Installation

You need to have the kernel headers (e.g. linux-header-generic) installed for the kernel you're compiling for. You also need the build tools (build-essential or similar).

git clone git://github.com/patjak/mba6x_bl
cd mba6x_bl
make
sudo make install
sudo depmod -a

Note: You no longer need to specify mba6x_bl as your backlight device in /etc/X11/xorg.conf. This is now handled automatically by promoting the driver above the ACPI backlight interface.

At this point you can load the module

sudo modprobe mba6x_bl

Then restart X (usually log in / log out will do the trick). The module should automatically load on next boot on any MacBook Air 6,x.

If brightness control still doesn't work:

You may need to follow the directions suggested in #65 and do the following:

Create usr/share/X11/xorg.conf.d/98-mba6bl.conf.
In that file, enter the following content (from here):

Section "Device"
  Identifier "Intel Graphics"
  Driver "Intel"
  Option "Backlight"  "mba6x_backlight"
EndSection

Remove /usr/share/X11/xorg.conf.d/20-intel.conf or move it to a backup directory.
Log in/log out or $ reboot.

Debian dkms package

You can either follow the long route https://wiki.kubuntu.org/Kernel/Dev/DKMSPackaging, or download a pre-made .deb.zip file of v1.1.0 from https://github.com/patjak/mba6x_bl/files/505288/mba6xbl-dkms_1.1.0_all.deb.zip, which can be installed with dpkg -i. (Installing v1.0.0 can result in build errors; see #55.)

Ubuntu specific instructions

https://help.ubuntu.com/community/MacBookAir6-2/Trusty#Backlight

Arch Linux dkms package

An Arch Linux prepared package can be found at https://aur.archlinux.org/packages/mba6x_bl-dkms/

Gentoo ebuild

A Gentoo ebuild can be had at https://github.com/chrisperelstein/gentoo-overlay/blob/master/x11-drivers/mba6x_bl/mba6x_bl-9999.ebuild. You can install with layman -o https://github.com/chrisperelstein/gentoo-overlay/raw/master/overlay.xml -a chrisperelstein, unmasking by adding =x11-drivers/mba6x_bl-9999::chrisperelstein ** to /etc/portage/package.accept_keywords, followed by emerge mba6x_bl.