etnaviv: Disable seamless cube map on GC880

The GC880 on iMX6DL indicates in it's minorFeatures2 register that it
does support SEAMLESS_CUBE_MAP, however when the TE.SAMPLER_CONFIG1
VIVS_TE_SAMPLER_CONFIG1_SEAMLESS_CUBE_MAP bit is set on GC880 on iMX6DL,
the result is corrupted image. In particular, the following ~112 dEQPs
are affected and fail:

  dEQP-GLES2.functional.texture.filtering.cube.*

This only happens on MX6DL GC880, MX6Q GC2000 and STM32MP1 GC400(GCnano)
do not report the minorFeatures2 SEAMLESS_CUBE_MAP bit and ignore the
TE_SAMPLER_CONFIG1 VIVS_TE_SAMPLER_CONFIG1_SEAMLESS_CUBE_MAP bit (note
that ss->seamless_cube_map is unconditionally set by mesa at times even
PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE returns 0), so there is no visible
problem and there are no failing dEQP tests on the GC2000 and GCnano.

This might imply that the minorFeatures2 SEAMLESS_CUBE_MAP has some
different meaning on GC880 or the SEAMLESS_CUBE_MAP behaves differently
on the GC880.

This patch does not set the SEAMLESS_CUBE_MAP bit on hardware which does
not indicate support for seamless cube map and on GC880, which results
in reduction in failed dEQPs: 635 to 186 on GC880, 274 to 270 on GC2000
and no change on GC400(GCnano).

Fixes: 8dd26fa2f06 ("etnaviv: support GL_ARB_seamless_cubemap_per_texture")
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4865>

3 files changed, 10 insertions, 3 deletions

diff --git a/src/gallium/drivers/etnaviv/etnaviv_internal.h b/src/gallium/drivers/etnaviv/etnaviv_internal.h
index fabd43199ee..dc5f3f2b902 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_internal.h
+++ b/src/gallium/drivers/etnaviv/etnaviv_internal.h
@@ -91,6 +91,8 @@ struct etna_specs {
    unsigned use_blt : 1;
    /* can use any kind of wrapping mode on npot textures */
    unsigned npot_tex_any_wrap : 1;
+   /* supports seamless cube map */
+   unsigned seamless_cube_map : 1;
    /* number of bits per TS tile */
    unsigned bits_per_tile;
    /* clear value for TS (dependent on bits_per_tile) */
diff --git a/src/gallium/drivers/etnaviv/etnaviv_screen.c b/src/gallium/drivers/etnaviv/etnaviv_screen.c
index 338b643c7be..9fbacd3c49b 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_screen.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_screen.c
@@ -220,7 +220,7 @@ etna_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
    case PIPE_CAP_MAX_TEXEL_OFFSET:
       return 7;
    case PIPE_CAP_SEAMLESS_CUBE_MAP_PER_TEXTURE:
-      return VIV_FEATURE(screen, chipMinorFeatures2, SEAMLESS_CUBE_MAP);
+      return screen->specs.seamless_cube_map;
 
    /* Timer queries. */
    case PIPE_CAP_OCCLUSION_QUERY:
@@ -763,6 +763,9 @@ etna_get_specs(struct etna_screen *screen)
       VIV_FEATURE(screen, chipMinorFeatures4, HALTI2);
    screen->specs.v4_compression =
       VIV_FEATURE(screen, chipMinorFeatures6, V4_COMPRESSION);
+   screen->specs.seamless_cube_map =
+      (screen->model != 0x880) && /* Seamless cubemap is broken on GC880? */
+      VIV_FEATURE(screen, chipMinorFeatures2, SEAMLESS_CUBE_MAP);
 
    if (screen->specs.halti >= 5) {
       /* GC7000 - this core must load shaders from memory. */
diff --git a/src/gallium/drivers/etnaviv/etnaviv_texture_state.c b/src/gallium/drivers/etnaviv/etnaviv_texture_state.c
index c66bfcee9a8..4c11b114ac0 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_texture_state.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_texture_state.c
@@ -86,6 +86,8 @@ etna_create_sampler_state_state(struct pipe_context *pipe,
                           const struct pipe_sampler_state *ss)
 {
    struct etna_sampler_state *cs = CALLOC_STRUCT(etna_sampler_state);
+   struct etna_context *ctx = etna_context(pipe);
+   struct etna_screen *screen = ctx->screen;
    const bool ansio = ss->max_anisotropy > 1;
 
    if (!cs)
@@ -105,8 +107,8 @@ etna_create_sampler_state_state(struct pipe_context *pipe,
       cs->TE_SAMPLER_CONFIG0 |= VIVS_TE_SAMPLER_CONFIG0_ROUND_UV;
    }
 
-   cs->TE_SAMPLER_CONFIG1 =
-      COND(ss->seamless_cube_map, VIVS_TE_SAMPLER_CONFIG1_SEAMLESS_CUBE_MAP);
+   cs->TE_SAMPLER_CONFIG1 = screen->specs.seamless_cube_map ?
+      COND(ss->seamless_cube_map, VIVS_TE_SAMPLER_CONFIG1_SEAMLESS_CUBE_MAP) : 0;
 
    cs->TE_SAMPLER_LOD_CONFIG =
       COND(ss->lod_bias != 0.0, VIVS_TE_SAMPLER_LOD_CONFIG_BIAS_ENABLE) |