How to fix the Brightness problem in ubuntu 14.4?

It is very simple follows these steps

1. 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

2. 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

3. 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.

4. Log out and log in back.

The brightness control should be working through function keys now.

Hope this helps 🙂 .