Skip to content

Commit b8fc75c

Browse files
Michel Dänzeralexdeucher
Michel Dänzer
authored and
alexdeucher
committed
drm/radeon: Provide page_flip_target hook
Now we can program a flip during a vertical blank period, if it's the one targeted by the flip (or a later one). This allows simplifying radeon_flip_work_func considerably. Acked-by: Christian König <christian.koenig@amd.com> Signed-off-by: Michel Dänzer <michel.daenzer@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 parent 3fd4b75 commit b8fc75c

File tree

2 files changed

+25
-65
lines changed

2 files changed

+25
-65
lines changed

‎drivers/gpu/drm/radeon/radeon.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -742,6 +742,7 @@ struct radeon_flip_work {
742742
struct work_struct unpin_work;
743743
struct radeon_device *rdev;
744744
int crtc_id;
745+
u32 target_vblank;
745746
uint64_t base;
746747
struct drm_pending_vblank_event *event;
747748
struct radeon_bo *old_rbo;

‎drivers/gpu/drm/radeon/radeon_display.c

Lines changed: 24 additions & 65 deletions
Original file line numberDiff line numberDiff line change
@@ -400,14 +400,13 @@ static void radeon_flip_work_func(struct work_struct *__work)
400400
struct radeon_flip_work *work =
401401
container_of(__work, struct radeon_flip_work, flip_work);
402402
struct radeon_device *rdev = work->rdev;
403+
struct drm_device *dev = rdev->ddev;
403404
struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[work->crtc_id];
404405

405406
struct drm_crtc *crtc = &radeon_crtc->base;
406407
unsigned long flags;
407408
int r;
408-
int vpos, hpos, stat, min_udelay = 0;
409-
unsigned repcnt = 4;
410-
struct drm_vblank_crtc *vblank = &crtc->dev->vblank[work->crtc_id];
409+
int vpos, hpos;
411410

412411
down_read(&rdev->exclusive_lock);
413412
if (work->fence) {
@@ -438,59 +437,25 @@ static void radeon_flip_work_func(struct work_struct *__work)
438437
work->fence = NULL;
439438
}
440439

440+
/* Wait until we're out of the vertical blank period before the one
441+
* targeted by the flip
442+
*/
443+
while (radeon_crtc->enabled &&
444+
(radeon_get_crtc_scanoutpos(dev, work->crtc_id, 0,
445+
&vpos, &hpos, NULL, NULL,
446+
&crtc->hwmode)
447+
& (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_IN_VBLANK)) ==
448+
(DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_IN_VBLANK) &&
449+
(int)(work->target_vblank -
450+
dev->driver->get_vblank_counter(dev, work->crtc_id)) > 0)
451+
usleep_range(1000, 2000);
452+
441453
/* We borrow the event spin lock for protecting flip_status */
442454
spin_lock_irqsave(&crtc->dev->event_lock, flags);
443455

444456
/* set the proper interrupt */
445457
radeon_irq_kms_pflip_irq_get(rdev, radeon_crtc->crtc_id);
446458

447-
/* If this happens to execute within the "virtually extended" vblank
448-
* interval before the start of the real vblank interval then it needs
449-
* to delay programming the mmio flip until the real vblank is entered.
450-
* This prevents completing a flip too early due to the way we fudge
451-
* our vblank counter and vblank timestamps in order to work around the
452-
* problem that the hw fires vblank interrupts before actual start of
453-
* vblank (when line buffer refilling is done for a frame). It
454-
* complements the fudging logic in radeon_get_crtc_scanoutpos() for
455-
* timestamping and radeon_get_vblank_counter_kms() for vblank counts.
456-
*
457-
* In practice this won't execute very often unless on very fast
458-
* machines because the time window for this to happen is very small.
459-
*/
460-
while (radeon_crtc->enabled && --repcnt) {
461-
/* GET_DISTANCE_TO_VBLANKSTART returns distance to real vblank
462-
* start in hpos, and to the "fudged earlier" vblank start in
463-
* vpos.
464-
*/
465-
stat = radeon_get_crtc_scanoutpos(rdev->ddev, work->crtc_id,
466-
GET_DISTANCE_TO_VBLANKSTART,
467-
&vpos, &hpos, NULL, NULL,
468-
&crtc->hwmode);
469-
470-
if ((stat & (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE)) !=
471-
(DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE) ||
472-
!(vpos >= 0 && hpos <= 0))
473-
break;
474-
475-
/* Sleep at least until estimated real start of hw vblank */
476-
min_udelay = (-hpos + 1) * max(vblank->linedur_ns / 1000, 5);
477-
if (min_udelay > vblank->framedur_ns / 2000) {
478-
/* Don't wait ridiculously long - something is wrong */
479-
repcnt = 0;
480-
break;
481-
}
482-
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
483-
usleep_range(min_udelay, 2 * min_udelay);
484-
spin_lock_irqsave(&crtc->dev->event_lock, flags);
485-
};
486-
487-
if (!repcnt)
488-
DRM_DEBUG_DRIVER("Delay problem on crtc %d: min_udelay %d, "
489-
"framedur %d, linedur %d, stat %d, vpos %d, "
490-
"hpos %d\n", work->crtc_id, min_udelay,
491-
vblank->framedur_ns / 1000,
492-
vblank->linedur_ns / 1000, stat, vpos, hpos);
493-
494459
/* do the flip (mmio) */
495460
radeon_page_flip(rdev, radeon_crtc->crtc_id, work->base, work->async);
496461

@@ -499,10 +464,11 @@ static void radeon_flip_work_func(struct work_struct *__work)
499464
up_read(&rdev->exclusive_lock);
500465
}
501466

502-
static int radeon_crtc_page_flip(struct drm_crtc *crtc,
503-
struct drm_framebuffer *fb,
504-
struct drm_pending_vblank_event *event,
505-
uint32_t page_flip_flags)
467+
static int radeon_crtc_page_flip_target(struct drm_crtc *crtc,
468+
struct drm_framebuffer *fb,
469+
struct drm_pending_vblank_event *event,
470+
uint32_t page_flip_flags,
471+
uint32_t target)
506472
{
507473
struct drm_device *dev = crtc->dev;
508474
struct radeon_device *rdev = dev->dev_private;
@@ -599,12 +565,8 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
599565
base &= ~7;
600566
}
601567
work->base = base;
602-
603-
r = drm_crtc_vblank_get(crtc);
604-
if (r) {
605-
DRM_ERROR("failed to get vblank before flip\n");
606-
goto pflip_cleanup;
607-
}
568+
work->target_vblank = target - drm_crtc_vblank_count(crtc) +
569+
dev->driver->get_vblank_counter(dev, work->crtc_id);
608570

609571
/* We borrow the event spin lock for protecting flip_work */
610572
spin_lock_irqsave(&crtc->dev->event_lock, flags);
@@ -613,7 +575,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
613575
DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
614576
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
615577
r = -EBUSY;
616-
goto vblank_cleanup;
578+
goto pflip_cleanup;
617579
}
618580
radeon_crtc->flip_status = RADEON_FLIP_PENDING;
619581
radeon_crtc->flip_work = work;
@@ -626,9 +588,6 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
626588
queue_work(radeon_crtc->flip_queue, &work->flip_work);
627589
return 0;
628590

629-
vblank_cleanup:
630-
drm_crtc_vblank_put(crtc);
631-
632591
pflip_cleanup:
633592
if (unlikely(radeon_bo_reserve(new_rbo, false) != 0)) {
634593
DRM_ERROR("failed to reserve new rbo in error path\n");
@@ -697,7 +656,7 @@ static const struct drm_crtc_funcs radeon_crtc_funcs = {
697656
.gamma_set = radeon_crtc_gamma_set,
698657
.set_config = radeon_crtc_set_config,
699658
.destroy = radeon_crtc_destroy,
700-
.page_flip = radeon_crtc_page_flip,
659+
.page_flip_target = radeon_crtc_page_flip_target,
701660
};
702661

703662
static void radeon_crtc_init(struct drm_device *dev, int index)

0 commit comments

Comments
 (0)