I am using ASUS X550J. All my fn functions are working fine(volume, touchpad,...) except brightness control(fn+f5/f6).
How can I fix this?
Run in a terminal
sudo -H gedit /etc/default/grub
And change the line
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=!"
Save the file, run
sudo update-grub
and reboot.
This will enable the Fn+F5 and F6 keys and also lid close/open events.
You may also need to redirect to intel_backlight
in X11 settings.
It can be done by adding /usr/share/X11/xorg.conf.d/20-intel.conf
with this content:
Section "Device"
Identifier "card0"
Driver "intel"
Option "Backlight" "intel_backlight"
BusID "PCI:0:2:0"
EndSection