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>
44 /* Access macro for slots in vblank timestamp ringbuffer. */
45 #define vblanktimestamp(dev, crtc, count) ( \
46 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \
47 ((count) % DRM_VBLANKTIME_RBSIZE)])
49 /* Retry timestamp calculation up to 3 times to satisfy
50 * drm_timestamp_precision before giving up.
52 #define DRM_TIMESTAMP_MAXRETRIES 3
54 /* Threshold in nanoseconds for detection of redundant
55 * vblank irq in drm_handle_vblank(). 1 msec should be ok.
57 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000
60 * Get interrupt from bus id.
62 * \param inode device inode.
63 * \param file_priv DRM file private.
65 * \param arg user argument, pointing to a drm_irq_busid structure.
66 * \return zero on success or a negative number on failure.
68 * Finds the PCI device with the specified bus id and gets its IRQ number.
69 * This IOCTL is deprecated, and will now return EINVAL for any busid not equal
70 * to that of the device that this DRM instance attached to.
72 int drm_irq_by_busid(struct drm_device
*dev
, void *data
,
73 struct drm_file
*file_priv
)
75 struct drm_irq_busid
*p
= data
;
77 if (!dev
->driver
->bus
->irq_by_busid
)
80 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
83 return dev
->driver
->bus
->irq_by_busid(dev
, p
);
87 * Clear vblank timestamp buffer for a crtc.
89 static void clear_vblank_timestamps(struct drm_device
*dev
, int crtc
)
91 memset(&dev
->_vblank_time
[crtc
* DRM_VBLANKTIME_RBSIZE
], 0,
92 DRM_VBLANKTIME_RBSIZE
* sizeof(struct timeval
));
96 * Disable vblank irq's on crtc, make sure that last vblank count
97 * of hardware and corresponding consistent software vblank counter
98 * are preserved, even if there are any spurious vblank irq's after
101 static void vblank_disable_and_save(struct drm_device
*dev
, int crtc
)
103 unsigned long irqflags
;
107 struct timeval tvblank
;
109 /* Prevent vblank irq processing while disabling vblank irqs,
110 * so no updates of timestamps or count can happen after we've
111 * disabled. Needed to prevent races in case of delayed irq's.
112 * Disable preemption, so vblank_time_lock is held as short as
113 * possible, even under a kernel with PREEMPT_RT patches.
116 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
118 dev
->driver
->disable_vblank(dev
, crtc
);
119 dev
->vblank_enabled
[crtc
] = 0;
121 /* No further vblank irq's will be processed after
122 * this point. Get current hardware vblank count and
123 * vblank timestamp, repeat until they are consistent.
125 * FIXME: There is still a race condition here and in
126 * drm_update_vblank_count() which can cause off-by-one
127 * reinitialization of software vblank counter. If gpu
128 * vblank counter doesn't increment exactly at the leading
129 * edge of a vblank interval, then we can lose 1 count if
130 * we happen to execute between start of vblank and the
131 * delayed gpu counter increment.
134 dev
->last_vblank
[crtc
] = dev
->driver
->get_vblank_counter(dev
, crtc
);
135 vblrc
= drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, 0);
136 } while (dev
->last_vblank
[crtc
] != dev
->driver
->get_vblank_counter(dev
, crtc
));
138 /* Compute time difference to stored timestamp of last vblank
139 * as updated by last invocation of drm_handle_vblank() in vblank irq.
141 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
142 diff_ns
= timeval_to_ns(&tvblank
) -
143 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
145 /* If there is at least 1 msec difference between the last stored
146 * timestamp and tvblank, then we are currently executing our
147 * disable inside a new vblank interval, the tvblank timestamp
148 * corresponds to this new vblank interval and the irq handler
149 * for this vblank didn't run yet and won't run due to our disable.
150 * Therefore we need to do the job of drm_handle_vblank() and
151 * increment the vblank counter by one to account for this vblank.
153 * Skip this step if there isn't any high precision timestamp
154 * available. In that case we can't account for this and just
157 if ((vblrc
> 0) && (abs(diff_ns
) > 1000000))
158 atomic_inc(&dev
->_vblank_count
[crtc
]);
160 /* Invalidate all timestamps while vblank irq's are off. */
161 clear_vblank_timestamps(dev
, crtc
);
163 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
167 static void vblank_disable_fn(unsigned long arg
)
169 struct drm_device
*dev
= (struct drm_device
*)arg
;
170 unsigned long irqflags
;
173 if (!dev
->vblank_disable_allowed
)
176 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
177 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
178 if (atomic_read(&dev
->vblank_refcount
[i
]) == 0 &&
179 dev
->vblank_enabled
[i
]) {
180 DRM_DEBUG("disabling vblank on crtc %d\n", i
);
181 vblank_disable_and_save(dev
, i
);
183 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
187 void drm_vblank_cleanup(struct drm_device
*dev
)
189 /* Bail if the driver didn't call drm_vblank_init() */
190 if (dev
->num_crtcs
== 0)
193 del_timer(&dev
->vblank_disable_timer
);
195 vblank_disable_fn((unsigned long)dev
);
197 kfree(dev
->vbl_queue
);
198 kfree(dev
->_vblank_count
);
199 kfree(dev
->vblank_refcount
);
200 kfree(dev
->vblank_enabled
);
201 kfree(dev
->last_vblank
);
202 kfree(dev
->last_vblank_wait
);
203 kfree(dev
->vblank_inmodeset
);
204 kfree(dev
->_vblank_time
);
208 EXPORT_SYMBOL(drm_vblank_cleanup
);
210 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
212 int i
, ret
= -ENOMEM
;
214 setup_timer(&dev
->vblank_disable_timer
, vblank_disable_fn
,
216 spin_lock_init(&dev
->vbl_lock
);
217 spin_lock_init(&dev
->vblank_time_lock
);
219 dev
->num_crtcs
= num_crtcs
;
221 dev
->vbl_queue
= kmalloc(sizeof(wait_queue_head_t
) * num_crtcs
,
226 dev
->_vblank_count
= kmalloc(sizeof(atomic_t
) * num_crtcs
, GFP_KERNEL
);
227 if (!dev
->_vblank_count
)
230 dev
->vblank_refcount
= kmalloc(sizeof(atomic_t
) * num_crtcs
,
232 if (!dev
->vblank_refcount
)
235 dev
->vblank_enabled
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
236 if (!dev
->vblank_enabled
)
239 dev
->last_vblank
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
240 if (!dev
->last_vblank
)
243 dev
->last_vblank_wait
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
244 if (!dev
->last_vblank_wait
)
247 dev
->vblank_inmodeset
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
248 if (!dev
->vblank_inmodeset
)
251 dev
->_vblank_time
= kcalloc(num_crtcs
* DRM_VBLANKTIME_RBSIZE
,
252 sizeof(struct timeval
), GFP_KERNEL
);
253 if (!dev
->_vblank_time
)
256 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
258 /* Driver specific high-precision vblank timestamping supported? */
259 if (dev
->driver
->get_vblank_timestamp
)
260 DRM_INFO("Driver supports precise vblank timestamp query.\n");
262 DRM_INFO("No driver support for vblank timestamp query.\n");
264 /* Zero per-crtc vblank stuff */
265 for (i
= 0; i
< num_crtcs
; i
++) {
266 init_waitqueue_head(&dev
->vbl_queue
[i
]);
267 atomic_set(&dev
->_vblank_count
[i
], 0);
268 atomic_set(&dev
->vblank_refcount
[i
], 0);
271 dev
->vblank_disable_allowed
= 0;
275 drm_vblank_cleanup(dev
);
278 EXPORT_SYMBOL(drm_vblank_init
);
280 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
282 struct drm_device
*dev
= cookie
;
284 if (dev
->driver
->vgaarb_irq
) {
285 dev
->driver
->vgaarb_irq(dev
, state
);
289 if (!dev
->irq_enabled
)
293 dev
->driver
->irq_uninstall(dev
);
295 dev
->driver
->irq_preinstall(dev
);
296 dev
->driver
->irq_postinstall(dev
);
301 * Install IRQ handler.
303 * \param dev DRM device.
305 * Initializes the IRQ related data. Installs the handler, calling the driver
306 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
307 * before and after the installation.
309 int drm_irq_install(struct drm_device
*dev
)
312 unsigned long sh_flags
= 0;
315 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
318 if (drm_dev_to_irq(dev
) == 0)
321 mutex_lock(&dev
->struct_mutex
);
323 /* Driver must have been initialized */
324 if (!dev
->dev_private
) {
325 mutex_unlock(&dev
->struct_mutex
);
329 if (dev
->irq_enabled
) {
330 mutex_unlock(&dev
->struct_mutex
);
333 dev
->irq_enabled
= 1;
334 mutex_unlock(&dev
->struct_mutex
);
336 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
338 /* Before installing handler */
339 dev
->driver
->irq_preinstall(dev
);
341 /* Install handler */
342 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
343 sh_flags
= IRQF_SHARED
;
346 irqname
= dev
->devname
;
348 irqname
= dev
->driver
->name
;
350 ret
= request_irq(drm_dev_to_irq(dev
), dev
->driver
->irq_handler
,
351 sh_flags
, irqname
, dev
);
354 mutex_lock(&dev
->struct_mutex
);
355 dev
->irq_enabled
= 0;
356 mutex_unlock(&dev
->struct_mutex
);
360 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
361 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
363 /* After installing handler */
364 ret
= dev
->driver
->irq_postinstall(dev
);
366 mutex_lock(&dev
->struct_mutex
);
367 dev
->irq_enabled
= 0;
368 mutex_unlock(&dev
->struct_mutex
);
373 EXPORT_SYMBOL(drm_irq_install
);
376 * Uninstall the IRQ handler.
378 * \param dev DRM device.
380 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
382 int drm_irq_uninstall(struct drm_device
*dev
)
384 unsigned long irqflags
;
387 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
390 mutex_lock(&dev
->struct_mutex
);
391 irq_enabled
= dev
->irq_enabled
;
392 dev
->irq_enabled
= 0;
393 mutex_unlock(&dev
->struct_mutex
);
396 * Wake up any waiters so they don't hang.
398 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
399 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
400 DRM_WAKEUP(&dev
->vbl_queue
[i
]);
401 dev
->vblank_enabled
[i
] = 0;
402 dev
->last_vblank
[i
] = dev
->driver
->get_vblank_counter(dev
, i
);
404 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
409 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
411 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
412 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
414 dev
->driver
->irq_uninstall(dev
);
416 free_irq(drm_dev_to_irq(dev
), dev
);
420 EXPORT_SYMBOL(drm_irq_uninstall
);
425 * \param inode device inode.
426 * \param file_priv DRM file private.
427 * \param cmd command.
428 * \param arg user argument, pointing to a drm_control structure.
429 * \return zero on success or a negative number on failure.
431 * Calls irq_install() or irq_uninstall() according to \p arg.
433 int drm_control(struct drm_device
*dev
, void *data
,
434 struct drm_file
*file_priv
)
436 struct drm_control
*ctl
= data
;
438 /* if we haven't irq we fallback for compatibility reasons -
439 * this used to be a separate function in drm_dma.h
444 case DRM_INST_HANDLER
:
445 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
447 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
449 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
450 ctl
->irq
!= drm_dev_to_irq(dev
))
452 return drm_irq_install(dev
);
453 case DRM_UNINST_HANDLER
:
454 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
456 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
458 return drm_irq_uninstall(dev
);
465 * drm_calc_timestamping_constants - Calculate and
466 * store various constants which are later needed by
467 * vblank and swap-completion timestamping, e.g, by
468 * drm_calc_vbltimestamp_from_scanoutpos().
469 * They are derived from crtc's true scanout timing,
470 * so they take things like panel scaling or other
471 * adjustments into account.
473 * @crtc drm_crtc whose timestamp constants should be updated.
476 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
478 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
481 /* Dot clock in Hz: */
482 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
484 /* Valid dotclock? */
486 /* Convert scanline length in pixels and video dot clock to
487 * line duration, frame duration and pixel duration in
490 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
491 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
492 1000000000), dotclock
);
493 framedur_ns
= (s64
) crtc
->hwmode
.crtc_vtotal
* linedur_ns
;
495 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
498 crtc
->pixeldur_ns
= pixeldur_ns
;
499 crtc
->linedur_ns
= linedur_ns
;
500 crtc
->framedur_ns
= framedur_ns
;
502 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
503 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
504 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
505 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
506 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
507 (int) linedur_ns
, (int) pixeldur_ns
);
509 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
512 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
513 * drivers. Implements calculation of exact vblank timestamps from
514 * given drm_display_mode timings and current video scanout position
515 * of a crtc. This can be called from within get_vblank_timestamp()
516 * implementation of a kms driver to implement the actual timestamping.
518 * Should return timestamps conforming to the OML_sync_control OpenML
519 * extension specification. The timestamp corresponds to the end of
520 * the vblank interval, aka start of scanout of topmost-leftmost display
521 * pixel in the following video frame.
523 * Requires support for optional dev->driver->get_scanout_position()
524 * in kms driver, plus a bit of setup code to provide a drm_display_mode
525 * that corresponds to the true scanout timing.
527 * The current implementation only handles standard video modes. It
528 * returns as no operation if a doublescan or interlaced video mode is
529 * active. Higher level code is expected to handle this.
532 * @crtc: Which crtc's vblank timestamp to retrieve.
533 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
534 * On return contains true maximum error of timestamp.
535 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
536 * @flags: Flags to pass to driver:
538 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
539 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
541 * Returns negative value on error, failure or if not supported in current
544 * -EINVAL - Invalid crtc.
545 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
546 * -ENOTSUPP - Function not supported in current display mode.
547 * -EIO - Failed, e.g., due to failed scanout position query.
549 * Returns or'ed positive status flags on success:
551 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
552 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
555 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
557 struct timeval
*vblank_time
,
559 struct drm_crtc
*refcrtc
)
561 struct timeval stime
, raw_time
;
562 struct drm_display_mode
*mode
;
563 int vbl_status
, vtotal
, vdisplay
;
565 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
568 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
569 DRM_ERROR("Invalid crtc %d\n", crtc
);
573 /* Scanout position query not supported? Should not happen. */
574 if (!dev
->driver
->get_scanout_position
) {
575 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
579 mode
= &refcrtc
->hwmode
;
580 vtotal
= mode
->crtc_vtotal
;
581 vdisplay
= mode
->crtc_vdisplay
;
583 /* Durations of frames, lines, pixels in nanoseconds. */
584 framedur_ns
= refcrtc
->framedur_ns
;
585 linedur_ns
= refcrtc
->linedur_ns
;
586 pixeldur_ns
= refcrtc
->pixeldur_ns
;
588 /* If mode timing undefined, just return as no-op:
589 * Happens during initial modesetting of a crtc.
591 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
592 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
596 /* Don't know yet how to handle interlaced or
597 * double scan modes. Just no-op for now.
599 if (mode
->flags
& (DRM_MODE_FLAG_INTERLACE
| DRM_MODE_FLAG_DBLSCAN
)) {
600 DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc
);
604 /* Get current scanout position with system timestamp.
605 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
606 * if single query takes longer than max_error nanoseconds.
608 * This guarantees a tight bound on maximum error if
609 * code gets preempted or delayed for some reason.
611 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
612 /* Disable preemption to make it very likely to
613 * succeed in the first iteration even on PREEMPT_RT kernel.
617 /* Get system timestamp before query. */
618 do_gettimeofday(&stime
);
620 /* Get vertical and horizontal scanout pos. vpos, hpos. */
621 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
623 /* Get system timestamp after query. */
624 do_gettimeofday(&raw_time
);
628 /* Return as no-op if scanout query unsupported or failed. */
629 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
630 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
635 duration_ns
= timeval_to_ns(&raw_time
) - timeval_to_ns(&stime
);
637 /* Accept result with < max_error nsecs timing uncertainty. */
638 if (duration_ns
<= (s64
) *max_error
)
642 /* Noisy system timing? */
643 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
644 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
645 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
648 /* Return upper bound of timestamp precision error. */
649 *max_error
= (int) duration_ns
;
651 /* Check if in vblank area:
652 * vpos is >=0 in video scanout area, but negative
653 * within vblank area, counting down the number of lines until
656 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
658 /* Convert scanout position into elapsed time at raw_time query
659 * since start of scanout at first display scanline. delta_ns
660 * can be negative if start of scanout hasn't happened yet.
662 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
664 /* Is vpos outside nominal vblank area, but less than
665 * 1/100 of a frame height away from start of vblank?
666 * If so, assume this isn't a massively delayed vblank
667 * interrupt, but a vblank interrupt that fired a few
668 * microseconds before true start of vblank. Compensate
669 * by adding a full frame duration to the final timestamp.
670 * Happens, e.g., on ATI R500, R600.
672 * We only do this if DRM_CALLED_FROM_VBLIRQ.
674 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
675 ((vdisplay
- vpos
) < vtotal
/ 100)) {
676 delta_ns
= delta_ns
- framedur_ns
;
678 /* Signal this correction as "applied". */
682 /* Subtract time delta from raw timestamp to get final
683 * vblank_time timestamp for end of vblank.
685 *vblank_time
= ns_to_timeval(timeval_to_ns(&raw_time
) - delta_ns
);
687 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %d.%d -> %d.%d [e %d us, %d rep]\n",
688 crtc
, (int) vbl_status
, hpos
, vpos
, raw_time
.tv_sec
,
689 raw_time
.tv_usec
, vblank_time
->tv_sec
, vblank_time
->tv_usec
,
690 (int) duration_ns
/1000, i
);
692 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
694 vbl_status
|= DRM_VBLANKTIME_INVBL
;
698 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
701 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
705 * @crtc: which crtc's vblank timestamp to retrieve
706 * @tvblank: Pointer to target struct timeval which should receive the timestamp
707 * @flags: Flags to pass to driver:
709 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
711 * Fetches the system timestamp corresponding to the time of the most recent
712 * vblank interval on specified crtc. May call into kms-driver to
713 * compute the timestamp with a high-precision GPU specific method.
715 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
716 * call, i.e., it isn't very precisely locked to the true vblank.
718 * Returns non-zero if timestamp is considered to be very precise.
720 u32
drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
721 struct timeval
*tvblank
, unsigned flags
)
725 /* Define requested maximum error on timestamps (nanoseconds). */
726 int max_error
= (int) drm_timestamp_precision
* 1000;
728 /* Query driver if possible and precision timestamping enabled. */
729 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
730 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
736 /* GPU high precision timestamp query unsupported or failed.
737 * Return gettimeofday timestamp as best estimate.
739 do_gettimeofday(tvblank
);
743 EXPORT_SYMBOL(drm_get_last_vbltimestamp
);
746 * drm_vblank_count - retrieve "cooked" vblank counter value
748 * @crtc: which counter to retrieve
750 * Fetches the "cooked" vblank count value that represents the number of
751 * vblank events since the system was booted, including lost events due to
752 * modesetting activity.
754 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
756 return atomic_read(&dev
->_vblank_count
[crtc
]);
758 EXPORT_SYMBOL(drm_vblank_count
);
761 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
762 * and the system timestamp corresponding to that vblank counter value.
765 * @crtc: which counter to retrieve
766 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
768 * Fetches the "cooked" vblank count value that represents the number of
769 * vblank events since the system was booted, including lost events due to
770 * modesetting activity. Returns corresponding system timestamp of the time
771 * of the vblank interval that corresponds to the current value vblank counter
774 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
775 struct timeval
*vblanktime
)
779 /* Read timestamp from slot of _vblank_time ringbuffer
780 * that corresponds to current vblank count. Retry if
781 * count has incremented during readout. This works like
785 cur_vblank
= atomic_read(&dev
->_vblank_count
[crtc
]);
786 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
788 } while (cur_vblank
!= atomic_read(&dev
->_vblank_count
[crtc
]));
792 EXPORT_SYMBOL(drm_vblank_count_and_time
);
795 * drm_update_vblank_count - update the master vblank counter
797 * @crtc: counter to update
799 * Call back into the driver to update the appropriate vblank counter
800 * (specified by @crtc). Deal with wraparound, if it occurred, and
801 * update the last read value so we can deal with wraparound on the next
804 * Only necessary when going from off->on, to account for frames we
805 * didn't get an interrupt for.
807 * Note: caller must hold dev->vbl_lock since this reads & writes
808 * device vblank fields.
810 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
812 u32 cur_vblank
, diff
, tslot
, rc
;
813 struct timeval t_vblank
;
816 * Interrupts were disabled prior to this call, so deal with counter
818 * NOTE! It's possible we lost a full dev->max_vblank_count events
819 * here if the register is small or we had vblank interrupts off for
822 * We repeat the hardware vblank counter & timestamp query until
823 * we get consistent results. This to prevent races between gpu
824 * updating its hardware counter while we are retrieving the
825 * corresponding vblank timestamp.
828 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
829 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
830 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
832 /* Deal with counter wrap */
833 diff
= cur_vblank
- dev
->last_vblank
[crtc
];
834 if (cur_vblank
< dev
->last_vblank
[crtc
]) {
835 diff
+= dev
->max_vblank_count
;
837 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
838 crtc
, dev
->last_vblank
[crtc
], cur_vblank
, diff
);
841 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
844 /* Reinitialize corresponding vblank timestamp if high-precision query
845 * available. Skip this step if query unsupported or failed. Will
846 * reinitialize delayed at next vblank interrupt in that case.
849 tslot
= atomic_read(&dev
->_vblank_count
[crtc
]) + diff
;
850 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
854 atomic_add(diff
, &dev
->_vblank_count
[crtc
]);
858 * drm_vblank_get - get a reference count on vblank events
860 * @crtc: which CRTC to own
862 * Acquire a reference count on vblank events to avoid having them disabled
866 * Zero on success, nonzero on failure.
868 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
870 unsigned long irqflags
, irqflags2
;
873 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
874 /* Going from 0->1 means we have to enable interrupts again */
875 if (atomic_add_return(1, &dev
->vblank_refcount
[crtc
]) == 1) {
876 /* Disable preemption while holding vblank_time_lock. Do
877 * it explicitely to guard against PREEMPT_RT kernel.
880 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags2
);
881 if (!dev
->vblank_enabled
[crtc
]) {
882 /* Enable vblank irqs under vblank_time_lock protection.
883 * All vblank count & timestamp updates are held off
884 * until we are done reinitializing master counter and
885 * timestamps. Filtercode in drm_handle_vblank() will
886 * prevent double-accounting of same vblank interval.
888 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
889 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
892 atomic_dec(&dev
->vblank_refcount
[crtc
]);
894 dev
->vblank_enabled
[crtc
] = 1;
895 drm_update_vblank_count(dev
, crtc
);
898 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags2
);
901 if (!dev
->vblank_enabled
[crtc
]) {
902 atomic_dec(&dev
->vblank_refcount
[crtc
]);
906 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
910 EXPORT_SYMBOL(drm_vblank_get
);
913 * drm_vblank_put - give up ownership of vblank events
915 * @crtc: which counter to give up
917 * Release ownership of a given vblank counter, turning off interrupts
918 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
920 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
922 BUG_ON(atomic_read(&dev
->vblank_refcount
[crtc
]) == 0);
924 /* Last user schedules interrupt disable */
925 if (atomic_dec_and_test(&dev
->vblank_refcount
[crtc
]) &&
926 (drm_vblank_offdelay
> 0))
927 mod_timer(&dev
->vblank_disable_timer
,
928 jiffies
+ ((drm_vblank_offdelay
* DRM_HZ
)/1000));
930 EXPORT_SYMBOL(drm_vblank_put
);
932 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
934 unsigned long irqflags
;
936 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
937 vblank_disable_and_save(dev
, crtc
);
938 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
939 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
941 EXPORT_SYMBOL(drm_vblank_off
);
944 * drm_vblank_pre_modeset - account for vblanks across mode sets
946 * @crtc: CRTC in question
947 * @post: post or pre mode set?
949 * Account for vblank events across mode setting events, which will likely
950 * reset the hardware frame counter.
952 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
954 /* vblank is not initialized (IRQ not installed ?) */
958 * To avoid all the problems that might happen if interrupts
959 * were enabled/disabled around or between these calls, we just
960 * have the kernel take a reference on the CRTC (just once though
961 * to avoid corrupting the count if multiple, mismatch calls occur),
962 * so that interrupts remain enabled in the interim.
964 if (!dev
->vblank_inmodeset
[crtc
]) {
965 dev
->vblank_inmodeset
[crtc
] = 0x1;
966 if (drm_vblank_get(dev
, crtc
) == 0)
967 dev
->vblank_inmodeset
[crtc
] |= 0x2;
970 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
972 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
974 unsigned long irqflags
;
976 if (dev
->vblank_inmodeset
[crtc
]) {
977 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
978 dev
->vblank_disable_allowed
= 1;
979 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
981 if (dev
->vblank_inmodeset
[crtc
] & 0x2)
982 drm_vblank_put(dev
, crtc
);
984 dev
->vblank_inmodeset
[crtc
] = 0;
987 EXPORT_SYMBOL(drm_vblank_post_modeset
);
990 * drm_modeset_ctl - handle vblank event counter changes across mode switch
991 * @DRM_IOCTL_ARGS: standard ioctl arguments
993 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
994 * ioctls around modesetting so that any lost vblank events are accounted for.
996 * Generally the counter will reset across mode sets. If interrupts are
997 * enabled around this call, we don't have to do anything since the counter
998 * will have already been incremented.
1000 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1001 struct drm_file
*file_priv
)
1003 struct drm_modeset_ctl
*modeset
= data
;
1006 /* If drm_vblank_init() hasn't been called yet, just no-op */
1007 if (!dev
->num_crtcs
)
1010 crtc
= modeset
->crtc
;
1011 if (crtc
>= dev
->num_crtcs
) {
1016 switch (modeset
->cmd
) {
1017 case _DRM_PRE_MODESET
:
1018 drm_vblank_pre_modeset(dev
, crtc
);
1020 case _DRM_POST_MODESET
:
1021 drm_vblank_post_modeset(dev
, crtc
);
1032 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1033 union drm_wait_vblank
*vblwait
,
1034 struct drm_file
*file_priv
)
1036 struct drm_pending_vblank_event
*e
;
1038 unsigned long flags
;
1042 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1049 e
->base
.pid
= current
->pid
;
1050 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1051 e
->event
.base
.length
= sizeof e
->event
;
1052 e
->event
.user_data
= vblwait
->request
.signal
;
1053 e
->base
.event
= &e
->event
.base
;
1054 e
->base
.file_priv
= file_priv
;
1055 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1057 spin_lock_irqsave(&dev
->event_lock
, flags
);
1059 if (file_priv
->event_space
< sizeof e
->event
) {
1064 file_priv
->event_space
-= sizeof e
->event
;
1065 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1067 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1068 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1069 vblwait
->request
.sequence
= seq
+ 1;
1070 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1073 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1074 vblwait
->request
.sequence
, seq
, pipe
);
1076 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1077 vblwait
->request
.sequence
);
1079 e
->event
.sequence
= vblwait
->request
.sequence
;
1080 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1081 e
->event
.sequence
= seq
;
1082 e
->event
.tv_sec
= now
.tv_sec
;
1083 e
->event
.tv_usec
= now
.tv_usec
;
1084 drm_vblank_put(dev
, pipe
);
1085 list_add_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1086 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1087 vblwait
->reply
.sequence
= seq
;
1088 trace_drm_vblank_event_delivered(current
->pid
, pipe
,
1089 vblwait
->request
.sequence
);
1091 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1092 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1095 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1100 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1103 drm_vblank_put(dev
, pipe
);
1110 * \param inode device inode.
1111 * \param file_priv DRM file private.
1112 * \param cmd command.
1113 * \param data user argument, pointing to a drm_wait_vblank structure.
1114 * \return zero on success or a negative number on failure.
1116 * This function enables the vblank interrupt on the pipe requested, then
1117 * sleeps waiting for the requested sequence number to occur, and drops
1118 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1119 * after a timeout with no further vblank waits scheduled).
1121 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1122 struct drm_file
*file_priv
)
1124 union drm_wait_vblank
*vblwait
= data
;
1126 unsigned int flags
, seq
, crtc
;
1128 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1131 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1134 if (vblwait
->request
.type
&
1135 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
)) {
1136 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1137 vblwait
->request
.type
,
1138 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
));
1142 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1143 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1145 if (crtc
>= dev
->num_crtcs
)
1148 ret
= drm_vblank_get(dev
, crtc
);
1150 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1153 seq
= drm_vblank_count(dev
, crtc
);
1155 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1156 case _DRM_VBLANK_RELATIVE
:
1157 vblwait
->request
.sequence
+= seq
;
1158 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1159 case _DRM_VBLANK_ABSOLUTE
:
1166 if (flags
& _DRM_VBLANK_EVENT
)
1167 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1169 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1170 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1171 vblwait
->request
.sequence
= seq
+ 1;
1174 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1175 vblwait
->request
.sequence
, crtc
);
1176 dev
->last_vblank_wait
[crtc
] = vblwait
->request
.sequence
;
1177 DRM_WAIT_ON(ret
, dev
->vbl_queue
[crtc
], 3 * DRM_HZ
,
1178 (((drm_vblank_count(dev
, crtc
) -
1179 vblwait
->request
.sequence
) <= (1 << 23)) ||
1180 !dev
->irq_enabled
));
1182 if (ret
!= -EINTR
) {
1185 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1186 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1187 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1189 DRM_DEBUG("returning %d to client\n",
1190 vblwait
->reply
.sequence
);
1192 DRM_DEBUG("vblank wait interrupted by signal\n");
1196 drm_vblank_put(dev
, crtc
);
1200 void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1202 struct drm_pending_vblank_event
*e
, *t
;
1204 unsigned long flags
;
1207 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1209 spin_lock_irqsave(&dev
->event_lock
, flags
);
1211 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1212 if (e
->pipe
!= crtc
)
1214 if ((seq
- e
->event
.sequence
) > (1<<23))
1217 DRM_DEBUG("vblank event on %d, current %d\n",
1218 e
->event
.sequence
, seq
);
1220 e
->event
.sequence
= seq
;
1221 e
->event
.tv_sec
= now
.tv_sec
;
1222 e
->event
.tv_usec
= now
.tv_usec
;
1223 drm_vblank_put(dev
, e
->pipe
);
1224 list_move_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1225 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1226 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1230 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1232 trace_drm_vblank_event(crtc
, seq
);
1236 * drm_handle_vblank - handle a vblank event
1238 * @crtc: where this event occurred
1240 * Drivers should call this routine in their vblank interrupt handlers to
1241 * update the vblank counter and send any signals that may be pending.
1243 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1247 struct timeval tvblank
;
1248 unsigned long irqflags
;
1250 if (!dev
->num_crtcs
)
1253 /* Need timestamp lock to prevent concurrent execution with
1254 * vblank enable/disable, as this would cause inconsistent
1255 * or corrupted timestamps and vblank counts.
1257 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1259 /* Vblank irq handling disabled. Nothing to do. */
1260 if (!dev
->vblank_enabled
[crtc
]) {
1261 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1265 /* Fetch corresponding timestamp for this vblank interval from
1266 * driver and store it in proper slot of timestamp ringbuffer.
1269 /* Get current timestamp and count. */
1270 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
1271 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1273 /* Compute time difference to timestamp of last vblank */
1274 diff_ns
= timeval_to_ns(&tvblank
) -
1275 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1277 /* Update vblank timestamp and count if at least
1278 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1279 * difference between last stored timestamp and current
1280 * timestamp. A smaller difference means basically
1281 * identical timestamps. Happens if this vblank has
1282 * been already processed and this is a redundant call,
1283 * e.g., due to spurious vblank interrupts. We need to
1284 * ignore those for accounting.
1286 if (abs(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1287 /* Store new timestamp in ringbuffer. */
1288 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1291 /* Increment cooked vblank count. This also atomically commits
1292 * the timestamp computed above.
1294 atomic_inc(&dev
->_vblank_count
[crtc
]);
1296 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1297 crtc
, (int) diff_ns
);
1300 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
1301 drm_handle_vblank_events(dev
, crtc
);
1303 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1306 EXPORT_SYMBOL(drm_handle_vblank
);