Comment # 16 on bug 79223 from Pierre Ossman

Right now it feels like a lot of the blame falls on xbmc. But at the same time,
this works on nouveau and presumably the proprietary drivers.

I guess the behaviour that xbmc is expecting is that the only time it will wait
for a vblank, is that explicit vblank waiting in step 2.?

Now is that an unreasonable expectation? Or should the radeon driver be fixed
to support this?