[Mesa-dev] [PATCH] [v2] i965: Fix texture views of 2d array surfaces

[Ben Widawsky]

It is legal to have a texture view of a single layer from a 2D array texture;
you can sample from it, or render to it. Intel hardware needs to be made aware
when it is using a 2d array surface in the surface state. The texture view is
just a 2d surface with the backing miptree actually being a 2d array surface.
This caused the previous code would not set the right bit in the surface state
since it wasn't considered an array texture.

I spotted this early on in debug but brushed it off because it is clearly not
needed on other platforms (since they all pass). I have no idea how this works
properly on other platforms (I think gen7 introduced the bit in the state, but I
am too lazy to check). As such, I have opted not to modify gen7, though I
believe the current code is wrong there as well.

Thanks to Chris for helping me debug this.

v2: Just use the underlying mt's target type to make the array determination.
This replaces a bug in the first patch which was incorrectly relying only
on non-zero depth (not sure how that had no failures). (Ilia)

Cc: Chris Forbes <chrisf at ijw.co.nz>
Reported-by: Mark Janes <mark.a.janes at intel.com> (Jenkins)
References: https://www.opengl.org/registry/specs/ARB/texture_view.txt
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92609
Signed-off-by: Ben Widawsky <benjamin.widawsky at intel.com>
---
 src/mesa/drivers/dri/i965/gen8_surface_state.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/gen8_surface_state.c b/src/mesa/drivers/dri/i965/gen8_surface_state.c
index 18b8665..ba97df8 100644
--- a/src/mesa/drivers/dri/i965/gen8_surface_state.c
+++ b/src/mesa/drivers/dri/i965/gen8_surface_state.c
@@ -252,7 +252,7 @@ gen8_emit_texture_surface_state(struct brw_context *brw,
         format == BRW_SURFACEFORMAT_BC7_UNORM))
       surf[0] |= GEN8_SURFACE_SAMPLER_L2_BYPASS_DISABLE;
 
-   if (_mesa_is_array_texture(target) || target == GL_TEXTURE_CUBE_MAP)
+   if (_mesa_is_array_texture(mt->target) || mt->target == GL_TEXTURE_CUBE_MAP)
       surf[0] |= GEN8_SURFACE_IS_ARRAY;
 
    surf[1] = SET_FIELD(mocs_wb, GEN8_SURFACE_MOCS) | mt->qpitch >> 2;
@@ -436,7 +436,7 @@ gen8_update_renderbuffer_surface(struct brw_context *brw,
       /* fallthrough */
    default:
       surf_type = translate_tex_target(gl_target);
-      is_array = _mesa_tex_target_is_array(gl_target);
+      is_array = _mesa_tex_target_is_array(mt->target);
       break;
    }
 
-- 
2.6.1