https://bugs.freedesktop.org/show_bug.cgi?id=26891
--- Comment #27 from Alex Deucher agd5f@yahoo.com 2012-08-03 19:23:34 UTC --- (In reply to comment #26)
Created attachment 65100 [details] [review] hacked-up radeon VFCT BIOS access patch
So the good news is that a VFCT ACPI table does indeed show up when I boot under UEFI native mode on the HP EliteBook.
I hacked up some code to get the BIOS from there and it successfully brought up the card and drove my DisplayPort screen. (hack patch attached)
Excellent.
The bad news is that the LVDS panel first went backlight-off, on starting X started displaying flickering pixelgarbage and at some later point the entire box locked up.
You probably need this patch: http://lists.freedesktop.org/archives/dri-devel/2012-July/025567.html