[Mesa-dev] [PATCH] st/mesa: only resolve is number of samples is > 1

[Christoph Bumiller]

On 11/30/2011 09:10 PM, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
> 
> This fixes the firefox crash but I've no idea if its correct.

I don't think it is.
Visual.samples is the value passed to RenderbufferStorageMultisample,
and 1 here means "a desired minimum number of samples" so the actual
sample count may (even if very unlikely) be > 1.

If you don't implement resource_resolve, mesa/st shouldn't expose
framebuffer_multisample for you, or you shouldn't expose > 0 samples
(that's an issue with the gallium interface, which doesn't define
whether 0 means "no storage" or "single sampled").

> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>
> ---
>  src/mesa/state_tracker/st_cb_blit.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/src/mesa/state_tracker/st_cb_blit.c b/src/mesa/state_tracker/st_cb_blit.c
> index 750f541..8f0c2e8 100644
> --- a/src/mesa/state_tracker/st_cb_blit.c
> +++ b/src/mesa/state_tracker/st_cb_blit.c
> @@ -178,7 +178,7 @@ st_BlitFramebuffer(struct gl_context *ctx,
>        st->pipe->render_condition(st->pipe, NULL, 0);
>     }
>  
> -   if (readFB->Visual.sampleBuffers > drawFB->Visual.sampleBuffers) {
> +   if (readFB->Visual.sampleBuffers > drawFB->Visual.sampleBuffers && readFB->Visual.samples > 1) {
>        struct pipe_resolve_info info;
>  
>        if (dstX0 < dstX1) {