Install https://github.com/patjak/mba6x_bl
Add xorg config (/usr/share/X11/xorg.conf.d/20-intel.conf
):
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "Backlight" "mba6x_backlight"
BusID "PCI:0:2:0"
EndSection
Add mba6x_bl
to /etc/modules
sudo apt-get install efibootmgr
sudo efibootmgr
to check current boot order, will look somewhat like this:
BootOrder: 0080
Boot0000* ubuntu
Boot0080*
BootFFFF*
If 'ubuntu' (which is Mint's EFI identifier) isn't first, change the boot order sudo efibootmgr -o 0