Can't adjust screen brightness on Macbook Pro 10,1 Ubuntu 13.10

Solution 1:

I installed Ubuntu 13.10 on my 15" MacBook Pro 11,3 (Late 2013) with kernel 3.14.0-031400rc5-generic and the 331.49 Nvidia driver. My brightness control keys were not working either. Fix was to add this line to /etc/rc.local:

setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0

Brightness control keys work now.

Solution 2:

if you want to use the backlight with the nvidia drivers, try running (as root):

setpci -v -H1 -s 00:01.00 BRIDGE_CONTROL=0

Then adjust the backlight using the gmux_backlight sysfs file:

echo 200 > /sys/class/backlight/gmux_backlight/brightness
echo 800 > /sys/class/backlight/gmux_backlight/brightness

Solution 3:

Find video/graphics card in Ubuntu and Linux Mint

Run the command below in terminal to know what video card is used for the backlight/brightness:

ls /sys/class/backlight/

find graphics driver in Ubuntu

As you can see, the output for me is dell_backlight and intel_backlight. An indicator that the graphics card in use is Intel. Another way to find out the graphics card would be to go in System Settings->Details->Graphics. You can see the graphic card in use.

If your graphics card is Intel, you can proceed with the fix below. Fix brightness control issue with Intel card in Ubuntu and Linux Mint:

Open a terminal and create the following configuration file, if it does not exist:

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

Now we need to edit this file. You can use any editor be it a terminal one or graphical.

sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf

Add the following lines to this file:

Section "Device"
        Identifier  "card0"
        Driver      "intel"
        Option      "Backlight"  "intel_backlight"
        BusID       "PCI:0:2:0"

EndSection

Save it. Log out and log in back. The brightness control should be working through function keys now:

Fix brightness control not working in Ubuntu 13.10