Comment 27 for bug 946899

Just to give an idea of the frequency of the GPU hangs, I pasted below a part from my syslog. After the 3rd hang in a row, the system became unresponsive and I had to do an emergency shut-down (Alt+SysRq, R, E, I, S, U , B). Hope this will help with the troubleshooting.

Mar 11 21:45:03 sppc26 kernel: [ 0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz-3.5.0-26-generic root=UUID=5083e04c-1bad-44bf-a241-c839914a697a ro crashkernel=384M-2G:64M,2G-:128M quiet splash i915.i915_enable_rc6=0
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Mar 11 21:47:07 sppc26 kernel: [ 159.875052] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Mar 11 21:47:07 sppc26 kernel: [ 159.875056] [drm] capturing error event; look for more information in /debug/dri/0/i915_error_state
Mar 11 21:47:07 sppc26 kernel: [ 159.878208] [drm] Enabling RC6 states: RC6 off, RC6p off, RC6pp off
Mar 11 21:47:20 sppc26 kernel: [ 172.694397] CPU2: Package power limit notification (total events = 1)
Mar 11 21:47:20 sppc26 kernel: [ 172.694399] CPU3: Package power limit notification (total events = 1)
Mar 11 21:47:20 sppc26 kernel: [ 172.694400] CPU1: Package power limit notification (total events = 1)
Mar 11 21:47:20 sppc26 kernel: [ 172.694401] CPU0: Package power limit notification (total events = 1)
Mar 11 21:47:20 sppc26 kernel: [ 172.705373] CPU3: Package power limit normal
Mar 11 21:47:20 sppc26 kernel: [ 172.705374] CPU1: Package power limit normal
Mar 11 21:47:20 sppc26 kernel: [ 172.705393] CPU2: Package power limit normal
Mar 11 21:47:20 sppc26 kernel: [ 172.705394] CPU0: Package power limit normal
Mar 11 21:57:19 sppc26 kernel: [ 770.979630] CPU1: Package power limit notification (total events = 1068)
Mar 11 21:57:19 sppc26 kernel: [ 770.979633] CPU3: Package power limit notification (total events = 1068)
Mar 11 21:57:19 sppc26 kernel: [ 770.979635] CPU2: Package power limit notification (total events = 1068)
Mar 11 21:57:19 sppc26 kernel: [ 770.979637] CPU0: Package power limit notification (total events = 1068)
Mar 11 21:57:19 sppc26 kernel: [ 770.990639] CPU1: Package power limit normal
Mar 11 21:57:19 sppc26 kernel: [ 770.990641] CPU2: Package power limit normal
Mar 11 21:57:19 sppc26 kernel: [ 770.990642] CPU3: Package power limit normal
Mar 11 21:57:19 sppc26 kernel: [ 770.990643] CPU0: Package power limit normal
Mar 11 21:58:51 sppc26 kernel: [ 863.575435] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Mar 11 21:58:51 sppc26 kernel: [ 863.575750] [drm] Enabling RC6 states: RC6 off, RC6p off, RC6pp off
Mar 11 22:05:38 sppc26 kernel: [ 1270.493341] CPU2: Package power limit notification (total events = 1578)
Mar 11 22:05:38 sppc26 kernel: [ 1270.493344] CPU1: Package power limit notification (total events = 1578)
Mar 11 22:05:38 sppc26 kernel: [ 1270.493346] CPU3: Package power limit notification (total events = 1578)
Mar 11 22:05:38 sppc26 kernel: [ 1270.493347] CPU0: Package power limit notification (total events = 1578)
Mar 11 22:05:38 sppc26 kernel: [ 1270.504379] CPU2: Package power limit normal
Mar 11 22:05:38 sppc26 kernel: [ 1270.504380] CPU0: Package power limit normal
Mar 11 22:05:38 sppc26 kernel: [ 1270.504399] CPU1: Package power limit normal
Mar 11 22:05:38 sppc26 kernel: [ 1270.504400] CPU3: Package power limit normal
Mar 11 22:09:56 sppc26 kernel: [ 1527.956133] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Mar 11 22:12:00 sppc26 kernel: [ 1651.830636] SysRq : This sysrq operation is disabled.
Mar 11 22:12:01 sppc26 kernel: [ 1653.365819] SysRq : This sysrq operation is disabled.
Mar 11 22:12:03 sppc26 kernel: [ 1654.552128] SysRq : This sysrq operation is disabled.
Mar 11 22:12:04 sppc26 kernel: [ 1655.658691] SysRq : Emergency Sync