Ubuntu 14.04 brightness control issue with Intel card

Recently noticed an issue in Dell laptop,It was pre installed with ubuntu 12ish version. Once this was upgraded to ubuntu 14.04 LTS version I noticed there is issue with backlight display and it was not working. Below soultion worked for me hence thought to be useful for others and I am posting here... Steps

[1] Check /usr/share/X11/xorg.conf.d directory and find out if you see file named as “20-intel.conf”

oyeweb@oyeweb-Latitude-3540:~$ ls -ltr /usr/share/X11/xorg.conf.d

total 36

-rw-r--r-- 1 root root 842 Feb 5 2014 50-wacom.conf

-rw-r--r-- 1 root root 364 Feb 5 2014 11-evdev-trackpoint.conf

-rw-r--r-- 1 root root 590 Feb 5 2014 11-evdev-quirks.conf

-rw-r--r-- 1 root root 115 Feb 5 2014 50-vmmouse.conf

-rw-r--r-- 1 root root 590 Apr 10 2014 51-synaptics-quirks.conf

-rw-r--r-- 1 root root 1757 Apr 10 2014 50-synaptics.conf

-rw-r--r-- 1 root root 1867 Dec 10 23:47 10-quirks.conf

-rw-r--r-- 1 root root 1099 Dec 10 23:47 10-evdev.conf

[2] If you don't see “20-intel.conf” upi will have to create a file for the same. You can do this as a super user hence follow the command




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

[3] Now please edit the file by using vi or any other command

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

you will have to add following things into your file

Section
"Device"

    
   Identifier  "card0"

    
   Driver      "intel"

    
   Option      "Backlight"  "intel_backlight"

    
   BusID       "PCI:0:2:0"

EndSection

Please save by using :wq! and restart your laptop/pc. 

I have not remembered if restarts is required but anyhow this solution will work.

Please comment if you see further issues. We will be happy to help.