On 01/28/2016 02:29 PM, Topi Pohjolainen wrote:
> Validation may kick off copies and subsequently color resolves.
> Color resolves (and the copies themselves if ending up in meta path)
> will overwrite the internal driver state but are not prepared to
> restore it. Instead of adding that capability the validation can be
> simply performed before the state is updated.
The problem isn't src/mesa/drivers/common/meta*. The problem is
brw_meta_* because it directly pokes at driver context state instead of
using higher-level operations, right?
Do we have a test case that encounters this problem? It seems like this
must have been very difficult to detect, and that worries me. It's
completely non-obvious that brw_validate_textures will do meta ops. I
wonder if we could add some sort of flag in debug builds to signal
"doing meta would be bad right now."
Either way, this patch is
Reviewed-by: Ian Romanick
After it gets a bit of extra soak time on master, we may want to
nominate it for stable. This clearly fixes a problem, and I don't want
to have to debug an application rendering error that could result from
it. :)
> Signed-off-by: Topi Pohjolainen
> ---
> src/mesa/drivers/dri/i965/brw_draw.c | 18 +-
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_draw.c
> b/src/mesa/drivers/dri/i965/brw_draw.c
> index 8737c64..c295d91 100644
> --- a/src/mesa/drivers/dri/i965/brw_draw.c
> +++ b/src/mesa/drivers/dri/i965/brw_draw.c
> @@ -420,6 +420,15 @@ brw_try_draw_prims(struct gl_context *ctx,
> if (ctx->NewState)
>_mesa_update_state(ctx);
>
> + /* We have to validate the textures *before* checking for fallbacks;
> +* otherwise, the software fallback won't be able to rely on the
> +* texture state, the firstLevel and lastLevel fields won't be
> +* set in the intel texture object (they'll both be 0), and the
> +* software fallback will segfault if it attempts to access any
> +* texture level other than level 0.
> +*/
> + brw_validate_textures(brw);
> +
> /* Find the highest sampler unit used by each shader program. A bit-count
> * won't work since ARB programs use the texture unit number as the
> sampler
> * index.
> @@ -435,15 +444,6 @@ brw_try_draw_prims(struct gl_context *ctx,
> brw->vs.base.sampler_count =
>_mesa_fls(ctx->VertexProgram._Current->Base.SamplersUsed);
>
> - /* We have to validate the textures *before* checking for fallbacks;
> -* otherwise, the software fallback won't be able to rely on the
> -* texture state, the firstLevel and lastLevel fields won't be
> -* set in the intel texture object (they'll both be 0), and the
> -* software fallback will segfault if it attempts to access any
> -* texture level other than level 0.
> -*/
> - brw_validate_textures(brw);
> -
> intel_prepare_render(brw);
>
> /* This workaround has to happen outside of brw_upload_render_state()
>
___
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
