[Mesa-dev] [PATCH v3 5/7] radeonsi: Implement DCC fast clear.

[Marek Olšák]

On Fri, Oct 23, 2015 at 12:17 PM, Bas Nieuwenhuizen
<bas at basnieuwenhuizen.nl> wrote:
> On Thu, Oct 22, 2015 at 12:12 PM, Marek Olšák <maraeo at gmail.com> wrote:
>>> diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c
>>> index 5548cba3..a277fa5 100644
>>> --- a/src/gallium/drivers/radeonsi/si_descriptors.c
>>> +++ b/src/gallium/drivers/radeonsi/si_descriptors.c
>>> @@ -234,7 +234,7 @@ static void si_set_sampler_views(struct pipe_context *ctx,
>>>                         } else {
>>>                                 samplers->depth_texture_mask &= ~(1 << slot);
>>>                         }
>>> -                       if (rtex->cmask.size || rtex->fmask.size) {
>>> +                       if (rtex->cmask.size || rtex->fmask.size || rtex->surface.dcc_enabled) {
>>>                                 samplers->compressed_colortex_mask |= 1 << slot;
>>
>> I'd like this flag to be set only when dirty_level_mask is non-zero.
>> Setting this for all textures that have DCC is quite expensive in draw
>> calls.
>
> I think this code is incorrect even without considering DCC. If we do
> a fast clear on a surface which allocates a cmask and then use that
> surface as a texture without calling set_sampler_views in between
> (because it was bound before) we get a stale compressed_colortex_mask.
>
> Some testing shows that this can be triggered using OpenGL, although
> the GL_ARB_texture_barrier extension may be needed to make the result
> not undefined per the specification.

In that case, we should decompress in texture_barrier and not in draw calls.

Marek