* Kernel 3.7.7
* mesa from git (git-34dc4d6) on AMD BARTS
* libdrm 2.4.42

Psychonauts locks the GPU in the intro, filling kernel log with:
févr. 16 15:45:13 archMain kernel: radeon 0000:01:00.0: GPU lockup CP stall for
more than 10000msec
févr. 16 15:45:13 archMain systemd-journal[206]: Forwarding to syslog missed 2
messages.
févr. 16 15:45:13 archMain kernel: radeon 0000:01:00.0: GPU lockup (waiting for
0x0000000000007bc4 last fence id 0x0000000000007ba4)
févr. 16 15:45:13 archMain kernel: radeon 0000:01:00.0: couldn't schedule ib
févr. 16 15:45:13 archMain kernel: [drm:radeon_cs_ib_chunk] *ERROR* Failed to
schedule IB !
févr. 16 15:45:13 archMain kernel: radeon 0000:01:00.0: couldn't schedule ib
févr. 16 15:45:13 archMain kernel: [drm:radeon_cs_ib_chunk] *ERROR* Failed to
schedule IB !

Apitrace can reproduce the lockup on my computer:
http://pkgbuild.com/~lcarlier/traces/Psychonauts.trace.tar.gz