Quick Fix: Brightness Control on Laptop for Linux (Mint, Ubuntu, etc.)

Here's a tip that might help some people out. So I've installed various Linux distributions on my Acer TimelineX (3820T series) and usually find much of the hardware working out of the box without additional tweaks. One thing that I noticed which wasn't always working properly was the brightness toggle via keyboard (Fn + left/right arrows). Turns out editing the GRUB config file did the trick (see below).

Steps are as follows:

  • Open /etc/default/grub with your favorite editor
  • Edit the GRUB_CMDLINE_LINUX="" line to include "acpi_osi=Linux"
  • Save changes and do a "sudo update-grub"
  • Lastly "sudo reboot"
There are different approaches/variations to this fix that I have tested and let me know if this one in particular works for you!