I am using ubuntu 13.04 and I am unable to change the brightness on my laptop and need a bit a help.
2 Answers
On my XPS 15, I got it working like this:
- Open
/etc/default/grub
with 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=0
to 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.
A temporary workaround is to just set acpi to off in grub (the advice given for the old kernel)" just set acpi=off
like in the older kernels. You lose clean shutdown and battery info, but this is more important for me now.
xbacklight -set 60
). My laptop uses an Nvidia optimus (I also use bumblebee). Neither of the following work for me:GRUB_CMDLINE_LINUX_DEFAULT="acpi_backlight=vendor"
in grub, andOption "RegistryDwords" "EnableBrightnessControl=1"
in the Device section of/etc/bumblebee/xorg.conf.nvidia
andxorg.conf.nouveau
.