https://bugs.freedesktop.org/show_bug.cgi?id=38675
--- Comment #1 from Alex Deucher agd5f@yahoo.com 2011-06-25 12:30:52 PDT --- This might be a duplicate of bug 38583. Relevant patches: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdif... http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdif...
If they don't help, can you bisect?