Mesa (master): radeonsi: disable RB+ blend optimizations for dual source blending

[Marek Olšák]

Module: Mesa
Branch: master
Commit: 5e5573b1bf8565f38e9b770b5357d069e80ff00d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5e5573b1bf8565f38e9b770b5357d069e80ff00d

Author: Marek Olšák <marek.olsak at amd.com>
Date:   Sat Nov 26 15:52:05 2016 +0100

radeonsi: disable RB+ blend optimizations for dual source blending

This fixes dual source blending on Stoney. The fix was copied from Vulkan.
The problem was discovered during internal testing.

Cc: 13.0 <mesa-stable at lists.freedesktop.org>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle at amd.com>

---

 src/gallium/drivers/radeonsi/si_state.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index 911e979..1ccf5b6 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -557,6 +557,17 @@ static void *si_create_blend_state_mode(struct pipe_context *ctx,
 	}
 
 	if (sctx->b.family == CHIP_STONEY) {
+		/* Disable RB+ blend optimizations for dual source blending.
+		 * Vulkan does this.
+		 */
+		if (blend->dual_src_blend) {
+			for (int i = 0; i < 8; i++) {
+				sx_mrt_blend_opt[i] =
+					S_028760_COLOR_COMB_FCN(V_028760_OPT_COMB_NONE) |
+					S_028760_ALPHA_COMB_FCN(V_028760_OPT_COMB_NONE);
+			}
+		}
+
 		for (int i = 0; i < 8; i++)
 			si_pm4_set_reg(pm4, R_028760_SX_MRT0_BLEND_OPT + i * 4,
 				       sx_mrt_blend_opt[i]);