From 2fefee6015ed2df52c8513ae180ca83c01ff83c0 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 6 Jan 2012 12:10:27 +0000
Subject: [PATCH] sna/gen6: Reuse current no-blending setup for PictOpClear

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 src/sna/gen6_render.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/sna/gen6_render.c b/src/sna/gen6_render.c
index bb0aab1f..d35942c3 100644
--- a/src/sna/gen6_render.c
+++ b/src/sna/gen6_render.c
@@ -585,6 +585,17 @@ gen6_emit_cc(struct sna *sna,
 	if (render->blend == blend)
 		return false;
 
+	if (op == PictOpClear) {
+		uint32_t src;
+
+		/* We can emulate a clear using src, which is beneficial if
+		 * the blend unit is already disabled.
+		 */
+		src = BLEND_OFFSET(GEN6_BLENDFACTOR_ONE, GEN6_BLENDFACTOR_ZERO);
+		if (render->blend == src)
+			return false;
+	}
+
 	OUT_BATCH(GEN6_3DSTATE_CC_STATE_POINTERS | (4 - 2));
 	OUT_BATCH((render->cc_blend + blend) | 1);
 	if (render->blend == (unsigned)-1) {