[Mesa-dev] [PATCH 1/5] glx/dri3: Fix glXWaitForSbcOML() to handle targetSBC==0 correctly.

[Axel Davy]

On 02/12/2014 20:53, Mario Kleiner wrote :
> targetSBC == 0 is a special case, which asks the function
> to block until all pending OpenGL bufferswap requests have
> completed.
>
> Currently the function just falls through for targetSBC == 0,
> returning bogus results.
>
> This breaks applications originally written and tested against
> DRI2 which also rely on this not regressing under DRI3/Present,
> e.g., Neuro-Science software like Psychtoolbox-3.
>
> This patch fixes the problem.
>
> Cc: "10.3 10.4" <mesa-stable at lists.freedesktop.org>
> Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
> ---
>   src/glx/dri3_glx.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
> index a9ff73b..b4ac278 100644
> --- a/src/glx/dri3_glx.c
> +++ b/src/glx/dri3_glx.c
> @@ -529,7 +529,8 @@ dri3_wait_for_sbc(__GLXDRIdrawable *pdraw, int64_t target_sbc, int64_t *ust,
>   {
>      struct dri3_drawable *priv = (struct dri3_drawable *) pdraw;
>   
> -   while (priv->recv_sbc < target_sbc) {
> +   while ((target_sbc != 0 && priv->recv_sbc < target_sbc) ||
> +          (target_sbc == 0 && priv->recv_sbc < priv->send_sbc)) {
>         if (!dri3_wait_for_event(pdraw))
>            return 0;
>      }
Looks good to me.

Reviewed-by: Axel Davy <axel.davy at ens.fr>