https://bugzilla.kernel.org/show_bug.cgi?id=33512
--- Comment #4 from Török Edwin edwintorok@gmail.com 2011-08-05 13:58:50 --- (In reply to comment #3)
The only places atombios_crtc_disable() called are from drm_crtc_helper_set_config() and drm_helper_resume_force_mode(). I suspect what is happening is that certain games cause GPU resets which call radeon_gpu_reset() which in turn calls drm_helper_resume_force_mode(). I don't think this is a kernel bug at all. I'd suggest trying a newer mesa if you are using an older version. Try 7.11.
I'm using git master now, and it works far better than 7.10 or 7.11.
Do you see GPU reset messages in your dmesg output after running a problematic game?
I didn't look much at perf output lately, will have to try and see if this is still an issue with latest mesa, and report back.