Brightness issues are some of the most common I ever found in Ubuntu. Either laptop brightness function keys don't work or brightness is reset to max at every boot. In case you are experiencing issues too,following are a few solutions I made for myself:
For the devices using acpi_video0 interface:
As tested on Dell Vostro 3360 (that uses acpi_video0 interface), the brightness can be changed by Function Keys, but is reset to full at every boot of Ubuntu. Follow these instructions:
Add the following bold line at the indicated place to /etc/rc.local (this can be done by running "sudo nano /etc/rc.local")
Download the binaries from here:
chmod 666 /sys/class/backlight/acpi_video0/brightness
After that, extract and copy all the files in the folder named "service" to a new folder named “.brightn” placed in your home folder and add a refrence in startup to it with the command as the full path to the executable file. You may need to fix permissions for the file (Right click, click on Permissions and allow the file to be run as executable)
The startup command must run as follows:
For the devices using intel_backlight interface:
For devices that need intel_backlight, follow the same steps above, just replace "acpi_video0" in the rc.local step with "intel_backlight". Also, use these binaries instead:
Then follow the same steps, copying all files from "intelServ" instead.
For the devices using setpci interface:
This is probably for devices where Function keys do not work and hence, there is no way to change the brightness (tested on Xubuntu 13.04 on Asus Eee PC 1015 CX). Extract the following binaries to the ".brightn" folder and add a startup refrence to the file named "start":
You also need a visudo exception to be added. This means that if you want to run a sudo command without password, run "sudo visudo" in terminal and add the bold line at the position indicated.
Replace YOURGROUP by your group name.
%sudo ALL=(ALL:ALL) ALL
%YOURGROUP ALL=(ALL:ALL) NOPASSWD:/usr/bin/setpci
Now you can adjust (and save) the brightness by running "./.bright/adjust" in terminal or by running the "adjust" file.
My orignal thread is here: http://ubuntuforums.org/showthread.php?t=2018560
Please report any broken links.
Note: The attached source files are Real Studio Projects since I develop in real studio (now Xojo).