https://bugs.freedesktop.org/show_bug.cgi?id=28474
--- Comment #6 from Marek Olšák maraeo@gmail.com 2010-06-26 16:20:21 PDT --- 1) Does r300c lock up too?
2) Set these environment variables:
RADEON_NO_TCL=1 RADEON_DEBUG=notiling,noimmd,fakeocc
and please let me know whether it helps or not.