Intel i915GM (xf86-video-intel modesetting) Tearing duringplayback with XV

[will]

> >  it appears
> > there is nothing in the XV code that would synchronise to the vertical
> > blanking period for display (overlay?) updates?
> 
> Right, the textured video adaptor doesn't delay for vsync; that's
> because we don't have the infrastructure in place to do this without
> spinning inside the driver, which wastes a lot of CPU time.

Thanks for confirming this. I certainly had issues with CPU spinning when
using double buffering (in the previous i810 driver) it would often end up
eating all the CPU time. In the end I hacked the xine video out loop and put
in a glx wait which seemed to fix things.

> 
> > Any suggestions?
> 
> You can still use the overlay video adaptor, which does sync with
> vretrace.

Do I need to modify the code for this?

> 
> --
> keith.packard at intel.com