https://bugs.freedesktop.org/show_bug.cgi?id=41569
--- Comment #10 from Alex Deucher agd5f@yahoo.com 2012-01-10 12:51:52 PST --- (In reply to comment #9)
These patches may fix some systems, but they also cause a similar problem on my HP ProBook 6465b (A6-3410MX processor with built-in GPU). There is also someone else with the same issue on different ProBook model: http://forums.gentoo.org/viewtopic-t-908460.html Reverting the patch from comment #6 fixes it at least for me.
Please attach your xorg log and dmesg output.