radeonsi/gfx9: disable the 2-bit format fetch fix

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 ae5aac0..b120e9a 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -3342,6 +3342,7 @@ 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;
@@ -3381,9 +3382,12 @@ static void *si_create_vertex_elements(struct pipe_context *ctx,
                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) {