xf86-video-ati page flipping fixes

[Ville Syrjälä]

On Thu, May 05, 2011 at 09:54:48AM -0700, Jesse Barnes wrote:
> On Thu, 5 May 2011 18:33:11 +0200
> Mario Kleiner <mario.kleiner at tuebingen.mpg.de> wrote:
> 
> > Are you sure this is also the case even when kms page flipping is  
> > used for fullscreen drawables?
> > 
> > The workaround i implemented in my toolkit for the page flipping  
> > problem when using fullscreen drawables on current x servers was to  
> > make sure that it always ends a session with an even number of  
> > completed page-flipping swaps, by checking 'sbc' and issuing an extra  
> > swap before closing its window if the sbc wasn't an even number. This  
> > makes sure that the same buffer objects are assigned as front- and  
> > backbuffer at the time the window closes as when the application  
> > started and opened its fullscreen window. This fixed any desktop  
> > corruption i'd usually get when running compiz with non-redirected  
> > fullscreen windows after quitting my application.
> > 
> > I could be totally wrong, but at least the symptoms and the working  
> > workaround suggested fullscreen drawables do share their back buffers  
> > when page flipping is on.
> 
> Is this workaround needed on the Intel driver too?  Or is this just a
> driver bo name tracking bug?

I don't have Intel hw for testing, but as the code looks to be simply
copy-pasted from one driver to the other, I'd say it needs the same
fixes.

-- 
Ville Syrjälä
syrjala at sci.fi
http://www.sci.fi/~syrjala/