[Mesa-dev] [PATCH] st/mesa: check shader image format support before using PBO download

[Samuel Pitoiset]

This fixes the following piglits on nvc0 (tested on GK106, and should 
work like a charm on Fermi as well):

- spec/mesa_pack_invert/mesa_pack_invert-readpixels/PBO unorm BGRA
- spec/arb_pixel_buffer_object/fbo-pbo-readpixels-small
- spec/arb_pixel_buffer_object/pbo-read-argb8888
- spec/arb_pixel_buffer_object/pbo-readpixels-small

Tested-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>

On 06/06/2016 12:59 AM, Ilia Mirkin wrote:
> ARB_shader_image_load_store only requires a very fixed list of formats
> to be supported, while textures may be in all kinds of formats, like
> BGRA which are presently not supported on at least Kepler.
>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  src/mesa/state_tracker/st_cb_readpixels.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/src/mesa/state_tracker/st_cb_readpixels.c b/src/mesa/state_tracker/st_cb_readpixels.c
> index 6df3a39..09450c9 100644
> --- a/src/mesa/state_tracker/st_cb_readpixels.c
> +++ b/src/mesa/state_tracker/st_cb_readpixels.c
> @@ -79,6 +79,7 @@ try_pbo_readpixels(struct st_context *st, struct st_renderbuffer *strb,
>                     const struct gl_pixelstore_attrib *pack, void *pixels)
>  {
>     struct pipe_context *pipe = st->pipe;
> +   struct pipe_screen *screen = pipe->screen;
>     struct cso_context *cso = st->cso_context;
>     struct pipe_surface *surface = strb->surface;
>     struct pipe_resource *texture = strb->texture;
> @@ -91,6 +92,11 @@ try_pbo_readpixels(struct st_context *st, struct st_renderbuffer *strb,
>     if (texture->nr_samples > 1)
>        return false;
>
> +   if (!screen->is_format_supported(screen, dst_format, PIPE_TEXTURE_2D,
> +                                    texture->nr_samples,
> +                                    PIPE_BIND_SHADER_IMAGE))
> +      return false;
> +
>     desc = util_format_description(dst_format);
>
>     /* Compute PBO addresses */
>

-- 
-Samuel