Comment 24 for bug 1079440

I see a very similar problem on a Thinkpad T400. Using the laptop panel everything is fine, but plugging in a monitor eventually leads to a very hard hang. The monitor's resolution is correctly detected in my case, and the GPU is indentified as "Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) (prog-if 00 [VGA controller])".

I can hit the problem within 5 minutes using AccelMethod SNA; using UXA can give me several hours on average, but eventually it too dies. In both cases:

cat /sys/kernel/debug/dri/0/i915_error_state
no error state collected

I did grab a register dump after it died using SNA, if that's of any help.