Ubuntu 12.04 LTS - a workaround to save brightness

ubuntu_save_brightness.md

####Issue :

My Dell OptiPlex 3030 Unbuntu machine cannot save brightness, it goes to maximum brightness every time I save to lower brightness and reboot. It looks like related to Ubuntu. I found out a solution for it.

####Workaround :

1. Modify grub file

   In terminal, type command to open grub file

   sudo gedit /etc/default/grub

   then change GRUB_CMDLINE_LINUX to

   GRUB_CMDLINE_LINUX="acpi_backlight=vendor"

   save the changes, then type

   sudo update-grub

   to reflect the changes

2. Get brightness value

   Adjust brightness for machine, type command in terminal and then check the value

   sudo gedit /sys/class/backlight/intel_backlight/brightness

   it is 1917 in my machine

3. Setup sudo with no-password

   Type command to open sudoers file

   sudo gedit /etc/sudoers

   then change %sudo ALL=(ALL:ALL) ALL to

   %sudo ALL=NOPASSWD: ALL

   save the changes

4. Modify profile file

   Type command to open profile file

   sudo gedit /etc/profile

   at the end of file, add below lines

   sudo -S sh -c 'echo 1917 > /sys/class/backlight/intel_backlight/brightness'

   save the changes and reboot the machine to verify the result