Comment 34 for bug 347569

Irom: Hmmm... It sounds to me like you are experiencing another issue entirely. I'm afraid yours might not be resolved until the Radeon-Rewrite code comes into action. What happens if you use the links above regarding radeon-rewrite and the new radeon drivers? You will have to undo those changes if you want other OpenGL apps to still run without freezing your system, but if that solves your problem for glxgears and desktop effects then you may need to wait for those drivers. Unless we can pull a patch from upstream. I think this is the link:
https://launchpad.net/~xorg-edgers/+archive/radeon

If you try this mesa and follow the directions on the page for the radeon drivers too, to see if that fixes it. Then undo the mesa install and see if maybe just the drivers alone may fix the issue. Please report your findings.