radeonsi: set CB_BLEND1_CONTROL.ENABLE for dual source blending

copied from Vulkan

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

diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index 47b1148..911e979 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -454,6 +454,10 @@ static void *si_create_blend_state_mode(struct pipe_context *ctx,
 
                /* Only set dual source blending for MRT0 to avoid a hang. */
                if (i >= 1 && blend->dual_src_blend) {
+                       /* Vulkan does this for dual source blending. */
+                       if (i == 1)
+                               blend_cntl |= S_028780_ENABLE(1);
+
                        si_pm4_set_reg(pm4, R_028780_CB_BLEND0_CONTROL + i * 4, blend_cntl);
                        continue;
                }