https://bugs.freedesktop.org/show_bug.cgi?id=45018
--- Comment #24 from Jerome Glisse glisse@freedesktop.org 2012-02-21 09:44:50 PST --- I pushed a mesa fix for bo allocation issue. If you enable 2d tiling properly you shouldn't have lockup anymore. There is also a kernel patch to fix kernel issue after gpu lockup.
http://lists.freedesktop.org/archives/dri-devel/2012-February/019293.html
To properly enabled 2d tiling you need libdrm from git and ddx from git and add:
Option "ColorTiling2D" "true"
To your gpu device section of xorg configuration