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) && (abs(diff_ns
) > 1000000))
168 atomic_inc(&dev
->_vblank_count
[crtc
]);
170 /* Invalidate all timestamps while vblank irq's are off. */
171 clear_vblank_timestamps(dev
, crtc
);
173 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
177 static void vblank_disable_fn(unsigned long arg
)
179 struct drm_device
*dev
= (struct drm_device
*)arg
;
180 unsigned long irqflags
;
183 if (!dev
->vblank_disable_allowed
)
186 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
187 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
188 if (atomic_read(&dev
->vblank_refcount
[i
]) == 0 &&
189 dev
->vblank_enabled
[i
]) {
190 DRM_DEBUG("disabling vblank on crtc %d\n", i
);
191 vblank_disable_and_save(dev
, i
);
193 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
197 void drm_vblank_cleanup(struct drm_device
*dev
)
199 /* Bail if the driver didn't call drm_vblank_init() */
200 if (dev
->num_crtcs
== 0)
203 del_timer(&dev
->vblank_disable_timer
);
205 vblank_disable_fn((unsigned long)dev
);
207 kfree(dev
->vbl_queue
);
208 kfree(dev
->_vblank_count
);
209 kfree(dev
->vblank_refcount
);
210 kfree(dev
->vblank_enabled
);
211 kfree(dev
->last_vblank
);
212 kfree(dev
->last_vblank_wait
);
213 kfree(dev
->vblank_inmodeset
);
214 kfree(dev
->_vblank_time
);
218 EXPORT_SYMBOL(drm_vblank_cleanup
);
220 int drm_vblank_init(struct drm_device
*dev
, int num_crtcs
)
222 int i
, ret
= -ENOMEM
;
224 setup_timer(&dev
->vblank_disable_timer
, vblank_disable_fn
,
226 spin_lock_init(&dev
->vbl_lock
);
227 spin_lock_init(&dev
->vblank_time_lock
);
229 dev
->num_crtcs
= num_crtcs
;
231 dev
->vbl_queue
= kmalloc(sizeof(wait_queue_head_t
) * num_crtcs
,
236 dev
->_vblank_count
= kmalloc(sizeof(atomic_t
) * num_crtcs
, GFP_KERNEL
);
237 if (!dev
->_vblank_count
)
240 dev
->vblank_refcount
= kmalloc(sizeof(atomic_t
) * num_crtcs
,
242 if (!dev
->vblank_refcount
)
245 dev
->vblank_enabled
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
246 if (!dev
->vblank_enabled
)
249 dev
->last_vblank
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
250 if (!dev
->last_vblank
)
253 dev
->last_vblank_wait
= kcalloc(num_crtcs
, sizeof(u32
), GFP_KERNEL
);
254 if (!dev
->last_vblank_wait
)
257 dev
->vblank_inmodeset
= kcalloc(num_crtcs
, sizeof(int), GFP_KERNEL
);
258 if (!dev
->vblank_inmodeset
)
261 dev
->_vblank_time
= kcalloc(num_crtcs
* DRM_VBLANKTIME_RBSIZE
,
262 sizeof(struct timeval
), GFP_KERNEL
);
263 if (!dev
->_vblank_time
)
266 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n");
268 /* Driver specific high-precision vblank timestamping supported? */
269 if (dev
->driver
->get_vblank_timestamp
)
270 DRM_INFO("Driver supports precise vblank timestamp query.\n");
272 DRM_INFO("No driver support for vblank timestamp query.\n");
274 /* Zero per-crtc vblank stuff */
275 for (i
= 0; i
< num_crtcs
; i
++) {
276 init_waitqueue_head(&dev
->vbl_queue
[i
]);
277 atomic_set(&dev
->_vblank_count
[i
], 0);
278 atomic_set(&dev
->vblank_refcount
[i
], 0);
281 dev
->vblank_disable_allowed
= 0;
285 drm_vblank_cleanup(dev
);
288 EXPORT_SYMBOL(drm_vblank_init
);
290 static void drm_irq_vgaarb_nokms(void *cookie
, bool state
)
292 struct drm_device
*dev
= cookie
;
294 if (dev
->driver
->vgaarb_irq
) {
295 dev
->driver
->vgaarb_irq(dev
, state
);
299 if (!dev
->irq_enabled
)
303 dev
->driver
->irq_uninstall(dev
);
305 dev
->driver
->irq_preinstall(dev
);
306 dev
->driver
->irq_postinstall(dev
);
311 * Install IRQ handler.
313 * \param dev DRM device.
315 * Initializes the IRQ related data. Installs the handler, calling the driver
316 * \c drm_driver_irq_preinstall() and \c drm_driver_irq_postinstall() functions
317 * before and after the installation.
319 int drm_irq_install(struct drm_device
*dev
)
322 unsigned long sh_flags
= 0;
325 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
328 if (drm_dev_to_irq(dev
) == 0)
331 mutex_lock(&dev
->struct_mutex
);
333 /* Driver must have been initialized */
334 if (!dev
->dev_private
) {
335 mutex_unlock(&dev
->struct_mutex
);
339 if (dev
->irq_enabled
) {
340 mutex_unlock(&dev
->struct_mutex
);
343 dev
->irq_enabled
= 1;
344 mutex_unlock(&dev
->struct_mutex
);
346 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
348 /* Before installing handler */
349 dev
->driver
->irq_preinstall(dev
);
351 /* Install handler */
352 if (drm_core_check_feature(dev
, DRIVER_IRQ_SHARED
))
353 sh_flags
= IRQF_SHARED
;
356 irqname
= dev
->devname
;
358 irqname
= dev
->driver
->name
;
360 ret
= request_irq(drm_dev_to_irq(dev
), dev
->driver
->irq_handler
,
361 sh_flags
, irqname
, dev
);
364 mutex_lock(&dev
->struct_mutex
);
365 dev
->irq_enabled
= 0;
366 mutex_unlock(&dev
->struct_mutex
);
370 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
371 vga_client_register(dev
->pdev
, (void *)dev
, drm_irq_vgaarb_nokms
, NULL
);
373 /* After installing handler */
374 ret
= dev
->driver
->irq_postinstall(dev
);
376 mutex_lock(&dev
->struct_mutex
);
377 dev
->irq_enabled
= 0;
378 mutex_unlock(&dev
->struct_mutex
);
383 EXPORT_SYMBOL(drm_irq_install
);
386 * Uninstall the IRQ handler.
388 * \param dev DRM device.
390 * Calls the driver's \c drm_driver_irq_uninstall() function, and stops the irq.
392 int drm_irq_uninstall(struct drm_device
*dev
)
394 unsigned long irqflags
;
397 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
400 mutex_lock(&dev
->struct_mutex
);
401 irq_enabled
= dev
->irq_enabled
;
402 dev
->irq_enabled
= 0;
403 mutex_unlock(&dev
->struct_mutex
);
406 * Wake up any waiters so they don't hang.
408 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
409 for (i
= 0; i
< dev
->num_crtcs
; i
++) {
410 DRM_WAKEUP(&dev
->vbl_queue
[i
]);
411 dev
->vblank_enabled
[i
] = 0;
412 dev
->last_vblank
[i
] = dev
->driver
->get_vblank_counter(dev
, i
);
414 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
419 DRM_DEBUG("irq=%d\n", drm_dev_to_irq(dev
));
421 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
422 vga_client_register(dev
->pdev
, NULL
, NULL
, NULL
);
424 dev
->driver
->irq_uninstall(dev
);
426 free_irq(drm_dev_to_irq(dev
), dev
);
430 EXPORT_SYMBOL(drm_irq_uninstall
);
435 * \param inode device inode.
436 * \param file_priv DRM file private.
437 * \param cmd command.
438 * \param arg user argument, pointing to a drm_control structure.
439 * \return zero on success or a negative number on failure.
441 * Calls irq_install() or irq_uninstall() according to \p arg.
443 int drm_control(struct drm_device
*dev
, void *data
,
444 struct drm_file
*file_priv
)
446 struct drm_control
*ctl
= data
;
448 /* if we haven't irq we fallback for compatibility reasons -
449 * this used to be a separate function in drm_dma.h
454 case DRM_INST_HANDLER
:
455 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
457 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
459 if (dev
->if_version
< DRM_IF_VERSION(1, 2) &&
460 ctl
->irq
!= drm_dev_to_irq(dev
))
462 return drm_irq_install(dev
);
463 case DRM_UNINST_HANDLER
:
464 if (!drm_core_check_feature(dev
, DRIVER_HAVE_IRQ
))
466 if (drm_core_check_feature(dev
, DRIVER_MODESET
))
468 return drm_irq_uninstall(dev
);
475 * drm_calc_timestamping_constants - Calculate and
476 * store various constants which are later needed by
477 * vblank and swap-completion timestamping, e.g, by
478 * drm_calc_vbltimestamp_from_scanoutpos().
479 * They are derived from crtc's true scanout timing,
480 * so they take things like panel scaling or other
481 * adjustments into account.
483 * @crtc drm_crtc whose timestamp constants should be updated.
486 void drm_calc_timestamping_constants(struct drm_crtc
*crtc
)
488 s64 linedur_ns
= 0, pixeldur_ns
= 0, framedur_ns
= 0;
491 /* Dot clock in Hz: */
492 dotclock
= (u64
) crtc
->hwmode
.clock
* 1000;
494 /* Valid dotclock? */
496 /* Convert scanline length in pixels and video dot clock to
497 * line duration, frame duration and pixel duration in
500 pixeldur_ns
= (s64
) div64_u64(1000000000, dotclock
);
501 linedur_ns
= (s64
) div64_u64(((u64
) crtc
->hwmode
.crtc_htotal
*
502 1000000000), dotclock
);
503 framedur_ns
= (s64
) crtc
->hwmode
.crtc_vtotal
* linedur_ns
;
505 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n",
508 crtc
->pixeldur_ns
= pixeldur_ns
;
509 crtc
->linedur_ns
= linedur_ns
;
510 crtc
->framedur_ns
= framedur_ns
;
512 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n",
513 crtc
->base
.id
, crtc
->hwmode
.crtc_htotal
,
514 crtc
->hwmode
.crtc_vtotal
, crtc
->hwmode
.crtc_vdisplay
);
515 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n",
516 crtc
->base
.id
, (int) dotclock
/1000, (int) framedur_ns
,
517 (int) linedur_ns
, (int) pixeldur_ns
);
519 EXPORT_SYMBOL(drm_calc_timestamping_constants
);
522 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms
523 * drivers. Implements calculation of exact vblank timestamps from
524 * given drm_display_mode timings and current video scanout position
525 * of a crtc. This can be called from within get_vblank_timestamp()
526 * implementation of a kms driver to implement the actual timestamping.
528 * Should return timestamps conforming to the OML_sync_control OpenML
529 * extension specification. The timestamp corresponds to the end of
530 * the vblank interval, aka start of scanout of topmost-leftmost display
531 * pixel in the following video frame.
533 * Requires support for optional dev->driver->get_scanout_position()
534 * in kms driver, plus a bit of setup code to provide a drm_display_mode
535 * that corresponds to the true scanout timing.
537 * The current implementation only handles standard video modes. It
538 * returns as no operation if a doublescan or interlaced video mode is
539 * active. Higher level code is expected to handle this.
542 * @crtc: Which crtc's vblank timestamp to retrieve.
543 * @max_error: Desired maximum allowable error in timestamps (nanosecs).
544 * On return contains true maximum error of timestamp.
545 * @vblank_time: Pointer to struct timeval which should receive the timestamp.
546 * @flags: Flags to pass to driver:
548 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
549 * @refcrtc: drm_crtc* of crtc which defines scanout timing.
551 * Returns negative value on error, failure or if not supported in current
554 * -EINVAL - Invalid crtc.
555 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset.
556 * -ENOTSUPP - Function not supported in current display mode.
557 * -EIO - Failed, e.g., due to failed scanout position query.
559 * Returns or'ed positive status flags on success:
561 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping.
562 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval.
565 int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device
*dev
, int crtc
,
567 struct timeval
*vblank_time
,
569 struct drm_crtc
*refcrtc
)
571 struct timeval stime
, raw_time
;
572 struct drm_display_mode
*mode
;
573 int vbl_status
, vtotal
, vdisplay
;
575 s64 framedur_ns
, linedur_ns
, pixeldur_ns
, delta_ns
, duration_ns
;
578 if (crtc
< 0 || crtc
>= dev
->num_crtcs
) {
579 DRM_ERROR("Invalid crtc %d\n", crtc
);
583 /* Scanout position query not supported? Should not happen. */
584 if (!dev
->driver
->get_scanout_position
) {
585 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n");
589 mode
= &refcrtc
->hwmode
;
590 vtotal
= mode
->crtc_vtotal
;
591 vdisplay
= mode
->crtc_vdisplay
;
593 /* Durations of frames, lines, pixels in nanoseconds. */
594 framedur_ns
= refcrtc
->framedur_ns
;
595 linedur_ns
= refcrtc
->linedur_ns
;
596 pixeldur_ns
= refcrtc
->pixeldur_ns
;
598 /* If mode timing undefined, just return as no-op:
599 * Happens during initial modesetting of a crtc.
601 if (vtotal
<= 0 || vdisplay
<= 0 || framedur_ns
== 0) {
602 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc
);
606 /* Don't know yet how to handle interlaced or
607 * double scan modes. Just no-op for now.
609 if (mode
->flags
& (DRM_MODE_FLAG_INTERLACE
| DRM_MODE_FLAG_DBLSCAN
)) {
610 DRM_DEBUG("crtc %d: Noop due to unsupported mode.\n", crtc
);
614 /* Get current scanout position with system timestamp.
615 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times
616 * if single query takes longer than max_error nanoseconds.
618 * This guarantees a tight bound on maximum error if
619 * code gets preempted or delayed for some reason.
621 for (i
= 0; i
< DRM_TIMESTAMP_MAXRETRIES
; i
++) {
622 /* Disable preemption to make it very likely to
623 * succeed in the first iteration even on PREEMPT_RT kernel.
627 /* Get system timestamp before query. */
628 do_gettimeofday(&stime
);
630 /* Get vertical and horizontal scanout pos. vpos, hpos. */
631 vbl_status
= dev
->driver
->get_scanout_position(dev
, crtc
, &vpos
, &hpos
);
633 /* Get system timestamp after query. */
634 do_gettimeofday(&raw_time
);
638 /* Return as no-op if scanout query unsupported or failed. */
639 if (!(vbl_status
& DRM_SCANOUTPOS_VALID
)) {
640 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n",
645 duration_ns
= timeval_to_ns(&raw_time
) - timeval_to_ns(&stime
);
647 /* Accept result with < max_error nsecs timing uncertainty. */
648 if (duration_ns
<= (s64
) *max_error
)
652 /* Noisy system timing? */
653 if (i
== DRM_TIMESTAMP_MAXRETRIES
) {
654 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n",
655 crtc
, (int) duration_ns
/1000, *max_error
/1000, i
);
658 /* Return upper bound of timestamp precision error. */
659 *max_error
= (int) duration_ns
;
661 /* Check if in vblank area:
662 * vpos is >=0 in video scanout area, but negative
663 * within vblank area, counting down the number of lines until
666 invbl
= vbl_status
& DRM_SCANOUTPOS_INVBL
;
668 /* Convert scanout position into elapsed time at raw_time query
669 * since start of scanout at first display scanline. delta_ns
670 * can be negative if start of scanout hasn't happened yet.
672 delta_ns
= (s64
) vpos
* linedur_ns
+ (s64
) hpos
* pixeldur_ns
;
674 /* Is vpos outside nominal vblank area, but less than
675 * 1/100 of a frame height away from start of vblank?
676 * If so, assume this isn't a massively delayed vblank
677 * interrupt, but a vblank interrupt that fired a few
678 * microseconds before true start of vblank. Compensate
679 * by adding a full frame duration to the final timestamp.
680 * Happens, e.g., on ATI R500, R600.
682 * We only do this if DRM_CALLED_FROM_VBLIRQ.
684 if ((flags
& DRM_CALLED_FROM_VBLIRQ
) && !invbl
&&
685 ((vdisplay
- vpos
) < vtotal
/ 100)) {
686 delta_ns
= delta_ns
- framedur_ns
;
688 /* Signal this correction as "applied". */
692 /* Subtract time delta from raw timestamp to get final
693 * vblank_time timestamp for end of vblank.
695 *vblank_time
= ns_to_timeval(timeval_to_ns(&raw_time
) - delta_ns
);
697 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %d.%d -> %d.%d [e %d us, %d rep]\n",
698 crtc
, (int) vbl_status
, hpos
, vpos
, raw_time
.tv_sec
,
699 raw_time
.tv_usec
, vblank_time
->tv_sec
, vblank_time
->tv_usec
,
700 (int) duration_ns
/1000, i
);
702 vbl_status
= DRM_VBLANKTIME_SCANOUTPOS_METHOD
;
704 vbl_status
|= DRM_VBLANKTIME_INVBL
;
708 EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos
);
711 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent
715 * @crtc: which crtc's vblank timestamp to retrieve
716 * @tvblank: Pointer to target struct timeval which should receive the timestamp
717 * @flags: Flags to pass to driver:
719 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler.
721 * Fetches the system timestamp corresponding to the time of the most recent
722 * vblank interval on specified crtc. May call into kms-driver to
723 * compute the timestamp with a high-precision GPU specific method.
725 * Returns zero if timestamp originates from uncorrected do_gettimeofday()
726 * call, i.e., it isn't very precisely locked to the true vblank.
728 * Returns non-zero if timestamp is considered to be very precise.
730 u32
drm_get_last_vbltimestamp(struct drm_device
*dev
, int crtc
,
731 struct timeval
*tvblank
, unsigned flags
)
735 /* Define requested maximum error on timestamps (nanoseconds). */
736 int max_error
= (int) drm_timestamp_precision
* 1000;
738 /* Query driver if possible and precision timestamping enabled. */
739 if (dev
->driver
->get_vblank_timestamp
&& (max_error
> 0)) {
740 ret
= dev
->driver
->get_vblank_timestamp(dev
, crtc
, &max_error
,
746 /* GPU high precision timestamp query unsupported or failed.
747 * Return gettimeofday timestamp as best estimate.
749 do_gettimeofday(tvblank
);
753 EXPORT_SYMBOL(drm_get_last_vbltimestamp
);
756 * drm_vblank_count - retrieve "cooked" vblank counter value
758 * @crtc: which counter to retrieve
760 * Fetches the "cooked" vblank count value that represents the number of
761 * vblank events since the system was booted, including lost events due to
762 * modesetting activity.
764 u32
drm_vblank_count(struct drm_device
*dev
, int crtc
)
766 return atomic_read(&dev
->_vblank_count
[crtc
]);
768 EXPORT_SYMBOL(drm_vblank_count
);
771 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value
772 * and the system timestamp corresponding to that vblank counter value.
775 * @crtc: which counter to retrieve
776 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp.
778 * Fetches the "cooked" vblank count value that represents the number of
779 * vblank events since the system was booted, including lost events due to
780 * modesetting activity. Returns corresponding system timestamp of the time
781 * of the vblank interval that corresponds to the current value vblank counter
784 u32
drm_vblank_count_and_time(struct drm_device
*dev
, int crtc
,
785 struct timeval
*vblanktime
)
789 /* Read timestamp from slot of _vblank_time ringbuffer
790 * that corresponds to current vblank count. Retry if
791 * count has incremented during readout. This works like
795 cur_vblank
= atomic_read(&dev
->_vblank_count
[crtc
]);
796 *vblanktime
= vblanktimestamp(dev
, crtc
, cur_vblank
);
798 } while (cur_vblank
!= atomic_read(&dev
->_vblank_count
[crtc
]));
802 EXPORT_SYMBOL(drm_vblank_count_and_time
);
805 * drm_update_vblank_count - update the master vblank counter
807 * @crtc: counter to update
809 * Call back into the driver to update the appropriate vblank counter
810 * (specified by @crtc). Deal with wraparound, if it occurred, and
811 * update the last read value so we can deal with wraparound on the next
814 * Only necessary when going from off->on, to account for frames we
815 * didn't get an interrupt for.
817 * Note: caller must hold dev->vbl_lock since this reads & writes
818 * device vblank fields.
820 static void drm_update_vblank_count(struct drm_device
*dev
, int crtc
)
822 u32 cur_vblank
, diff
, tslot
, rc
;
823 struct timeval t_vblank
;
826 * Interrupts were disabled prior to this call, so deal with counter
828 * NOTE! It's possible we lost a full dev->max_vblank_count events
829 * here if the register is small or we had vblank interrupts off for
832 * We repeat the hardware vblank counter & timestamp query until
833 * we get consistent results. This to prevent races between gpu
834 * updating its hardware counter while we are retrieving the
835 * corresponding vblank timestamp.
838 cur_vblank
= dev
->driver
->get_vblank_counter(dev
, crtc
);
839 rc
= drm_get_last_vbltimestamp(dev
, crtc
, &t_vblank
, 0);
840 } while (cur_vblank
!= dev
->driver
->get_vblank_counter(dev
, crtc
));
842 /* Deal with counter wrap */
843 diff
= cur_vblank
- dev
->last_vblank
[crtc
];
844 if (cur_vblank
< dev
->last_vblank
[crtc
]) {
845 diff
+= dev
->max_vblank_count
;
847 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n",
848 crtc
, dev
->last_vblank
[crtc
], cur_vblank
, diff
);
851 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
854 /* Reinitialize corresponding vblank timestamp if high-precision query
855 * available. Skip this step if query unsupported or failed. Will
856 * reinitialize delayed at next vblank interrupt in that case.
859 tslot
= atomic_read(&dev
->_vblank_count
[crtc
]) + diff
;
860 vblanktimestamp(dev
, crtc
, tslot
) = t_vblank
;
864 atomic_add(diff
, &dev
->_vblank_count
[crtc
]);
868 * drm_vblank_get - get a reference count on vblank events
870 * @crtc: which CRTC to own
872 * Acquire a reference count on vblank events to avoid having them disabled
876 * Zero on success, nonzero on failure.
878 int drm_vblank_get(struct drm_device
*dev
, int crtc
)
880 unsigned long irqflags
, irqflags2
;
883 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
884 /* Going from 0->1 means we have to enable interrupts again */
885 if (atomic_add_return(1, &dev
->vblank_refcount
[crtc
]) == 1) {
886 /* Disable preemption while holding vblank_time_lock. Do
887 * it explicitely to guard against PREEMPT_RT kernel.
890 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags2
);
891 if (!dev
->vblank_enabled
[crtc
]) {
892 /* Enable vblank irqs under vblank_time_lock protection.
893 * All vblank count & timestamp updates are held off
894 * until we are done reinitializing master counter and
895 * timestamps. Filtercode in drm_handle_vblank() will
896 * prevent double-accounting of same vblank interval.
898 ret
= dev
->driver
->enable_vblank(dev
, crtc
);
899 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n",
902 atomic_dec(&dev
->vblank_refcount
[crtc
]);
904 dev
->vblank_enabled
[crtc
] = 1;
905 drm_update_vblank_count(dev
, crtc
);
908 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags2
);
911 if (!dev
->vblank_enabled
[crtc
]) {
912 atomic_dec(&dev
->vblank_refcount
[crtc
]);
916 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
920 EXPORT_SYMBOL(drm_vblank_get
);
923 * drm_vblank_put - give up ownership of vblank events
925 * @crtc: which counter to give up
927 * Release ownership of a given vblank counter, turning off interrupts
928 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds.
930 void drm_vblank_put(struct drm_device
*dev
, int crtc
)
932 BUG_ON(atomic_read(&dev
->vblank_refcount
[crtc
]) == 0);
934 /* Last user schedules interrupt disable */
935 if (atomic_dec_and_test(&dev
->vblank_refcount
[crtc
]) &&
936 (drm_vblank_offdelay
> 0))
937 mod_timer(&dev
->vblank_disable_timer
,
938 jiffies
+ ((drm_vblank_offdelay
* DRM_HZ
)/1000));
940 EXPORT_SYMBOL(drm_vblank_put
);
942 void drm_vblank_off(struct drm_device
*dev
, int crtc
)
944 unsigned long irqflags
;
946 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
947 vblank_disable_and_save(dev
, crtc
);
948 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
949 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
951 EXPORT_SYMBOL(drm_vblank_off
);
954 * drm_vblank_pre_modeset - account for vblanks across mode sets
956 * @crtc: CRTC in question
957 * @post: post or pre mode set?
959 * Account for vblank events across mode setting events, which will likely
960 * reset the hardware frame counter.
962 void drm_vblank_pre_modeset(struct drm_device
*dev
, int crtc
)
964 /* vblank is not initialized (IRQ not installed ?) */
968 * To avoid all the problems that might happen if interrupts
969 * were enabled/disabled around or between these calls, we just
970 * have the kernel take a reference on the CRTC (just once though
971 * to avoid corrupting the count if multiple, mismatch calls occur),
972 * so that interrupts remain enabled in the interim.
974 if (!dev
->vblank_inmodeset
[crtc
]) {
975 dev
->vblank_inmodeset
[crtc
] = 0x1;
976 if (drm_vblank_get(dev
, crtc
) == 0)
977 dev
->vblank_inmodeset
[crtc
] |= 0x2;
980 EXPORT_SYMBOL(drm_vblank_pre_modeset
);
982 void drm_vblank_post_modeset(struct drm_device
*dev
, int crtc
)
984 unsigned long irqflags
;
986 if (dev
->vblank_inmodeset
[crtc
]) {
987 spin_lock_irqsave(&dev
->vbl_lock
, irqflags
);
988 dev
->vblank_disable_allowed
= 1;
989 spin_unlock_irqrestore(&dev
->vbl_lock
, irqflags
);
991 if (dev
->vblank_inmodeset
[crtc
] & 0x2)
992 drm_vblank_put(dev
, crtc
);
994 dev
->vblank_inmodeset
[crtc
] = 0;
997 EXPORT_SYMBOL(drm_vblank_post_modeset
);
1000 * drm_modeset_ctl - handle vblank event counter changes across mode switch
1001 * @DRM_IOCTL_ARGS: standard ioctl arguments
1003 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET
1004 * ioctls around modesetting so that any lost vblank events are accounted for.
1006 * Generally the counter will reset across mode sets. If interrupts are
1007 * enabled around this call, we don't have to do anything since the counter
1008 * will have already been incremented.
1010 int drm_modeset_ctl(struct drm_device
*dev
, void *data
,
1011 struct drm_file
*file_priv
)
1013 struct drm_modeset_ctl
*modeset
= data
;
1016 /* If drm_vblank_init() hasn't been called yet, just no-op */
1017 if (!dev
->num_crtcs
)
1020 crtc
= modeset
->crtc
;
1021 if (crtc
>= dev
->num_crtcs
) {
1026 switch (modeset
->cmd
) {
1027 case _DRM_PRE_MODESET
:
1028 drm_vblank_pre_modeset(dev
, crtc
);
1030 case _DRM_POST_MODESET
:
1031 drm_vblank_post_modeset(dev
, crtc
);
1042 static int drm_queue_vblank_event(struct drm_device
*dev
, int pipe
,
1043 union drm_wait_vblank
*vblwait
,
1044 struct drm_file
*file_priv
)
1046 struct drm_pending_vblank_event
*e
;
1048 unsigned long flags
;
1052 e
= kzalloc(sizeof *e
, GFP_KERNEL
);
1059 e
->base
.pid
= current
->pid
;
1060 e
->event
.base
.type
= DRM_EVENT_VBLANK
;
1061 e
->event
.base
.length
= sizeof e
->event
;
1062 e
->event
.user_data
= vblwait
->request
.signal
;
1063 e
->base
.event
= &e
->event
.base
;
1064 e
->base
.file_priv
= file_priv
;
1065 e
->base
.destroy
= (void (*) (struct drm_pending_event
*)) kfree
;
1067 spin_lock_irqsave(&dev
->event_lock
, flags
);
1069 if (file_priv
->event_space
< sizeof e
->event
) {
1074 file_priv
->event_space
-= sizeof e
->event
;
1075 seq
= drm_vblank_count_and_time(dev
, pipe
, &now
);
1077 if ((vblwait
->request
.type
& _DRM_VBLANK_NEXTONMISS
) &&
1078 (seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1079 vblwait
->request
.sequence
= seq
+ 1;
1080 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1083 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n",
1084 vblwait
->request
.sequence
, seq
, pipe
);
1086 trace_drm_vblank_event_queued(current
->pid
, pipe
,
1087 vblwait
->request
.sequence
);
1089 e
->event
.sequence
= vblwait
->request
.sequence
;
1090 if ((seq
- vblwait
->request
.sequence
) <= (1 << 23)) {
1091 e
->event
.sequence
= seq
;
1092 e
->event
.tv_sec
= now
.tv_sec
;
1093 e
->event
.tv_usec
= now
.tv_usec
;
1094 drm_vblank_put(dev
, pipe
);
1095 list_add_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1096 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1097 vblwait
->reply
.sequence
= seq
;
1098 trace_drm_vblank_event_delivered(current
->pid
, pipe
,
1099 vblwait
->request
.sequence
);
1101 list_add_tail(&e
->base
.link
, &dev
->vblank_event_list
);
1102 vblwait
->reply
.sequence
= vblwait
->request
.sequence
;
1105 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1110 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1113 drm_vblank_put(dev
, pipe
);
1120 * \param inode device inode.
1121 * \param file_priv DRM file private.
1122 * \param cmd command.
1123 * \param data user argument, pointing to a drm_wait_vblank structure.
1124 * \return zero on success or a negative number on failure.
1126 * This function enables the vblank interrupt on the pipe requested, then
1127 * sleeps waiting for the requested sequence number to occur, and drops
1128 * the vblank interrupt refcount afterwards. (vblank irq disable follows that
1129 * after a timeout with no further vblank waits scheduled).
1131 int drm_wait_vblank(struct drm_device
*dev
, void *data
,
1132 struct drm_file
*file_priv
)
1134 union drm_wait_vblank
*vblwait
= data
;
1136 unsigned int flags
, seq
, crtc
;
1138 if ((!drm_dev_to_irq(dev
)) || (!dev
->irq_enabled
))
1141 if (vblwait
->request
.type
& _DRM_VBLANK_SIGNAL
)
1144 if (vblwait
->request
.type
&
1145 ~(_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
)) {
1146 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
1147 vblwait
->request
.type
,
1148 (_DRM_VBLANK_TYPES_MASK
| _DRM_VBLANK_FLAGS_MASK
));
1152 flags
= vblwait
->request
.type
& _DRM_VBLANK_FLAGS_MASK
;
1153 crtc
= flags
& _DRM_VBLANK_SECONDARY
? 1 : 0;
1155 if (crtc
>= dev
->num_crtcs
)
1158 ret
= drm_vblank_get(dev
, crtc
);
1160 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret
);
1163 seq
= drm_vblank_count(dev
, crtc
);
1165 switch (vblwait
->request
.type
& _DRM_VBLANK_TYPES_MASK
) {
1166 case _DRM_VBLANK_RELATIVE
:
1167 vblwait
->request
.sequence
+= seq
;
1168 vblwait
->request
.type
&= ~_DRM_VBLANK_RELATIVE
;
1169 case _DRM_VBLANK_ABSOLUTE
:
1176 if (flags
& _DRM_VBLANK_EVENT
)
1177 return drm_queue_vblank_event(dev
, crtc
, vblwait
, file_priv
);
1179 if ((flags
& _DRM_VBLANK_NEXTONMISS
) &&
1180 (seq
- vblwait
->request
.sequence
) <= (1<<23)) {
1181 vblwait
->request
.sequence
= seq
+ 1;
1184 DRM_DEBUG("waiting on vblank count %d, crtc %d\n",
1185 vblwait
->request
.sequence
, crtc
);
1186 dev
->last_vblank_wait
[crtc
] = vblwait
->request
.sequence
;
1187 DRM_WAIT_ON(ret
, dev
->vbl_queue
[crtc
], 3 * DRM_HZ
,
1188 (((drm_vblank_count(dev
, crtc
) -
1189 vblwait
->request
.sequence
) <= (1 << 23)) ||
1190 !dev
->irq_enabled
));
1192 if (ret
!= -EINTR
) {
1195 vblwait
->reply
.sequence
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1196 vblwait
->reply
.tval_sec
= now
.tv_sec
;
1197 vblwait
->reply
.tval_usec
= now
.tv_usec
;
1199 DRM_DEBUG("returning %d to client\n",
1200 vblwait
->reply
.sequence
);
1202 DRM_DEBUG("vblank wait interrupted by signal\n");
1206 drm_vblank_put(dev
, crtc
);
1210 void drm_handle_vblank_events(struct drm_device
*dev
, int crtc
)
1212 struct drm_pending_vblank_event
*e
, *t
;
1214 unsigned long flags
;
1217 seq
= drm_vblank_count_and_time(dev
, crtc
, &now
);
1219 spin_lock_irqsave(&dev
->event_lock
, flags
);
1221 list_for_each_entry_safe(e
, t
, &dev
->vblank_event_list
, base
.link
) {
1222 if (e
->pipe
!= crtc
)
1224 if ((seq
- e
->event
.sequence
) > (1<<23))
1227 DRM_DEBUG("vblank event on %d, current %d\n",
1228 e
->event
.sequence
, seq
);
1230 e
->event
.sequence
= seq
;
1231 e
->event
.tv_sec
= now
.tv_sec
;
1232 e
->event
.tv_usec
= now
.tv_usec
;
1233 drm_vblank_put(dev
, e
->pipe
);
1234 list_move_tail(&e
->base
.link
, &e
->base
.file_priv
->event_list
);
1235 wake_up_interruptible(&e
->base
.file_priv
->event_wait
);
1236 trace_drm_vblank_event_delivered(e
->base
.pid
, e
->pipe
,
1240 spin_unlock_irqrestore(&dev
->event_lock
, flags
);
1242 trace_drm_vblank_event(crtc
, seq
);
1246 * drm_handle_vblank - handle a vblank event
1248 * @crtc: where this event occurred
1250 * Drivers should call this routine in their vblank interrupt handlers to
1251 * update the vblank counter and send any signals that may be pending.
1253 void drm_handle_vblank(struct drm_device
*dev
, int crtc
)
1257 struct timeval tvblank
;
1258 unsigned long irqflags
;
1260 if (!dev
->num_crtcs
)
1263 /* Need timestamp lock to prevent concurrent execution with
1264 * vblank enable/disable, as this would cause inconsistent
1265 * or corrupted timestamps and vblank counts.
1267 spin_lock_irqsave(&dev
->vblank_time_lock
, irqflags
);
1269 /* Vblank irq handling disabled. Nothing to do. */
1270 if (!dev
->vblank_enabled
[crtc
]) {
1271 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1275 /* Fetch corresponding timestamp for this vblank interval from
1276 * driver and store it in proper slot of timestamp ringbuffer.
1279 /* Get current timestamp and count. */
1280 vblcount
= atomic_read(&dev
->_vblank_count
[crtc
]);
1281 drm_get_last_vbltimestamp(dev
, crtc
, &tvblank
, DRM_CALLED_FROM_VBLIRQ
);
1283 /* Compute time difference to timestamp of last vblank */
1284 diff_ns
= timeval_to_ns(&tvblank
) -
1285 timeval_to_ns(&vblanktimestamp(dev
, crtc
, vblcount
));
1287 /* Update vblank timestamp and count if at least
1288 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds
1289 * difference between last stored timestamp and current
1290 * timestamp. A smaller difference means basically
1291 * identical timestamps. Happens if this vblank has
1292 * been already processed and this is a redundant call,
1293 * e.g., due to spurious vblank interrupts. We need to
1294 * ignore those for accounting.
1296 if (abs(diff_ns
) > DRM_REDUNDANT_VBLIRQ_THRESH_NS
) {
1297 /* Store new timestamp in ringbuffer. */
1298 vblanktimestamp(dev
, crtc
, vblcount
+ 1) = tvblank
;
1301 /* Increment cooked vblank count. This also atomically commits
1302 * the timestamp computed above.
1304 atomic_inc(&dev
->_vblank_count
[crtc
]);
1306 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n",
1307 crtc
, (int) diff_ns
);
1310 DRM_WAKEUP(&dev
->vbl_queue
[crtc
]);
1311 drm_handle_vblank_events(dev
, crtc
);
1313 spin_unlock_irqrestore(&dev
->vblank_time_lock
, irqflags
);
1315 EXPORT_SYMBOL(drm_handle_vblank
);