[Mesa-dev] SandyBridge issue likely related to fast color clears using meta operations

[Samuel Iglesias Gonsálvez]

On 2014-09-02 18:58, Emil Velikov wrote:
> Hi Samuel,
> 
> On 02/09/14 17:22, Samuel Iglesias Gonsálvez wrote:
>> Adding Kristian in Cc.
>> 
>> Sam
>> 
>> On Tue, 2014-09-02 at 18:16 +0200, Samuel Iglesias Gonsálvez wrote:
>>> Hello,
>>> 
>>> Two weeks ago, Iago and myself sent a batch of patches that added
>>> geometry shader support for SandyBridge [0].
>>> 
>>> Recently, we rebased our patches against master [1] and found
>>> that some things are not working properly any more. Particularly, we
>>> have plenty of cases where we only get a black screen when using a
>>> geometry shader, and in these cases it seems as if some outputs of 
>>> the
>>> geometry shader got "lost" by the time they become inputs in the
>>> fragment shader (some input varyings in the fragment shader that come
>>> from the outputs of the geometry seem to be zeroed). The values we
>>> output in the geometry shader are correct though, since they are
>>> correctly captured by transform feedback.
>>> 
>>> A bisect shows that the commit that introduced this problem is
>>> 2f28a0dc231 i965: Implement fast color clears using meta operations 
>>> [2].
>>> 
> Seemingly the commit caused some issues which should be fixed with the
> following. AFAICS the patch has landed in master, but I'm not sure if 
> your
> work is based on top of it or not.
> 
> http://lists.freedesktop.org/archives/mesa-dev/2014-August/066917.html
> 

Yes, we rebased the patches on top of today's master (5a4e0f3) which 
also has the commit you mention.

Sam