drm/i915/sprite: Avoid incurring extra vblank stall when updating plane on IVB
IvyBridge requires an extra frame between disabling the low power
watermarks and enabling scaling on the sprite plane. If the scaling
is already enabled, then we have already disabled the low power
watermarks and need not incur an extra wait.
Similarly, as we disable the scaling when turning off the sprite plane,
we can update the scaling enabled flag and restore the low power
watermarks.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index fbf03b9..4431567 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -110,14 +110,18 @@
* when scaling is disabled.
*/
if (crtc_w != src_w || crtc_h != src_h) {
- dev_priv->sprite_scaling_enabled = true;
- intel_update_watermarks(dev);
- intel_wait_for_vblank(dev, pipe);
+ if (!dev_priv->sprite_scaling_enabled) {
+ dev_priv->sprite_scaling_enabled = true;
+ intel_update_watermarks(dev);
+ intel_wait_for_vblank(dev, pipe);
+ }
sprscale = SPRITE_SCALE_ENABLE | (src_w << 16) | src_h;
} else {
- dev_priv->sprite_scaling_enabled = false;
- /* potentially re-enable LP watermarks */
- intel_update_watermarks(dev);
+ if (dev_priv->sprite_scaling_enabled) {
+ dev_priv->sprite_scaling_enabled = false;
+ /* potentially re-enable LP watermarks */
+ intel_update_watermarks(dev);
+ }
}
I915_WRITE(SPRSTRIDE(pipe), fb->pitches[0]);
@@ -151,6 +155,9 @@
/* Activate double buffered register update */
I915_MODIFY_DISPBASE(SPRSURF(pipe), 0);
POSTING_READ(SPRSURF(pipe));
+
+ dev_priv->sprite_scaling_enabled = false;
+ intel_update_watermarks(dev);
}
static int