[Mesa-dev] [PATCH] egl: dri2: Use present extension. (Was: Re: [RFC] egl: Add DRI3 support to the EGL backend.)

[Michel Dänzer]

On 06.11.2014 19:18, Joonas Lahtinen wrote:
> On to, 2014-11-06 at 18:12 +0900, Michel Dänzer wrote:
>> On 05.11.2014 20:14, Joonas Lahtinen wrote:
>>>
>>> Modified not refer to DRI3, just uses the present extension to get rid
>>> of the excess buffer invalidations.
>>
>> AFAICT there's no fallback from your changes to the current behaviour if
>> the X server doesn't support the Present extension. There probably needs
>> to be such a fallback.
>
> It gets rid of such nasty hack (the intel_viewport one), that I thought
> there is no point making fallback. Because without this, the egl dri2
> backend is fundamentally broken anyway.

Well, AFAICT your code uses Present extension functionality 
unconditionally, without checking that the X server supports Present. I 
can't see how that could possibly work on an X server which doesn't 
support Present, but I think it would be better to keep it working at 
least as badly as it does now in that case. :)


-- 
Earthling Michel Dänzer            |                  http://www.amd.com
Libre software enthusiast          |                Mesa and X developer