Linux brightness setting reset issue

In debian squeeze, brightness setting of gnome-power-manager will not be used after reboot. After each reboot, the screen will be with full brightness. 

After googling, it seems most of the Linux distribution have this issue. After searching for a good amount of time, found a simple command to change the brightness.  Adding that command invocation at the system startup resolved the issue

Following steps will help us in solving the brightness reset problem

1. Creating shell script file named as "reset-brightness.sh" with the content

#!/bin/sh
echo 0 > /sys/class/backlight/acpi_video0/brightness

    Value after the echo is the brightness value. Change it to your need. To get the maximum allowed value for the brightness, issue the command "cat /sys/class/backlight/acpi_video0/max_brightness"


2. Change the file permission of this file using "chmod +x  reset-brightness.sh"

3. Since this command requires super user permission, we may need to provide the super user password. Since this is not possible in automated invocation, we will add this script to NOPASSWD argument in the /etc/sudoers as below

sam    ALL=(ALL) ALL, NOPASSWD:/home/sam/reset-brightness.sh

4. Add this script to startup application as shown below

  

5. Open gnome-power-manager and make sure you have set the same value as mentioned "step 1" 

(value after echo). In this example its '0'. Show drag slider to the left end as shown

After doing all these steps, the brightness settings will be respected even after reboot or suspend

Once the brightness setting issue is fixed in Linux  distribution or kernel, we can remove the script from startup