[Mesa-dev] [PATCH] egl/x11/dri3: do not expose the preserved swap behavior (to be squashed)

[Martin Peres]

On 19/11/15 14:06, Martin Graesslin wrote:
> On Thursday, November 19, 2015 1:54:22 PM CET Martin Peres wrote:
>> On 11/11/15 00:44, Eric Anholt wrote:
>>> Martin Peres <martin.peres at linux.intel.com> writes:
>>>> The preserved swap behavior is currently untested in piglit and not
>>>> supported on the GLX side. Before working on implementing it for
>>>> EGL/DRI3, let's disable it until support comes.
>>>>
>>>> This patch is trivial enough and will likely be squashed in the commit
>>>> egl/x11: Implement dri3 support with loader's dri3 helper
>>>>
>>>> Signed-off-by: Martin Peres <martin.peres at linux.intel.com>
>>> This looks good to me.  I don't think anybody really cares about
>>> SWAP_BEHAVIOR_PRESERVED -- the buffer_age stuff was what you really
>>> wanted all along.
>> Hey Eric and Martin,
>>
>> It seems like KWin is relying on SWAP_BEHAVIOR_PRESERVED for its EGL
>> backend. Should we add proper support for it in mesa or should we
>> propose a patch for kwin to test for the extension to be present before
>> using it?
>>
>> Martin, what is your opinion on this since buffer age is what you need
>> and you already have support for it for the glx and wayland backends?
> That's certainly a left over from before buffer age.  I don't know whether we
> can remove it unconditionally. Not every GLES harware which does support X11
> supports buffer age.
>
> I assume the smartest thing to do is not ask for PRESERVED if buffer age is
> supported.

Sounds good! Checking for the availability of both buffer age and 
preserved, preferring buffer age but not forcing behaviour preserved if 
buffer age is missing (only enable it if the extension exists).

Thanks for your quick answer Martin G.
Martin P.