[Mesa-dev] [PATCH 2/2] i965: Implement compute sampler state atom.

[Ben Widawsky]

On Mon, Jan 18, 2016 at 12:37:18PM -0800, Francisco Jerez wrote:
> Fixes a number of GLES31 CTS failures and hangs on various hardware:
> 
>  ES31-CTS.texture_gather.plain-gather-depth-2d
>  ES31-CTS.texture_gather.plain-gather-depth-2darray
>  ES31-CTS.texture_gather.plain-gather-depth-cube
>  ES31-CTS.texture_gather.offset-gather-depth-2d
>  ES31-CTS.texture_gather.offset-gather-depth-2darray
>  ES31-CTS.layout_binding.sampler2D_layout_binding_texture_ComputeShader
>  ES31-CTS.layout_binding.sampler2DArray_layout_binding_texture_ComputeShader
>  ES31-CTS.explicit_uniform_location.uniform-loc-types-samplers
>  ES31-CTS.compute_shader.resources-texture
> 
> Some of them were actually passing by luck on some generations even
> though we weren't uploading sampler state tables explicitly for the
> compute stage, most likely because they relied on the cached sampler
> state left from previous rendering to be close enough.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92589
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93312
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93325
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93407
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93725
> Reported-by: Marta Lofstedt <marta.lofstedt at intel.com>

Thanks a lot for tracking this down. I was going with Marta's insight of the
DEPTH_32F format thing and getting nowhere. It's really incredible that anything
worked at all.

[snip]

> +
> +static void
> +brw_upload_cs_samplers(struct brw_context *brw)
> +{
> +   /* BRW_NEW_COMPUTE_PROGRAM */
> +   struct gl_program *cs = (struct gl_program *) brw->compute_program;
> +   if (!cs)
> +      return;
> +
> +   brw_upload_sampler_state_table(brw, cs, &brw->cs.base);
> +}
> +

Could you explain how brw->compute_program can be NULL here? I'm just trying to
understand this a bit better...

> +const struct brw_tracked_state brw_cs_samplers = {
> +   .dirty = {
> +      .mesa = _NEW_TEXTURE,
> +      .brw = BRW_NEW_BATCH |
> +             BRW_NEW_COMPUTE_PROGRAM,
> +   },
> +   .emit = brw_upload_cs_samplers,

[snip]