[PATCH 4/6] drm/radeon: Provide page_flip_target hook
Michel Dänzer
michel at daenzer.net
Thu Aug 4 03:39:39 UTC 2016
From: Michel Dänzer <michel.daenzer at amd.com>
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.
Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
drivers/gpu/drm/radeon/radeon.h | 1 +
drivers/gpu/drm/radeon/radeon_display.c | 89 +++++++++------------------------
2 files changed, 25 insertions(+), 65 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 5633ee3..1b0dcad 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -742,6 +742,7 @@ struct radeon_flip_work {
struct work_struct unpin_work;
struct radeon_device *rdev;
int crtc_id;
+ u32 target_vblank;
uint64_t base;
struct drm_pending_vblank_event *event;
struct radeon_bo *old_rbo;
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 5f1cd69..bd9d995 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -400,14 +400,13 @@ static void radeon_flip_work_func(struct work_struct *__work)
struct radeon_flip_work *work =
container_of(__work, struct radeon_flip_work, flip_work);
struct radeon_device *rdev = work->rdev;
+ struct drm_device *dev = rdev->ddev;
struct radeon_crtc *radeon_crtc = rdev->mode_info.crtcs[work->crtc_id];
struct drm_crtc *crtc = &radeon_crtc->base;
unsigned long flags;
int r;
- int vpos, hpos, stat, min_udelay = 0;
- unsigned repcnt = 4;
- struct drm_vblank_crtc *vblank = &crtc->dev->vblank[work->crtc_id];
+ int vpos, hpos;
down_read(&rdev->exclusive_lock);
if (work->fence) {
@@ -438,59 +437,25 @@ static void radeon_flip_work_func(struct work_struct *__work)
work->fence = NULL;
}
+ /* Wait until we're out of the vertical blank period before the one
+ * targeted by the flip
+ */
+ while (radeon_crtc->enabled &&
+ (radeon_get_crtc_scanoutpos(dev, work->crtc_id, 0,
+ &vpos, &hpos, NULL, NULL,
+ &crtc->hwmode)
+ & (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_IN_VBLANK)) ==
+ (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_IN_VBLANK) &&
+ (int)(work->target_vblank -
+ dev->driver->get_vblank_counter(dev, work->crtc_id)) > 0)
+ usleep_range(1000, 2000);
+
/* We borrow the event spin lock for protecting flip_status */
spin_lock_irqsave(&crtc->dev->event_lock, flags);
/* set the proper interrupt */
radeon_irq_kms_pflip_irq_get(rdev, radeon_crtc->crtc_id);
- /* If this happens to execute within the "virtually extended" vblank
- * interval before the start of the real vblank interval then it needs
- * to delay programming the mmio flip until the real vblank is entered.
- * This prevents completing a flip too early due to the way we fudge
- * our vblank counter and vblank timestamps in order to work around the
- * problem that the hw fires vblank interrupts before actual start of
- * vblank (when line buffer refilling is done for a frame). It
- * complements the fudging logic in radeon_get_crtc_scanoutpos() for
- * timestamping and radeon_get_vblank_counter_kms() for vblank counts.
- *
- * In practice this won't execute very often unless on very fast
- * machines because the time window for this to happen is very small.
- */
- while (radeon_crtc->enabled && --repcnt) {
- /* GET_DISTANCE_TO_VBLANKSTART returns distance to real vblank
- * start in hpos, and to the "fudged earlier" vblank start in
- * vpos.
- */
- stat = radeon_get_crtc_scanoutpos(rdev->ddev, work->crtc_id,
- GET_DISTANCE_TO_VBLANKSTART,
- &vpos, &hpos, NULL, NULL,
- &crtc->hwmode);
-
- if ((stat & (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE)) !=
- (DRM_SCANOUTPOS_VALID | DRM_SCANOUTPOS_ACCURATE) ||
- !(vpos >= 0 && hpos <= 0))
- break;
-
- /* Sleep at least until estimated real start of hw vblank */
- min_udelay = (-hpos + 1) * max(vblank->linedur_ns / 1000, 5);
- if (min_udelay > vblank->framedur_ns / 2000) {
- /* Don't wait ridiculously long - something is wrong */
- repcnt = 0;
- break;
- }
- spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
- usleep_range(min_udelay, 2 * min_udelay);
- spin_lock_irqsave(&crtc->dev->event_lock, flags);
- };
-
- if (!repcnt)
- DRM_DEBUG_DRIVER("Delay problem on crtc %d: min_udelay %d, "
- "framedur %d, linedur %d, stat %d, vpos %d, "
- "hpos %d\n", work->crtc_id, min_udelay,
- vblank->framedur_ns / 1000,
- vblank->linedur_ns / 1000, stat, vpos, hpos);
-
/* do the flip (mmio) */
radeon_page_flip(rdev, radeon_crtc->crtc_id, work->base, work->async);
@@ -499,10 +464,11 @@ static void radeon_flip_work_func(struct work_struct *__work)
up_read(&rdev->exclusive_lock);
}
-static int radeon_crtc_page_flip(struct drm_crtc *crtc,
- struct drm_framebuffer *fb,
- struct drm_pending_vblank_event *event,
- uint32_t page_flip_flags)
+static int radeon_crtc_page_flip_target(struct drm_crtc *crtc,
+ struct drm_framebuffer *fb,
+ struct drm_pending_vblank_event *event,
+ uint32_t page_flip_flags,
+ uint32_t target)
{
struct drm_device *dev = crtc->dev;
struct radeon_device *rdev = dev->dev_private;
@@ -599,12 +565,8 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
base &= ~7;
}
work->base = base;
-
- r = drm_crtc_vblank_get(crtc);
- if (r) {
- DRM_ERROR("failed to get vblank before flip\n");
- goto pflip_cleanup;
- }
+ work->target_vblank = target - drm_crtc_vblank_count(crtc) +
+ dev->driver->get_vblank_counter(dev, work->crtc_id);
/* We borrow the event spin lock for protecting flip_work */
spin_lock_irqsave(&crtc->dev->event_lock, flags);
@@ -613,7 +575,7 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
DRM_DEBUG_DRIVER("flip queue: crtc already busy\n");
spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
r = -EBUSY;
- goto vblank_cleanup;
+ goto pflip_cleanup;
}
radeon_crtc->flip_status = RADEON_FLIP_PENDING;
radeon_crtc->flip_work = work;
@@ -626,9 +588,6 @@ static int radeon_crtc_page_flip(struct drm_crtc *crtc,
queue_work(radeon_crtc->flip_queue, &work->flip_work);
return 0;
-vblank_cleanup:
- drm_crtc_vblank_put(crtc);
-
pflip_cleanup:
if (unlikely(radeon_bo_reserve(new_rbo, false) != 0)) {
DRM_ERROR("failed to reserve new rbo in error path\n");
@@ -697,7 +656,7 @@ static const struct drm_crtc_funcs radeon_crtc_funcs = {
.gamma_set = radeon_crtc_gamma_set,
.set_config = radeon_crtc_set_config,
.destroy = radeon_crtc_destroy,
- .page_flip = radeon_crtc_page_flip,
+ .page_flip_target = radeon_crtc_page_flip_target,
};
static void radeon_crtc_init(struct drm_device *dev, int index)
--
2.8.1
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