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 (drm_core_check_feature(dev
, DRIVER_USE_PLATFORM_DEVICE
))
80 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
83 if ((p
->busnum
>> 8) != drm_get_pci_domain(dev
) ||
84 (p
->busnum
& 0xff) != dev
->pdev
->bus
->number
||
85 p
->devnum
!= PCI_SLOT(dev
->pdev
->devfn
) || p
->funcnum
!= PCI_FUNC(dev
->pdev
->devfn
))
88 p
->irq
= dev
->pdev
->irq
;
90 DRM_DEBUG("%d:%d:%d => IRQ %d\n", p
->busnum
, p
->devnum
, p
->funcnum
,
97 * Clear vblank timestamp buffer for a crtc.
99 static void clear_vblank_timestamps(struct drm_device
*dev
, int crtc
)
101 memset(&dev
->_vblank_time
[crtc
* DRM_VBLANKTIME_RBSIZE
], 0,
102 DRM_VBLANKTIME_RBSIZE
* sizeof(struct timeval
));
106 * Disable vblank irq's on crtc, make sure that last vblank count
107 * of hardware and corresponding consistent software vblank counter
108 * are preserved, even if there are any spurious vblank irq's after
111 static void vblank_disable_and_save(struct drm_device
*dev
, int crtc
)
113 unsigned long irqflags
;
117 struct timeval tvblank
;
119 /* Prevent vblank irq processing while disabling vblank irqs,
120 * so no updates of timestamps or count can happen after we've
121 * disabled. Needed to prevent races in case of delayed irq's.
122 * Disable preemption, so vblank_time_lock is held as short as
123 * possible, even under a kernel with PREEMPT_RT patches.
126 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
128 dev
->driver
->disable_vblank(dev
, crtc
);
129 dev
->vblank_enabled
[crtc
] = 0;
131 /* No further vblank irq's will be processed after
132 * this point. Get current hardware vblank count and
133 * vblank timestamp, repeat until they are consistent.
135 * FIXME: There is still a race condition here and in
136 * drm_update_vblank_count() which can cause off-by-one
137 * reinitialization of software vblank counter. If gpu
138 * vblank counter doesn't increment exactly at the leading
139 * edge of a vblank interval, then we can lose 1 count if
140 * we happen to execute between start of vblank and the
141 * delayed gpu counter increment.
144 dev
->last_vblank
[crtc
] = dev
->driver
->get_vblank_counter(dev
, crtc
);
145 vblrc
= drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, 0);
146 } while (dev
->last_vblank
[crtc
] != dev
->driver
->get_vblank_counter(dev
, crtc
));
148 /* Compute time difference to stored timestamp of last vblank
149 * as updated by last invocation of drm_handle_vblank() in vblank irq.
151 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
152 diff_ns
= timeval_to_ns(&tvblank
) -
153 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
155 /* If there is at least 1 msec difference between the last stored
156 * timestamp and tvblank, then we are currently executing our
157 * disable inside a new vblank interval, the tvblank timestamp
158 * corresponds to this new vblank interval and the irq handler
159 * for this vblank didn't run yet and won't run due to our disable.
160 * Therefore we need to do the job of drm_handle_vblank() and
161 * increment the vblank counter by one to account for this vblank.
163 * Skip this step if there isn't any high precision timestamp
164 * available. In that case we can't account for this and just
167 if ((vblrc
> 0) && (abs64(diff_ns
) > 1000000)) {
168 atomic_inc(&dev
->_vblank_count
[crtc
]);
169 smp_mb__after_atomic_inc();
172 /* Invalidate all timestamps while vblank irq's are off. */
173 clear_vblank_timestamps(dev
, crtc
);
175 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
179 static void vblank_disable_fn(unsigned long arg
)
181 struct drm_device
*dev
= (struct drm_device
*)arg
;
182 unsigned long irqflags
;
185 if (!dev
->vblank_disable_allowed
)
188 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
189 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
190 if (atomic_read(&dev
->vblank_refcount
[i
]) == 0 &&
191 dev
->vblank_enabled
[i
]) {
192 DRM_DEBUG("disabling vblank on crtc %d\n", i
);
193 vblank_disable_and_save(dev
, i
);
195 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
199 void drm_vblank_cleanup(struct drm_device
*dev
)
201 /* Bail if the driver didn't call drm_vblank_init() */
202 if (dev
->num_crtcs
== 0)
205 del_timer(&dev
->vblank_disable_timer
);
207 vblank_disable_fn((unsigned long)dev
);
209 kfree(dev
->vbl_queue
);
210 kfree(dev
->_vblank_count
);
211 kfree(dev
->vblank_refcount
);
212 kfree(dev
->vblank_enabled
);
213 kfree(dev
->last_vblank
);
214 kfree(dev
->last_vblank_wait
);
215 kfree(dev
->vblank_inmodeset
);
216 kfree(dev
->_vblank_time
);
220 EXPORT_SYMBOL(drm_vblank_cleanup
);
222 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
224 int i
, ret
= -ENOMEM
;
226 setup_timer(&dev
->vblank_disable_timer
, vblank_disable_fn
,
228 spin_lock_init(&dev
->vbl_lock
);
229 spin_lock_init(&dev
->vblank_time_lock
);
231 dev
->num_crtcs
= num_crtcs
;
233 dev
->vbl_queue
= kmalloc(sizeof(wait_queue_head_t
) * num_crtcs
,
238 dev
->_vblank_count
= kmalloc(sizeof(atomic_t
) * num_crtcs
, GFP_KERNEL
);
239 if (!dev
->_vblank_count
)
242 dev
->vblank_refcount
= kmalloc(sizeof(atomic_t
) * num_crtcs
,
244 if (!dev
->vblank_refcount
)
247 dev
->vblank_enabled
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
248 if (!dev
->vblank_enabled
)
251 dev
->last_vblank
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
252 if (!dev
->last_vblank
)
255 dev
->last_vblank_wait
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
256 if (!dev
->last_vblank_wait
)
259 dev
->vblank_inmodeset
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
260 if (!dev
->vblank_inmodeset
)
263 dev
->_vblank_time
= kcalloc(num_crtcs
* DRM_VBLANKTIME_RBSIZE
,
264 sizeof(struct timeval
), GFP_KERNEL
);
265 if (!dev
->_vblank_time
)
268 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
270 /* Driver specific high-precision vblank timestamping supported? */
271 if (dev
->driver
->get_vblank_timestamp
)
272 DRM_INFO("Driver supports precise vblank timestamp query.\n");
274 DRM_INFO("No driver support for vblank timestamp query.\n");
276 /* Zero per-crtc vblank stuff */
277 for (i
= 0; i
< num_crtcs
; i
++) {
278 init_waitqueue_head(&dev
->vbl_queue
[i
]);
279 atomic_set(&dev
->_vblank_count
[i
], 0);
280 atomic_set(&dev
->vblank_refcount
[i
], 0);
283 dev
->vblank_disable_allowed
= 0;
287 drm_vblank_cleanup(dev
);
290 EXPORT_SYMBOL(drm_vblank_init
);
292 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
294 struct drm_device
*dev
= cookie
;
296 if (dev
->driver
->vgaarb_irq
) {
297 dev
->driver
->vgaarb_irq(dev
, state
);
301 if (!dev
->irq_enabled
)
305 dev
->driver
->irq_uninstall(dev
);
307 dev
->driver
->irq_preinstall(dev
);
308 dev
->driver
->irq_postinstall(dev
);
313 * Install IRQ handler.
315 * \param dev DRM device.
317 * Initializes the IRQ related data. Installs the handler, calling the driver
318 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
319 * before and after the installation.
321 int drm_irq_install(struct drm_device
*dev
)
324 unsigned long sh_flags
= 0;
327 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
330 if (drm_dev_to_irq(dev
) == 0)
333 mutex_lock(&dev
->struct_mutex
);
335 /* Driver must have been initialized */
336 if (!dev
->dev_private
) {
337 mutex_unlock(&dev
->struct_mutex
);
341 if (dev
->irq_enabled
) {
342 mutex_unlock(&dev
->struct_mutex
);
345 dev
->irq_enabled
= 1;
346 mutex_unlock(&dev
->struct_mutex
);
348 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
350 /* Before installing handler */
351 dev
->driver
->irq_preinstall(dev
);
353 /* Install handler */
354 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
355 sh_flags
= IRQF_SHARED
;
358 irqname
= dev
->devname
;
360 irqname
= dev
->driver
->name
;
362 ret
= request_irq(drm_dev_to_irq(dev
), dev
->driver
->irq_handler
,
363 sh_flags
, irqname
, dev
);
366 mutex_lock(&dev
->struct_mutex
);
367 dev
->irq_enabled
= 0;
368 mutex_unlock(&dev
->struct_mutex
);
372 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
373 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
375 /* After installing handler */
376 ret
= dev
->driver
->irq_postinstall(dev
);
378 mutex_lock(&dev
->struct_mutex
);
379 dev
->irq_enabled
= 0;
380 mutex_unlock(&dev
->struct_mutex
);
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 dev
->driver
->irq_uninstall(dev
);
428 free_irq(drm_dev_to_irq(dev
), dev
);
432 EXPORT_SYMBOL(drm_irq_uninstall
);
437 * \param inode device inode.
438 * \param file_priv DRM file private.
439 * \param cmd command.
440 * \param arg user argument, pointing to a drm_control structure.
441 * \return zero on success or a negative number on failure.
443 * Calls irq_install() or irq_uninstall() according to \p arg.
445 int drm_control(struct drm_device
*dev
, void *data
,
446 struct drm_file
*file_priv
)
448 struct drm_control
*ctl
= data
;
450 /* if we haven't irq we fallback for compatibility reasons -
451 * this used to be a separate function in drm_dma.h
456 case DRM_INST_HANDLER
:
457 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
459 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
461 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
462 ctl
->irq
!= drm_dev_to_irq(dev
))
464 return drm_irq_install(dev
);
465 case DRM_UNINST_HANDLER
:
466 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
468 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
470 return drm_irq_uninstall(dev
);
477 * drm_calc_timestamping_constants - Calculate and
478 * store various constants which are later needed by
479 * vblank and swap-completion timestamping, e.g, by
480 * drm_calc_vbltimestamp_from_scanoutpos().
481 * They are derived from crtc's true scanout timing,
482 * so they take things like panel scaling or other
483 * adjustments into account.
485 * @crtc drm_crtc whose timestamp constants should be updated.
488 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
490 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
493 /* Dot clock in Hz: */
494 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
496 /* Valid dotclock? */
498 /* Convert scanline length in pixels and video dot clock to
499 * line duration, frame duration and pixel duration in
502 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
503 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
504 1000000000), dotclock
);
505 framedur_ns
= (s64
) crtc
->hwmode
.crtc_vtotal
* linedur_ns
;
507 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
510 crtc
->pixeldur_ns
= pixeldur_ns
;
511 crtc
->linedur_ns
= linedur_ns
;
512 crtc
->framedur_ns
= framedur_ns
;
514 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
515 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
516 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
517 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
518 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
519 (int) linedur_ns
, (int) pixeldur_ns
);
521 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
524 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
525 * drivers. Implements calculation of exact vblank timestamps from
526 * given drm_display_mode timings and current video scanout position
527 * of a crtc. This can be called from within get_vblank_timestamp()
528 * implementation of a kms driver to implement the actual timestamping.
530 * Should return timestamps conforming to the OML_sync_control OpenML
531 * extension specification. The timestamp corresponds to the end of
532 * the vblank interval, aka start of scanout of topmost-leftmost display
533 * pixel in the following video frame.
535 * Requires support for optional dev->driver->get_scanout_position()
536 * in kms driver, plus a bit of setup code to provide a drm_display_mode
537 * that corresponds to the true scanout timing.
539 * The current implementation only handles standard video modes. It
540 * returns as no operation if a doublescan or interlaced video mode is
541 * active. Higher level code is expected to handle this.
544 * @crtc: Which crtc's vblank timestamp to retrieve.
545 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
546 * On return contains true maximum error of timestamp.
547 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
548 * @flags: Flags to pass to driver:
550 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
551 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
553 * Returns negative value on error, failure or if not supported in current
556 * -EINVAL - Invalid crtc.
557 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
558 * -ENOTSUPP - Function not supported in current display mode.
559 * -EIO - Failed, e.g., due to failed scanout position query.
561 * Returns or'ed positive status flags on success:
563 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
564 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
567 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
569 struct timeval
*vblank_time
,
571 struct drm_crtc
*refcrtc
)
573 struct timeval stime
, raw_time
;
574 struct drm_display_mode
*mode
;
575 int vbl_status
, vtotal
, vdisplay
;
577 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
580 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
581 DRM_ERROR("Invalid crtc %d\n", crtc
);
585 /* Scanout position query not supported? Should not happen. */
586 if (!dev
->driver
->get_scanout_position
) {
587 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
591 mode
= &refcrtc
->hwmode
;
592 vtotal
= mode
->crtc_vtotal
;
593 vdisplay
= mode
->crtc_vdisplay
;
595 /* Durations of frames, lines, pixels in nanoseconds. */
596 framedur_ns
= refcrtc
->framedur_ns
;
597 linedur_ns
= refcrtc
->linedur_ns
;
598 pixeldur_ns
= refcrtc
->pixeldur_ns
;
600 /* If mode timing undefined, just return as no-op:
601 * Happens during initial modesetting of a crtc.
603 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
604 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
608 /* Don't know yet how to handle interlaced or
609 * double scan modes. Just no-op for now.
611 if (mode
->flags
& (DRM_MODE_FLAG_INTERLACE
| DRM_MODE_FLAG_DBLSCAN
)) {
612 DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc
);
616 /* Get current scanout position with system timestamp.
617 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
618 * if single query takes longer than max_error nanoseconds.
620 * This guarantees a tight bound on maximum error if
621 * code gets preempted or delayed for some reason.
623 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
624 /* Disable preemption to make it very likely to
625 * succeed in the first iteration even on PREEMPT_RT kernel.
629 /* Get system timestamp before query. */
630 do_gettimeofday(&stime
);
632 /* Get vertical and horizontal scanout pos. vpos, hpos. */
633 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
635 /* Get system timestamp after query. */
636 do_gettimeofday(&raw_time
);
640 /* Return as no-op if scanout query unsupported or failed. */
641 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
642 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
647 duration_ns
= timeval_to_ns(&raw_time
) - timeval_to_ns(&stime
);
649 /* Accept result with < max_error nsecs timing uncertainty. */
650 if (duration_ns
<= (s64
) *max_error
)
654 /* Noisy system timing? */
655 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
656 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
657 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
660 /* Return upper bound of timestamp precision error. */
661 *max_error
= (int) duration_ns
;
663 /* Check if in vblank area:
664 * vpos is >=0 in video scanout area, but negative
665 * within vblank area, counting down the number of lines until
668 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
670 /* Convert scanout position into elapsed time at raw_time query
671 * since start of scanout at first display scanline. delta_ns
672 * can be negative if start of scanout hasn't happened yet.
674 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
676 /* Is vpos outside nominal vblank area, but less than
677 * 1/100 of a frame height away from start of vblank?
678 * If so, assume this isn't a massively delayed vblank
679 * interrupt, but a vblank interrupt that fired a few
680 * microseconds before true start of vblank. Compensate
681 * by adding a full frame duration to the final timestamp.
682 * Happens, e.g., on ATI R500, R600.
684 * We only do this if DRM_CALLED_FROM_VBLIRQ.
686 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
687 ((vdisplay
- vpos
) < vtotal
/ 100)) {
688 delta_ns
= delta_ns
- framedur_ns
;
690 /* Signal this correction as "applied". */
694 /* Subtract time delta from raw timestamp to get final
695 * vblank_time timestamp for end of vblank.
697 *vblank_time
= ns_to_timeval(timeval_to_ns(&raw_time
) - delta_ns
);
699 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %d.%d -> %d.%d [e %d us, %d rep]\n",
700 crtc
, (int) vbl_status
, hpos
, vpos
, raw_time
.tv_sec
,
701 raw_time
.tv_usec
, vblank_time
->tv_sec
, 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 unsigned long irqflags
;
949 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
950 vblank_disable_and_save(dev
, crtc
);
951 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
952 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
954 EXPORT_SYMBOL(drm_vblank_off
);
957 * drm_vblank_pre_modeset - account for vblanks across mode sets
959 * @crtc: CRTC in question
960 * @post: post or pre mode set?
962 * Account for vblank events across mode setting events, which will likely
963 * reset the hardware frame counter.
965 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
967 /* vblank is not initialized (IRQ not installed ?) */
971 * To avoid all the problems that might happen if interrupts
972 * were enabled/disabled around or between these calls, we just
973 * have the kernel take a reference on the CRTC (just once though
974 * to avoid corrupting the count if multiple, mismatch calls occur),
975 * so that interrupts remain enabled in the interim.
977 if (!dev
->vblank_inmodeset
[crtc
]) {
978 dev
->vblank_inmodeset
[crtc
] = 0x1;
979 if (drm_vblank_get(dev
, crtc
) == 0)
980 dev
->vblank_inmodeset
[crtc
] |= 0x2;
983 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
985 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
987 unsigned long irqflags
;
989 if (dev
->vblank_inmodeset
[crtc
]) {
990 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
991 dev
->vblank_disable_allowed
= 1;
992 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
994 if (dev
->vblank_inmodeset
[crtc
] & 0x2)
995 drm_vblank_put(dev
, crtc
);
997 dev
->vblank_inmodeset
[crtc
] = 0;
1000 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1003 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1004 * @DRM_IOCTL_ARGS: standard ioctl arguments
1006 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1007 * ioctls around modesetting so that any lost vblank events are accounted for.
1009 * Generally the counter will reset across mode sets. If interrupts are
1010 * enabled around this call, we don't have to do anything since the counter
1011 * will have already been incremented.
1013 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1014 struct drm_file
*file_priv
)
1016 struct drm_modeset_ctl
*modeset
= data
;
1019 /* If drm_vblank_init() hasn't been called yet, just no-op */
1020 if (!dev
->num_crtcs
)
1023 crtc
= modeset
->crtc
;
1024 if (crtc
>= dev
->num_crtcs
) {
1029 switch (modeset
->cmd
) {
1030 case _DRM_PRE_MODESET
:
1031 drm_vblank_pre_modeset(dev
, crtc
);
1033 case _DRM_POST_MODESET
:
1034 drm_vblank_post_modeset(dev
, crtc
);
1045 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1046 union drm_wait_vblank
*vblwait
,
1047 struct drm_file
*file_priv
)
1049 struct drm_pending_vblank_event
*e
;
1051 unsigned long flags
;
1055 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1062 e
->base
.pid
= current
->pid
;
1063 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1064 e
->event
.base
.length
= sizeof e
->event
;
1065 e
->event
.user_data
= vblwait
->request
.signal
;
1066 e
->base
.event
= &e
->event
.base
;
1067 e
->base
.file_priv
= file_priv
;
1068 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1070 spin_lock_irqsave(&dev
->event_lock
, flags
);
1072 if (file_priv
->event_space
< sizeof e
->event
) {
1077 file_priv
->event_space
-= sizeof e
->event
;
1078 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1080 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1081 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1082 vblwait
->request
.sequence
= seq
+ 1;
1083 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1086 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1087 vblwait
->request
.sequence
, seq
, pipe
);
1089 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1090 vblwait
->request
.sequence
);
1092 e
->event
.sequence
= vblwait
->request
.sequence
;
1093 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1094 e
->event
.sequence
= seq
;
1095 e
->event
.tv_sec
= now
.tv_sec
;
1096 e
->event
.tv_usec
= now
.tv_usec
;
1097 drm_vblank_put(dev
, pipe
);
1098 list_add_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1099 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1100 vblwait
->reply
.sequence
= seq
;
1101 trace_drm_vblank_event_delivered(current
->pid
, pipe
,
1102 vblwait
->request
.sequence
);
1104 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1105 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1108 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1113 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1116 drm_vblank_put(dev
, pipe
);
1123 * \param inode device inode.
1124 * \param file_priv DRM file private.
1125 * \param cmd command.
1126 * \param data user argument, pointing to a drm_wait_vblank structure.
1127 * \return zero on success or a negative number on failure.
1129 * This function enables the vblank interrupt on the pipe requested, then
1130 * sleeps waiting for the requested sequence number to occur, and drops
1131 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1132 * after a timeout with no further vblank waits scheduled).
1134 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1135 struct drm_file
*file_priv
)
1137 union drm_wait_vblank
*vblwait
= data
;
1139 unsigned int flags
, seq
, crtc
;
1141 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1144 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1147 if (vblwait
->request
.type
&
1148 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
)) {
1149 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1150 vblwait
->request
.type
,
1151 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
));
1155 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1156 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1158 if (crtc
>= dev
->num_crtcs
)
1161 ret
= drm_vblank_get(dev
, crtc
);
1163 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1166 seq
= drm_vblank_count(dev
, crtc
);
1168 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1169 case _DRM_VBLANK_RELATIVE
:
1170 vblwait
->request
.sequence
+= seq
;
1171 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1172 case _DRM_VBLANK_ABSOLUTE
:
1179 if (flags
& _DRM_VBLANK_EVENT
)
1180 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1182 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1183 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1184 vblwait
->request
.sequence
= seq
+ 1;
1187 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1188 vblwait
->request
.sequence
, crtc
);
1189 dev
->last_vblank_wait
[crtc
] = vblwait
->request
.sequence
;
1190 DRM_WAIT_ON(ret
, dev
->vbl_queue
[crtc
], 3 * DRM_HZ
,
1191 (((drm_vblank_count(dev
, crtc
) -
1192 vblwait
->request
.sequence
) <= (1 << 23)) ||
1193 !dev
->irq_enabled
));
1195 if (ret
!= -EINTR
) {
1198 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1199 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1200 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1202 DRM_DEBUG("returning %d to client\n",
1203 vblwait
->reply
.sequence
);
1205 DRM_DEBUG("vblank wait interrupted by signal\n");
1209 drm_vblank_put(dev
, crtc
);
1213 void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1215 struct drm_pending_vblank_event
*e
, *t
;
1217 unsigned long flags
;
1220 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1222 spin_lock_irqsave(&dev
->event_lock
, flags
);
1224 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1225 if (e
->pipe
!= crtc
)
1227 if ((seq
- e
->event
.sequence
) > (1<<23))
1230 DRM_DEBUG("vblank event on %d, current %d\n",
1231 e
->event
.sequence
, seq
);
1233 e
->event
.sequence
= seq
;
1234 e
->event
.tv_sec
= now
.tv_sec
;
1235 e
->event
.tv_usec
= now
.tv_usec
;
1236 drm_vblank_put(dev
, e
->pipe
);
1237 list_move_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1238 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1239 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1243 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1245 trace_drm_vblank_event(crtc
, seq
);
1249 * drm_handle_vblank - handle a vblank event
1251 * @crtc: where this event occurred
1253 * Drivers should call this routine in their vblank interrupt handlers to
1254 * update the vblank counter and send any signals that may be pending.
1256 bool drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1260 struct timeval tvblank
;
1261 unsigned long irqflags
;
1263 if (!dev
->num_crtcs
)
1266 /* Need timestamp lock to prevent concurrent execution with
1267 * vblank enable/disable, as this would cause inconsistent
1268 * or corrupted timestamps and vblank counts.
1270 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1272 /* Vblank irq handling disabled. Nothing to do. */
1273 if (!dev
->vblank_enabled
[crtc
]) {
1274 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1278 /* Fetch corresponding timestamp for this vblank interval from
1279 * driver and store it in proper slot of timestamp ringbuffer.
1282 /* Get current timestamp and count. */
1283 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
1284 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1286 /* Compute time difference to timestamp of last vblank */
1287 diff_ns
= timeval_to_ns(&tvblank
) -
1288 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1290 /* Update vblank timestamp and count if at least
1291 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1292 * difference between last stored timestamp and current
1293 * timestamp. A smaller difference means basically
1294 * identical timestamps. Happens if this vblank has
1295 * been already processed and this is a redundant call,
1296 * e.g., due to spurious vblank interrupts. We need to
1297 * ignore those for accounting.
1299 if (abs64(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1300 /* Store new timestamp in ringbuffer. */
1301 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1303 /* Increment cooked vblank count. This also atomically commits
1304 * the timestamp computed above.
1306 smp_mb__before_atomic_inc();
1307 atomic_inc(&dev
->_vblank_count
[crtc
]);
1308 smp_mb__after_atomic_inc();
1310 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1311 crtc
, (int) diff_ns
);
1314 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
1315 drm_handle_vblank_events(dev
, crtc
);
1317 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1320 EXPORT_SYMBOL(drm_handle_vblank
);