Unable to change the brightness on my Dell XPS 15 (L502X)
On my XPS 15, I got it working like this:
- Open
/etc/default/grubwith sudo permissions in your favourite text editor, e.g.sudo gedit /etc/default/grub - Go to the line that starts with
GRUB_CMDLINE_LINUX_DEFAULT, and addacpi_backlight=vendor dell_laptop.backlight=0to whatever is between the quote marks, e.g. my line now looks likeGRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor dell_laptop.backlight=0" - Run
sudo update-grub - Reboot. Your brightness controls should now work.