[Mesa-dev] [PATCH 084/140] radeonsi/gfx9: disable the 2-bit format fetch fix

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

---
 src/gallium/drivers/radeonsi/si_state.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index b7ba267..eacb1b4 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -3335,20 +3335,21 @@ static void si_delete_sampler_state(struct pipe_context *ctx, void *state)
 }
 
 /*
  * Vertex elements & buffers
  */
 
 static void *si_create_vertex_elements(struct pipe_context *ctx,
 				       unsigned count,
 				       const struct pipe_vertex_element *elements)
 {
+	struct si_screen *sscreen = (struct si_screen*)ctx->screen;
 	struct si_vertex_element *v = CALLOC_STRUCT(si_vertex_element);
 	bool used[SI_NUM_VERTEX_BUFFERS] = {};
 	int i;
 
 	assert(count <= SI_MAX_ATTRIBS);
 	if (!v)
 		return NULL;
 
 	v->count = count;
 	v->desc_list_byte_size = align(count * 16, SI_CPDMA_ALIGNMENT);
@@ -3374,23 +3375,26 @@ static void *si_create_vertex_elements(struct pipe_context *ctx,
 		desc = util_format_description(elements[i].src_format);
 		first_non_void = util_format_get_first_non_void_channel(elements[i].src_format);
 		data_format = si_translate_buffer_dataformat(ctx->screen, desc, first_non_void);
 		num_format = si_translate_buffer_numformat(ctx->screen, desc, first_non_void);
 		channel = first_non_void >= 0 ? &desc->channel[first_non_void] : NULL;
 		memcpy(swizzle, desc->swizzle, sizeof(swizzle));
 
 		v->format_size[i] = desc->block.bits / 8;
 
 		/* The hardware always treats the 2-bit alpha channel as
-		 * unsigned, so a shader workaround is needed.
+		 * unsigned, so a shader workaround is needed. The affected
+		 * chips are VI and older except Stoney (GFX8.1).
 		 */
-		if (data_format == V_008F0C_BUF_DATA_FORMAT_2_10_10_10) {
+		if (data_format == V_008F0C_BUF_DATA_FORMAT_2_10_10_10 &&
+		    sscreen->b.chip_class <= VI &&
+		    sscreen->b.family != CHIP_STONEY) {
 			if (num_format == V_008F0C_BUF_NUM_FORMAT_SNORM) {
 				v->fix_fetch[i] = SI_FIX_FETCH_A2_SNORM;
 			} else if (num_format == V_008F0C_BUF_NUM_FORMAT_SSCALED) {
 				v->fix_fetch[i] = SI_FIX_FETCH_A2_SSCALED;
 			} else if (num_format == V_008F0C_BUF_NUM_FORMAT_SINT) {
 				/* This isn't actually used in OpenGL. */
 				v->fix_fetch[i] = SI_FIX_FETCH_A2_SINT;
 			}
 		} else if (channel && channel->type == UTIL_FORMAT_TYPE_FIXED) {
 			if (desc->swizzle[3] == PIPE_SWIZZLE_1)
-- 
2.7.4