Linux Mint 17/ Ubuntu 14 brightness auto adjust

Edit 29.05.2017:
You can use xbacklight app to set the brightness for you. You can then add it to the StartupApps.
Just install it: sudo apt-get install xbacklight
And then run: xbacklight -set 70 where 70 is the percent for the brightness.

I tried several things to auto adjust my brightness settings and stop changing it every time the PC is rebooted. So this is the only way it worked:

  1. sudo gedit /etc/rc.local
  2. cat /sys/class/backlight/acpi_video0/max_brightness
  3. the command will show you what is the maximum level of brightness you have
  4. echo xx > /sys/class/backlight/acpi_video0/brightness #Add this line in the rc.local file above the “exit 0” statement. xx is a number of the brightness you have.
  5. Save and reboot and no more brightness adjusting 🙂

Answer taken from here:

For the 3.16 kernel I had also to edit the grub to include the native backlight so the rc.local config would work:

sudo nano /etc/default/grub

change line


GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"

You may also like...