Comment # 2 on bug 66932 from Alex Deucher

(In reply to comment #0)
> 
> I did a bisect and found that this commit introduced the corruption:
> 
> http://cgit.freedesktop.org/~agd5f/linux/commit/?h=drm-fixes-3.
> 11&id=7ad8d0687bb5030c3328bc7229a3183ce179ab25

Prior to that commit, the driver didn't actually change clock levels.

Does it work any better if you build radeon as a module rather than building it
into the kernel?