[Freedreno] [PATCH] freedreno/a4xx: fix dst_alpha blend for RGBX render targets

[Ilia Mirkin]

There are not native RGBX render formats, so we must manually force
dst_alpha to be one, same as for a3xx.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/drivers/freedreno/a4xx/fd4_blend.c | 13 +++++++++++--
 src/gallium/drivers/freedreno/a4xx/fd4_blend.h |  7 ++++++-
 src/gallium/drivers/freedreno/a4xx/fd4_emit.c  | 17 +++++++++++++++--
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/freedreno/a4xx/fd4_blend.c b/src/gallium/drivers/freedreno/a4xx/fd4_blend.c
index eb84ba1..03c1a37 100644
--- a/src/gallium/drivers/freedreno/a4xx/fd4_blend.c
+++ b/src/gallium/drivers/freedreno/a4xx/fd4_blend.c
@@ -27,6 +27,7 @@
  */
 
 #include "pipe/p_state.h"
+#include "util/u_blend.h"
 #include "util/u_string.h"
 #include "util/u_memory.h"
 
@@ -98,14 +99,22 @@ fd4_blend_state_create(struct pipe_context *pctx,
 		else
 			rt = &cso->rt[0];
 
-		so->rb_mrt[i].blend_control =
+		so->rb_mrt[i].blend_control_rgb =
 				A4XX_RB_MRT_BLEND_CONTROL_RGB_SRC_FACTOR(fd_blend_factor(rt->rgb_src_factor)) |
 				A4XX_RB_MRT_BLEND_CONTROL_RGB_BLEND_OPCODE(blend_func(rt->rgb_func)) |
-				A4XX_RB_MRT_BLEND_CONTROL_RGB_DEST_FACTOR(fd_blend_factor(rt->rgb_dst_factor)) |
+				A4XX_RB_MRT_BLEND_CONTROL_RGB_DEST_FACTOR(fd_blend_factor(rt->rgb_dst_factor));
+
+		so->rb_mrt[i].blend_control_alpha =
 				A4XX_RB_MRT_BLEND_CONTROL_ALPHA_SRC_FACTOR(fd_blend_factor(rt->alpha_src_factor)) |
 				A4XX_RB_MRT_BLEND_CONTROL_ALPHA_BLEND_OPCODE(blend_func(rt->alpha_func)) |
 				A4XX_RB_MRT_BLEND_CONTROL_ALPHA_DEST_FACTOR(fd_blend_factor(rt->alpha_dst_factor));
 
+		so->rb_mrt[i].blend_control_no_alpha_rgb =
+				A4XX_RB_MRT_BLEND_CONTROL_RGB_SRC_FACTOR(fd_blend_factor(util_blend_dst_alpha_to_one(rt->rgb_src_factor))) |
+				A4XX_RB_MRT_BLEND_CONTROL_RGB_BLEND_OPCODE(blend_func(rt->rgb_func)) |
+				A4XX_RB_MRT_BLEND_CONTROL_RGB_DEST_FACTOR(fd_blend_factor(util_blend_dst_alpha_to_one(rt->rgb_dst_factor)));
+
+
 		so->rb_mrt[i].control =
 				A4XX_RB_MRT_CONTROL_ROP_CODE(rop) |
 				COND(cso->logicop_enable, A4XX_RB_MRT_CONTROL_ROP_ENABLE) |
diff --git a/src/gallium/drivers/freedreno/a4xx/fd4_blend.h b/src/gallium/drivers/freedreno/a4xx/fd4_blend.h
index 7620d00..6230fa7 100644
--- a/src/gallium/drivers/freedreno/a4xx/fd4_blend.h
+++ b/src/gallium/drivers/freedreno/a4xx/fd4_blend.h
@@ -39,7 +39,12 @@ struct fd4_blend_stateobj {
 	struct {
 		uint32_t control;
 		uint32_t buf_info;
-		uint32_t blend_control;
+		/* Blend control bits for color if there is an alpha channel */
+		uint32_t blend_control_rgb;
+		/* Blend control bits for color if there is no alpha channel */
+		uint32_t blend_control_no_alpha_rgb;
+		/* Blend control bits for alpha channel */
+		uint32_t blend_control_alpha;
 	} rb_mrt[A4XX_MAX_RENDER_TARGETS];
 	uint32_t rb_fs_output;
 };
diff --git a/src/gallium/drivers/freedreno/a4xx/fd4_emit.c b/src/gallium/drivers/freedreno/a4xx/fd4_emit.c
index 5a7b192..99d1602 100644
--- a/src/gallium/drivers/freedreno/a4xx/fd4_emit.c
+++ b/src/gallium/drivers/freedreno/a4xx/fd4_emit.c
@@ -626,11 +626,24 @@ fd4_emit_state(struct fd_context *ctx, struct fd_ringbuffer *ring,
 		uint32_t i;
 
 		for (i = 0; i < A4XX_MAX_RENDER_TARGETS; i++) {
+			enum pipe_format format = pipe_surface_format(
+					ctx->framebuffer.cbufs[i]);
+			bool has_alpha = util_format_has_alpha(format);
+			uint32_t control = blend->rb_mrt[i].control;
+			uint32_t blend_control = blend->rb_mrt[i].blend_control_alpha;
+
+			if (has_alpha) {
+				blend_control |= blend->rb_mrt[i].blend_control_rgb;
+			} else {
+				blend_control |= blend->rb_mrt[i].blend_control_no_alpha_rgb;
+				control &= ~A4XX_RB_MRT_CONTROL_BLEND2;
+			}
+
 			OUT_PKT0(ring, REG_A4XX_RB_MRT_CONTROL(i), 1);
-			OUT_RING(ring, blend->rb_mrt[i].control);
+			OUT_RING(ring, control);
 
 			OUT_PKT0(ring, REG_A4XX_RB_MRT_BLEND_CONTROL(i), 1);
-			OUT_RING(ring, blend->rb_mrt[i].blend_control);
+			OUT_RING(ring, blend_control);
 		}
 
 		OUT_PKT0(ring, REG_A4XX_RB_FS_OUTPUT, 1);
-- 
2.4.10