[Mesa-dev] [PATCH] DRI2: Don't disable GLX_INTEL_swap_event unconditionally

[Jesse Barnes]

On Thu, 14 Feb 2013 20:39:36 -0800
Zack Rusin <zackr at vmware.com> wrote:

> GLX_INTEL_swap_event is broken on the server side, where it's
> currently unconditionally enabled. This completely breaks
> systems running on drivers which don't support that extension.
> There's no way to test for its presence on this side, so instead
> of disabling it uncondtionally, just disable it for drivers
> which are known to not support it. It makes sense because
> most drivers do support it right now.
> We'll be able to remove this once Xserver properly advertises
> GLX_INTEL_swap_event.
> 
> Note: This is a candidate for the 9.0 branch.
> 
> Signed-off-by: Zack Rusin <zackr at vmware.com>
> ---
>  src/glx/dri2_glx.c |   15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/src/glx/dri2_glx.c b/src/glx/dri2_glx.c
> index 46a92fd..05808d4 100644
> --- a/src/glx/dri2_glx.c
> +++ b/src/glx/dri2_glx.c
> @@ -1051,7 +1051,8 @@ static const struct glx_context_vtable dri2_context_vtable = {
>  };
>  
>  static void
> -dri2BindExtensions(struct dri2_screen *psc, const __DRIextension **extensions)
> +dri2BindExtensions(struct dri2_screen *psc, const __DRIextension **extensions,
> +                   const char *driverName)
>  {
>     int i;
>  
> @@ -1060,7 +1061,15 @@ dri2BindExtensions(struct dri2_screen *psc, const __DRIextension **extensions)
>     __glXEnableDirectExtension(&psc->base, "GLX_MESA_swap_control");
>     __glXEnableDirectExtension(&psc->base, "GLX_SGI_make_current_read");
>  
> -   if (psc->dri2->base.version >= 4) {
> +   /*
> +    * GLX_INTEL_swap_event is broken on the server side, where it's
> +    * currently unconditionally enabled. This completely breaks
> +    * systems running on drivers which don't support that extension.
> +    * There's no way to test for its presence on this side, so instead
> +    * of disabling it uncondtionally, just disable it for drivers
> +    * which are known to not support it.    
> +    */
> +   if (strcmp(driverName, "vmwgfx") != 0) {
>        __glXEnableDirectExtension(&psc->base, "GLX_INTEL_swap_event");
>     }
>  
> @@ -1204,7 +1213,7 @@ dri2CreateScreen(int screen, struct glx_display * priv)
>     }
>  
>     extensions = psc->core->getExtensions(psc->driScreen);
> -   dri2BindExtensions(psc, extensions);
> +   dri2BindExtensions(psc, extensions, driverName);
>  
>     configs = driConvertConfigs(psc->core, psc->base.configs, driver_configs);
>     visuals = driConvertConfigs(psc->core, psc->base.visuals, driver_configs);

Seems like we should also fix the server to not advertise the extension
if the driver doesn't have the appropriate hooks implemented.  But I
have no problem with doing this on the client side too.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center