
;
514 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
517 crtc
->pixeldur_ns
= pixeldur_ns
;
518 crtc
->linedur_ns
= linedur_ns
;
519 crtc
->framedur_ns
= framedur_ns
;
521 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
522 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
523 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
524 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
525 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
526 (int) linedur_ns
, (int) pixeldur_ns
);
528 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
531 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
532 * drivers. Implements calculation of exact vblank timestamps from
533 * given drm_display_mode timings and current video scanout position
534 * of a crtc. This can be called from within get_vblank_timestamp()
535 * implementation of a kms driver to implement the actual timestamping.
537 * Should return timestamps conforming to the OML_sync_control OpenML
538 * extension specification. The timestamp corresponds to the end of
539 * the vblank interval, aka start of scanout of topmost-leftmost display
540 * pixel in the following video frame.
542 * Requires support for optional dev->driver->get_scanout_position()
543 * in kms driver, plus a bit of setup code to provide a drm_display_mode
544 * that corresponds to the true scanout timing.
546 * The current implementation only handles standard video modes. It
547 * returns as no operation if a doublescan or interlaced video mode is
548 * active. Higher level code is expected to handle this.
551 * @crtc: Which crtc's vblank timestamp to retrieve.
552 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
553 * On return contains true maximum error of timestamp.
554 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
555 * @flags: Flags to pass to driver:
557 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
558 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
560 * Returns negative value on error, failure or if not supported in current
563 * -EINVAL - Invalid crtc.
564 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
565 * -ENOTSUPP - Function not supported in current display mode.
566 * -EIO - Failed, e.g., due to failed scanout position query.
568 * Returns or'ed positive status flags on success:
570 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
571 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
574 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
576 struct timeval
*vblank_time
,
578 struct drm_crtc
*refcrtc
)
580 struct timeval stime
, raw_time
;
581 struct drm_display_mode
*mode
;
582 int vbl_status
, vtotal
, vdisplay
;
584 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
587 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
588 DRM_ERROR("Invalid crtc %d\n", crtc
);
592 /* Scanout position query not supported? Should not happen. */
593 if (!dev
->driver
->get_scanout_position
) {
594 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
598 mode
= &refcrtc
->hwmode
;
599 vtotal
= mode
->crtc_vtotal
;
600 vdisplay
= mode
->crtc_vdisplay
;
602 /* Durations of frames, lines, pixels in nanoseconds. */
603 framedur_ns
= refcrtc
->framedur_ns
;
604 linedur_ns
= refcrtc
->linedur_ns
;
605 pixeldur_ns
= refcrtc
->pixeldur_ns
;
607 /* If mode timing undefined, just return as no-op:
608 * Happens during initial modesetting of a crtc.
610 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
611 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
615 /* Get current scanout position with system timestamp.
616 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
617 * if single query takes longer than max_error nanoseconds.
619 * This guarantees a tight bound on maximum error if
620 * code gets preempted or delayed for some reason.
622 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
623 /* Disable preemption to make it very likely to
624 * succeed in the first iteration even on PREEMPT_RT kernel.
628 /* Get system timestamp before query. */
629 do_gettimeofday(&stime
);
631 /* Get vertical and horizontal scanout pos. vpos, hpos. */
632 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
634 /* Get system timestamp after query. */
635 do_gettimeofday(&raw_time
);
639 /* Return as no-op if scanout query unsupported or failed. */
640 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
641 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
646 duration_ns
= timeval_to_ns(&raw_time
) - timeval_to_ns(&stime
);
648 /* Accept result with < max_error nsecs timing uncertainty. */
649 if (duration_ns
<= (s64
) *max_error
)
653 /* Noisy system timing? */
654 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
655 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
656 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
659 /* Return upper bound of timestamp precision error. */
660 *max_error
= (int) duration_ns
;
662 /* Check if in vblank area:
663 * vpos is >=0 in video scanout area, but negative
664 * within vblank area, counting down the number of lines until
667 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
669 /* Convert scanout position into elapsed time at raw_time query
670 * since start of scanout at first display scanline. delta_ns
671 * can be negative if start of scanout hasn't happened yet.
673 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
675 /* Is vpos outside nominal vblank area, but less than
676 * 1/100 of a frame height away from start of vblank?
677 * If so, assume this isn't a massively delayed vblank
678 * interrupt, but a vblank interrupt that fired a few
679 * microseconds before true start of vblank. Compensate
680 * by adding a full frame duration to the final timestamp.
681 * Happens, e.g., on ATI R500, R600.
683 * We only do this if DRM_CALLED_FROM_VBLIRQ.
685 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
686 ((vdisplay
- vpos
) < vtotal
/ 100)) {
687 delta_ns
= delta_ns
- framedur_ns
;
689 /* Signal this correction as "applied". */
693 /* Subtract time delta from raw timestamp to get final
694 * vblank_time timestamp for end of vblank.
696 *vblank_time
= ns_to_timeval(timeval_to_ns(&raw_time
) - delta_ns
);
698 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n",
699 crtc
, (int)vbl_status
, hpos
, vpos
,
700 (long)raw_time
.tv_sec
, (long)raw_time
.tv_usec
,
701 (long)vblank_time
->tv_sec
, (long)vblank_time
->tv_usec
,
702 (int)duration_ns
/1000, i
);
704 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
706 vbl_status
|= DRM_VBLANKTIME_INVBL
;
710 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
713 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
717 * @crtc: which crtc's vblank timestamp to retrieve
718 * @tvblank: Pointer to target struct timeval which should receive the timestamp
719 * @flags: Flags to pass to driver:
721 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
723 * Fetches the system timestamp corresponding to the time of the most recent
724 * vblank interval on specified crtc. May call into kms-driver to
725 * compute the timestamp with a high-precision GPU specific method.
727 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
728 * call, i.e., it isn't very precisely locked to the true vblank.
730 * Returns non-zero if timestamp is considered to be very precise.
732 u32
drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
733 struct timeval
*tvblank
, unsigned flags
)
737 /* Define requested maximum error on timestamps (nanoseconds). */
738 int max_error
= (int) drm_timestamp_precision
* 1000;
740 /* Query driver if possible and precision timestamping enabled. */
741 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
742 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
748 /* GPU high precision timestamp query unsupported or failed.
749 * Return gettimeofday timestamp as best estimate.
751 do_gettimeofday(tvblank
);
755 EXPORT_SYMBOL(drm_get_last_vbltimestamp
);
758 * drm_vblank_count - retrieve "cooked" vblank counter value
760 * @crtc: which counter to retrieve
762 * Fetches the "cooked" vblank count value that represents the number of
763 * vblank events since the system was booted, including lost events due to
764 * modesetting activity.
766 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
768 return atomic_read(&dev
->_vblank_count
[crtc
]);
770 EXPORT_SYMBOL(drm_vblank_count
);
773 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
774 * and the system timestamp corresponding to that vblank counter value.
777 * @crtc: which counter to retrieve
778 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
780 * Fetches the "cooked" vblank count value that represents the number of
781 * vblank events since the system was booted, including lost events due to
782 * modesetting activity. Returns corresponding system timestamp of the time
783 * of the vblank interval that corresponds to the current value vblank counter
786 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
787 struct timeval
*vblanktime
)
791 /* Read timestamp from slot of _vblank_time ringbuffer
792 * that corresponds to current vblank count. Retry if
793 * count has incremented during readout. This works like
797 cur_vblank
= atomic_read(&dev
->_vblank_count
[crtc
]);
798 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
800 } while (cur_vblank
!= atomic_read(&dev
->_vblank_count
[crtc
]));
804 EXPORT_SYMBOL(drm_vblank_count_and_time
);
807 * drm_update_vblank_count - update the master vblank counter
809 * @crtc: counter to update
811 * Call back into the driver to update the appropriate vblank counter
812 * (specified by @crtc). Deal with wraparound, if it occurred, and
813 * update the last read value so we can deal with wraparound on the next
816 * Only necessary when going from off->on, to account for frames we
817 * didn't get an interrupt for.
819 * Note: caller must hold dev->vbl_lock since this reads & writes
820 * device vblank fields.
822 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
824 u32 cur_vblank
, diff
, tslot
, rc
;
825 struct timeval t_vblank
;
828 * Interrupts were disabled prior to this call, so deal with counter
830 * NOTE! It's possible we lost a full dev->max_vblank_count events
831 * here if the register is small or we had vblank interrupts off for
834 * We repeat the hardware vblank counter & timestamp query until
835 * we get consistent results. This to prevent races between gpu
836 * updating its hardware counter while we are retrieving the
837 * corresponding vblank timestamp.
840 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
841 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
842 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
844 /* Deal with counter wrap */
845 diff
= cur_vblank
- dev
->last_vblank
[crtc
];
846 if (cur_vblank
< dev
->last_vblank
[crtc
]) {
847 diff
+= dev
->max_vblank_count
;
849 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
850 crtc
, dev
->last_vblank
[crtc
], cur_vblank
, diff
);
853 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
856 /* Reinitialize corresponding vblank timestamp if high-precision query
857 * available. Skip this step if query unsupported or failed. Will
858 * reinitialize delayed at next vblank interrupt in that case.
861 tslot
= atomic_read(&dev
->_vblank_count
[crtc
]) + diff
;
862 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
865 smp_mb__before_atomic_inc();
866 atomic_add(diff
, &dev
->_vblank_count
[crtc
]);
867 smp_mb__after_atomic_inc();
871 * drm_vblank_get - get a reference count on vblank events
873 * @crtc: which CRTC to own
875 * Acquire a reference count on vblank events to avoid having them disabled
879 * Zero on success, nonzero on failure.
881 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
883 unsigned long irqflags
, irqflags2
;
886 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
887 /* Going from 0->1 means we have to enable interrupts again */
888 if (atomic_add_return(1, &dev
->vblank_refcount
[crtc
]) == 1) {
889 /* Disable preemption while holding vblank_time_lock. Do
890 * it explicitely to guard against PREEMPT_RT kernel.
893 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags2
);
894 if (!dev
->vblank_enabled
[crtc
]) {
895 /* Enable vblank irqs under vblank_time_lock protection.
896 * All vblank count & timestamp updates are held off
897 * until we are done reinitializing master counter and
898 * timestamps. Filtercode in drm_handle_vblank() will
899 * prevent double-accounting of same vblank interval.
901 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
902 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
905 atomic_dec(&dev
->vblank_refcount
[crtc
]);
907 dev
->vblank_enabled
[crtc
] = 1;
908 drm_update_vblank_count(dev
, crtc
);
911 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags2
);
914 if (!dev
->vblank_enabled
[crtc
]) {
915 atomic_dec(&dev
->vblank_refcount
[crtc
]);
919 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
923 EXPORT_SYMBOL(drm_vblank_get
);
926 * drm_vblank_put - give up ownership of vblank events
928 * @crtc: which counter to give up
930 * Release ownership of a given vblank counter, turning off interrupts
931 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
933 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
935 BUG_ON(atomic_read(&dev
->vblank_refcount
[crtc
]) == 0);
937 /* Last user schedules interrupt disable */
938 if (atomic_dec_and_test(&dev
->vblank_refcount
[crtc
]) &&
939 (drm_vblank_offdelay
> 0))
940 mod_timer(&dev
->vblank_disable_timer
,
941 jiffies
+ ((drm_vblank_offdelay
* DRM_HZ
)/1000));
943 EXPORT_SYMBOL(drm_vblank_put
);
945 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
947 struct drm_pending_vblank_event
*e
, *t
;
949 unsigned long irqflags
;
952 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
953 vblank_disable_and_save(dev
, crtc
);
954 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
956 /* Send any queued vblank events, lest the natives grow disquiet */
957 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
958 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
961 DRM_DEBUG("Sending premature vblank event on disable: \
962 wanted %d, current %d\n",
963 e
->event
.sequence
, seq
);
965 e
->event
.sequence
= seq
;
966 e
->event
.tv_sec
= now
.tv_sec
;
967 e
->event
.tv_usec
= now
.tv_usec
;
968 drm_vblank_put(dev
, e
->pipe
);
969 list_move_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
970 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
971 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
975 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
977 EXPORT_SYMBOL(drm_vblank_off
);
980 * drm_vblank_pre_modeset - account for vblanks across mode sets
982 * @crtc: CRTC in question
983 * @post: post or pre mode set?
985 * Account for vblank events across mode setting events, which will likely
986 * reset the hardware frame counter.
988 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
990 /* vblank is not initialized (IRQ not installed ?) */
994 * To avoid all the problems that might happen if interrupts
995 * were enabled/disabled around or between these calls, we just
996 * have the kernel take a reference on the CRTC (just once though
997 * to avoid corrupting the count if multiple, mismatch calls occur),
998 * so that interrupts remain enabled in the interim.
1000 if (!dev
->vblank_inmodeset
[crtc
]) {
1001 dev
->vblank_inmodeset
[crtc
] = 0x1;
1002 if (drm_vblank_get(dev
, crtc
) == 0)
1003 dev
->vblank_inmodeset
[crtc
] |= 0x2;
1006 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
1008 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
1010 unsigned long irqflags
;
1012 if (dev
->vblank_inmodeset
[crtc
]) {
1013 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
1014 dev
->vblank_disable_allowed
= 1;
1015 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
1017 if (dev
->vblank_inmodeset
[crtc
] & 0x2)
1018 drm_vblank_put(dev
, crtc
);
1020 dev
->vblank_inmodeset
[crtc
] = 0;
1023 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1026 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1027 * @DRM_IOCTL_ARGS: standard ioctl arguments
1029 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1030 * ioctls around modesetting so that any lost vblank events are accounted for.
1032 * Generally the counter will reset across mode sets. If interrupts are
1033 * enabled around this call, we don't have to do anything since the counter
1034 * will have already been incremented.
1036 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1037 struct drm_file
*file_priv
)
1039 struct drm_modeset_ctl
*modeset
= data
;
1043 /* If drm_vblank_init() hasn't been called yet, just no-op */
1044 if (!dev
->num_crtcs
)
1047 crtc
= modeset
->crtc
;
1048 if (crtc
>= dev
->num_crtcs
) {
1053 switch (modeset
->cmd
) {
1054 case _DRM_PRE_MODESET
:
1055 drm_vblank_pre_modeset(dev
, crtc
);
1057 case _DRM_POST_MODESET
:
1058 drm_vblank_post_modeset(dev
, crtc
);
1069 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1070 union drm_wait_vblank
*vblwait
,
1071 struct drm_file
*file_priv
)
1073 struct drm_pending_vblank_event
*e
;
1075 unsigned long flags
;
1079 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1086 e
->base
.pid
= current
->pid
;
1087 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1088 e
->event
.base
.length
= sizeof e
->event
;
1089 e
->event
.user_data
= vblwait
->request
.signal
;
1090 e
->base
.event
= &e
->event
.base
;
1091 e
->base
.file_priv
= file_priv
;
1092 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1094 spin_lock_irqsave(&dev
->event_lock
, flags
);
1096 if (file_priv
->event_space
< sizeof e
->event
) {
1101 file_priv
->event_space
-= sizeof e
->event
;
1102 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1104 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1105 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1106 vblwait
->request
.sequence
= seq
+ 1;
1107 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1110 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1111 vblwait
->request
.sequence
, seq
, pipe
);
1113 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1114 vblwait
->request
.sequence
);
1116 e
->event
.sequence
= vblwait
->request
.sequence
;
1117 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1118 e
->event
.sequence
= seq
;
1119 e
->event
.tv_sec
= now
.tv_sec
;
1120 e
->event
.tv_usec
= now
.tv_usec
;
1121 drm_vblank_put(dev
, pipe
);
1122 list_add_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1123 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1124 vblwait
->reply
.sequence
= seq
;
1125 trace_drm_vblank_event_delivered(current
->pid
, pipe
,
1126 vblwait
->request
.sequence
);
1128 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1129 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1132 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1137 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1140 drm_vblank_put(dev
, pipe
);
1147 * \param inode device inode.
1148 * \param file_priv DRM file private.
1149 * \param cmd command.
1150 * \param data user argument, pointing to a drm_wait_vblank structure.
1151 * \return zero on success or a negative number on failure.
1153 * This function enables the vblank interrupt on the pipe requested, then
1154 * sleeps waiting for the requested sequence number to occur, and drops
1155 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1156 * after a timeout with no further vblank waits scheduled).
1158 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1159 struct drm_file
*file_priv
)
1161 union drm_wait_vblank
*vblwait
= data
;
1163 unsigned int flags
, seq
, crtc
, high_crtc
;
1165 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1168 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1171 if (vblwait
->request
.type
&
1172 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1173 _DRM_VBLANK_HIGH_CRTC_MASK
)) {
1174 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1175 vblwait
->request
.type
,
1176 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
|
1177 _DRM_VBLANK_HIGH_CRTC_MASK
));
1181 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1182 high_crtc
= (vblwait
->request
.type
& _DRM_VBLANK_HIGH_CRTC_MASK
);
1184 crtc
= high_crtc
>> _DRM_VBLANK_HIGH_CRTC_SHIFT
;
1186 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1187 if (crtc
>= dev
->num_crtcs
)
1190 ret
= drm_vblank_get(dev
, crtc
);
1192 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1195 seq
= drm_vblank_count(dev
, crtc
);
1197 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1198 case _DRM_VBLANK_RELATIVE
:
1199 vblwait
->request
.sequence
+= seq
;
1200 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1201 case _DRM_VBLANK_ABSOLUTE
:
1208 if (flags
& _DRM_VBLANK_EVENT
)
1209 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1211 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1212 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1213 vblwait
->request
.sequence
= seq
+ 1;
1216 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1217 vblwait
->request
.sequence
, crtc
);
1218 dev
->last_vblank_wait
[crtc
] = vblwait
->request
.sequence
;
1219 DRM_WAIT_ON(ret
, dev
->vbl_queue
[crtc
], 3 * DRM_HZ
,
1220 (((drm_vblank_count(dev
, crtc
) -
1221 vblwait
->request
.sequence
) <= (1 << 23)) ||
1222 !dev
->irq_enabled
));
1224 if (ret
!= -EINTR
) {
1227 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1228 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1229 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1231 DRM_DEBUG("returning %d to client\n",
1232 vblwait
->reply
.sequence
);
1234 DRM_DEBUG("vblank wait interrupted by signal\n");
1238 drm_vblank_put(dev
, crtc
);
1242 void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1244 struct drm_pending_vblank_event
*e
, *t
;
1246 unsigned long flags
;
1249 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1251 spin_lock_irqsave(&dev
->event_lock
, flags
);
1253 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1254 if (e
->pipe
!= crtc
)
1256 if ((seq
- e
->event
.sequence
) > (1<<23))
1259 DRM_DEBUG("vblank event on %d, current %d\n",
1260 e
->event
.sequence
, seq
);
1262 e
->event
.sequence
= seq
;
1263 e
->event
.tv_sec
= now
.tv_sec
;
1264 e
->event
.tv_usec
= now
.tv_usec
;
1265 drm_vblank_put(dev
, e
->pipe
);
1266 list_move_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1267 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1268 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1272 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1274 trace_drm_vblank_event(crtc
, seq
);
1278 * drm_handle_vblank - handle a vblank event
1280 * @crtc: where this event occurred
1282 * Drivers should call this routine in their vblank interrupt handlers to
1283 * update the vblank counter and send any signals that may be pending.
1285 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1289 struct timeval tvblank
;
1290 unsigned long irqflags
;
1292 if (!dev
->num_crtcs
)
1295 /* Need timestamp lock to prevent concurrent execution with
1296 * vblank enable/disable, as this would cause inconsistent
1297 * or corrupted timestamps and vblank counts.
1299 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1301 /* Vblank irq handling disabled. Nothing to do. */
1302 if (!dev
->vblank_enabled
[crtc
]) {
1303 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1307 /* Fetch corresponding timestamp for this vblank interval from
1308 * driver and store it in proper slot of timestamp ringbuffer.
1311 /* Get current timestamp and count. */
1312 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
1313 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1315 /* Compute time difference to timestamp of last vblank */
1316 diff_ns
= timeval_to_ns(&tvblank
) -
1317 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1319 /* Update vblank timestamp and count if at least
1320 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1321 * difference between last stored timestamp and current
1322 * timestamp. A smaller difference means basically
1323 * identical timestamps. Happens if this vblank has
1324 * been already processed and this is a redundant call,
1325 * e.g., due to spurious vblank interrupts. We need to
1326 * ignore those for accounting.
1328 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1329 /* Store new timestamp in ringbuffer. */
1330 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1332 /* Increment cooked vblank count. This also atomically commits
1333 * the timestamp computed above.
1335 smp_mb__before_atomic_inc();
1336 atomic_inc(&dev
->_vblank_count
[crtc
]);
1337 smp_mb__after_atomic_inc();
1339 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1340 crtc
, (int) diff_ns
);
1343 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
1344 drm_handle_vblank_events(dev
, crtc
);
1346 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1349 EXPORT_SYMBOL(drm_handle_vblank
);