xbackligth

• Add to the file /etc/default/grub : GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_osi= acpi_backlight=intel"
• Regenerate grub file with sudo grub-mkconfig -o /boot/grub/grub.cfg
• In order to brightness to obtain the goo backlight, add a *.conf file to the folder /etc/X11/xorg.conf.d/ with:

Section "Device"
    Identifier  "Card0"
    Driver      "intel"
    Option      "Backlight"  "intel_backlight"
EndSection