Comment 14 for bug 952486

Hey,

I did a bisection on my lenovo W500 (almost same hardware as T500) and it turns out that the bug was introduced in 2.6.37-2.9 natty kernel, and made it's way back to maverick with 2.6.38-10.44 update. After that I bisected a vanilla kernel, and it turns out that the offending commit is: [ba032a58d1f320039e7850fb6e8651695c1aa571] drm/radeon/kms: rework spread spectrum handling
so it is a bug with spread spectrum handling on displayport. This feature was disabled on DP and HDMI prior to that commit.

It seems that this is already reported to radeon/kernel guys here:
https://bugs.freedesktop.org/show_bug.cgi?id=40699
I'm gonna provide more details there.