drm/i915: Avoid underruns when disabling sprites
As the watermark registers aren't double bufferd, clearing the
watermarks immediately after writing the sprite registers can be
hazardous.
Until we have something better, add a wait for vblank between the
two steps to make sure the sprite no longer needs the watermark
levels before we clear them.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
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 050ec29..606c27b 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -336,6 +336,12 @@
I915_MODIFY_DISPBASE(SPRSURF(pipe), 0);
POSTING_READ(SPRSURF(pipe));
+ /*
+ * Avoid underruns when disabling the sprite.
+ * FIXME remove once watermark updates are done properly.
+ */
+ intel_wait_for_vblank(dev, pipe);
+
intel_update_sprite_watermarks(plane, crtc, 0, 0, false, false);
}
@@ -503,6 +509,12 @@
I915_MODIFY_DISPBASE(DVSSURF(pipe), 0);
POSTING_READ(DVSSURF(pipe));
+ /*
+ * Avoid underruns when disabling the sprite.
+ * FIXME remove once watermark updates are done properly.
+ */
+ intel_wait_for_vblank(dev, pipe);
+
intel_update_sprite_watermarks(plane, crtc, 0, 0, false, false);
}