Pierre,

I have tested your patch with the 9400M in my macbookpro 5,2. The card boots
correctly with acceleration enabled, and loads GDM. GDM looks completely
correct, but hangs on login with a cursor on a grey screen. It's possible that
LXDE, KDE, or some other DE might work, but gnome-shell never loads. I will try
slim/lxde when I get a chance.

At this point I can switch back to VT where I notice some nouveau errors in
dmesg. Killing GDM (and x11 with it) produces a kernel panic.

Next I booted with the 9600GT with acceleration disabled. The display looks
correct with efifb, but loading nouveau scrambles the VT.

Thank you for your efforts!