https://bugzilla.kernel.org/show_bug.cgi?id=29412
--- Comment #12 from Alex Deucher alexdeucher@gmail.com 2012-03-27 13:41:08 --- Created an attachment (id=72731) --> (https://bugzilla.kernel.org/attachment.cgi?id=72731) alternate fix
After you verify the first patch does not fix the issue, you can try this one. Can you also attach a copy of your vbios? To get a copy of your vbios:
(as root) (use lspci to get the bus id) cd /sys/bus/pci/devices/<pci bus id> echo 1 > rom cat rom > /tmp/vbios.rom echo 0 > rom