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i915_vblank_tasklet: Try harder to avoid tearing. 

Previously, if there were several buffer swaps scheduled for the same vertical
blank, all but the first blit emitted stood a chance of exhibiting tearing. In
order to avoid this, split the blits along slices of each output top to bottom.

Signed-off-by: Dave Airlie <airlied@linux.ie>
hifive-unleashed-5.1
=?utf-8?q?Michel_D=C3=A4nzer?= 2006-12-11 18:32:27 +11:00 committed by Dave Airlie
parent 2c3f0eddfb
commit 3188a24c25
1 changed files with 140 additions and 61 deletions
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201
drivers/char/drm/i915_irq.c
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@ -46,88 +46,167 @@ static void i915_vblank_tasklet(drm_device_t *dev)
{
drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
unsigned long irqflags;
struct list_head *list, *tmp;
struct list_head *list, *tmp, hits, *hit;
int nhits, nrects, slice[2], upper[2], lower[2], i;
unsigned counter[2] = { atomic_read(&dev->vbl_received),
atomic_read(&dev->vbl_received2) };
drm_drawable_info_t *drw;
drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
u32 cpp = dev_priv->cpp;
u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
XY_SRC_COPY_BLT_WRITE_ALPHA |
XY_SRC_COPY_BLT_WRITE_RGB)
: XY_SRC_COPY_BLT_CMD;
u32 pitchropcpp = (sarea_priv->pitch * cpp) | (0xcc << 16) |
(cpp << 23) | (1 << 24);
RING_LOCALS;
DRM_DEBUG("\n");
INIT_LIST_HEAD(&hits);
nhits = nrects = 0;
spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
/* Find buffer swaps scheduled for this vertical blank */
list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
drm_i915_vbl_swap_t *vbl_swap =
list_entry(list, drm_i915_vbl_swap_t, head);
atomic_t *counter = vbl_swap->pipe ? &dev->vbl_received2 :
&dev->vbl_received;
if ((atomic_read(counter) - vbl_swap->sequence) <= (1<<23)) {
drm_drawable_info_t *drw;
if ((counter[vbl_swap->pipe] - vbl_swap->sequence) > (1<<23))
continue;
spin_unlock(&dev_priv->swaps_lock);
list_del(list);
dev_priv->swaps_pending--;
spin_lock(&dev->drw_lock);
spin_unlock(&dev_priv->swaps_lock);
spin_lock(&dev->drw_lock);
drw = drm_get_drawable_info(dev, vbl_swap->drw_id);
if (drw) {
int i, num_rects = drw->num_rects;
drm_clip_rect_t *rect = drw->rects;
drm_i915_sarea_t *sarea_priv =
dev_priv->sarea_priv;
u32 cpp = dev_priv->cpp;
u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
XY_SRC_COPY_BLT_WRITE_ALPHA |
XY_SRC_COPY_BLT_WRITE_RGB)
: XY_SRC_COPY_BLT_CMD;
u32 pitchropcpp = (sarea_priv->pitch * cpp) |
(0xcc << 16) | (cpp << 23) |
(1 << 24);
RING_LOCALS;
drw = drm_get_drawable_info(dev, vbl_swap->drw_id);
i915_kernel_lost_context(dev);
if (!drw) {
spin_unlock(&dev->drw_lock);
drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
spin_lock(&dev_priv->swaps_lock);
continue;
}
BEGIN_LP_RING(6);
list_for_each(hit, &hits) {
drm_i915_vbl_swap_t *swap_cmp =
list_entry(hit, drm_i915_vbl_swap_t, head);
drm_drawable_info_t *drw_cmp =
drm_get_drawable_info(dev, swap_cmp->drw_id);
OUT_RING(GFX_OP_DRAWRECT_INFO);
OUT_RING(0);
OUT_RING(0);
OUT_RING(sarea_priv->width |
sarea_priv->height << 16);
OUT_RING(sarea_priv->width |
sarea_priv->height << 16);
OUT_RING(0);
if (drw_cmp &&
drw_cmp->rects[0].y1 > drw->rects[0].y1) {
list_add_tail(list, hit);
break;
}
}
spin_unlock(&dev->drw_lock);
/* List of hits was empty, or we reached the end of it */
if (hit == &hits)
list_add_tail(list, hits.prev);
nhits++;
spin_lock(&dev_priv->swaps_lock);
}
if (nhits == 0) {
spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
return;
}
spin_unlock(&dev_priv->swaps_lock);
i915_kernel_lost_context(dev);
BEGIN_LP_RING(6);
OUT_RING(GFX_OP_DRAWRECT_INFO);
OUT_RING(0);
OUT_RING(0);
OUT_RING(sarea_priv->width | sarea_priv->height << 16);
OUT_RING(sarea_priv->width | sarea_priv->height << 16);
OUT_RING(0);
ADVANCE_LP_RING();
sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;
upper[0] = upper[1] = 0;
slice[0] = max(sarea_priv->pipeA_h / nhits, 1);
slice[1] = max(sarea_priv->pipeB_h / nhits, 1);
lower[0] = sarea_priv->pipeA_y + slice[0];
lower[1] = sarea_priv->pipeB_y + slice[0];
spin_lock(&dev->drw_lock);
/* Emit blits for buffer swaps, partitioning both outputs into as many
* slices as there are buffer swaps scheduled in order to avoid tearing
* (based on the assumption that a single buffer swap would always
* complete before scanout starts).
*/
for (i = 0; i++ < nhits;
upper[0] = lower[0], lower[0] += slice[0],
upper[1] = lower[1], lower[1] += slice[1]) {
if (i == nhits)
lower[0] = lower[1] = sarea_priv->height;
list_for_each(hit, &hits) {
drm_i915_vbl_swap_t *swap_hit =
list_entry(hit, drm_i915_vbl_swap_t, head);
drm_clip_rect_t *rect;
int num_rects, pipe;
unsigned short top, bottom;
drw = drm_get_drawable_info(dev, swap_hit->drw_id);
if (!drw)
continue;
rect = drw->rects;
pipe = swap_hit->pipe;
top = upper[pipe];
bottom = lower[pipe];
for (num_rects = drw->num_rects; num_rects--; rect++) {
int y1 = max(rect->y1, top);
int y2 = min(rect->y2, bottom);
if (y1 >= y2)
continue;
BEGIN_LP_RING(8);
OUT_RING(cmd);
OUT_RING(pitchropcpp);
OUT_RING((y1 << 16) | rect->x1);
OUT_RING((y2 << 16) | rect->x2);
OUT_RING(sarea_priv->front_offset);
OUT_RING((y1 << 16) | rect->x1);
OUT_RING(pitchropcpp & 0xffff);
OUT_RING(sarea_priv->back_offset);
ADVANCE_LP_RING();
sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;
for (i = 0; i < num_rects; i++, rect++) {
BEGIN_LP_RING(8);
OUT_RING(cmd);
OUT_RING(pitchropcpp);
OUT_RING((rect->y1 << 16) | rect->x1);
OUT_RING((rect->y2 << 16) | rect->x2);
OUT_RING(sarea_priv->front_offset);
OUT_RING((rect->y1 << 16) | rect->x1);
OUT_RING(pitchropcpp & 0xffff);
OUT_RING(sarea_priv->back_offset);
ADVANCE_LP_RING();
}
}
spin_unlock(&dev->drw_lock);
spin_lock(&dev_priv->swaps_lock);
list_del(list);
drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
dev_priv->swaps_pending--;
}
}
spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
spin_unlock_irqrestore(&dev->drw_lock, irqflags);
list_for_each_safe(hit, tmp, &hits) {
drm_i915_vbl_swap_t *swap_hit =
list_entry(hit, drm_i915_vbl_swap_t, head);
list_del(hit);
drm_free(swap_hit, sizeof(*swap_hit), DRM_MEM_DRIVER);
}
}
irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)