Created attachment 108705 [details]
dmesg when lockup occurs

when starting a single player game with planetary annihilation (steam version).
there is a gpu lockup after about 10s (100% reproductible).

I'm able to play with the intel HD4000 and same mesa stack (but it's a bit slow
:p).

system setup :

Archlinux 64bits
mesa 10.3.2
kernel 3.17.1-1-ARCH
radeon HD 7950

tried with and without hyperz, same lockup occurs.

attached dmesg, and glxinfo