[drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung

["Justin P. Mattock" <justinmattock@gmail.com>]

This is happening both with MAINLINE and NEXT.

basically system is running fine, then under load system becomes really 
sluggish and unresponsive. I was able to get dmesg of the error..:

[ 7745.007008] ath9k 0000:05:00.0 wlan0: disabling VHT as WMM/QoS is not 
supported by the AP
[ 7745.007736] wlan0: associate with 68:7f:74:b8:05:82 (try 1/3)
[ 7745.011456] wlan0: RX AssocResp from 68:7f:74:b8:05:82 (capab=0x411 
status=0 aid=5)
[ 7745.011529] wlan0: associated
[ 8120.812482] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer 
elapsed... GPU hung
[ 8120.812642] [drm] capturing error event; look for more information in 
/debug/dri/0/i915_error_state
[ 8122.328682] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer 
elapsed... GPU hung
[ 8122.328845] [drm:i915_reset] *ERROR* GPU hanging too fast, declaring 
wedged!
[ 8122.328850] [drm:i915_reset] *ERROR* Failed to reset chip.

full log is here: http://fpaste.org/7xH8/

as for good kernels from what I remember 3.6.0-rc1. I can try a bisect 
on this once I get the time. or if anybody has a patch I can test.

Justin P. Mattock