[Nouveau] nv_backlight non-functional on MBP 5,3 in EFI mode

[Shea Levy]

Hello,

On my MBP (booted with noaccel=1 due to 
https://bugs.freedesktop.org/show_bug.cgi?id=27501), the nv_backlight 
sysfs knob is non-functional (though modifying nv_backlight/brightness 
does change nv_backlight/actual_brightness). Recently a patch was 
submitted to LKML to create a brightness control for Apple computers 
with a gmux (https://lkml.org/lkml/2012/3/16/388), the created sysfs 
knob does work for me.

Cheers,
Shea Levy