Simply add the option acpi_osi=Linux to your GRUB commandline.

To make this a permanent solution you can edit the file /etc/default/grub and append the option to the line

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash”

so that it looks like this:

GRUB_CMDLINE_LINUX_DEFAULT=”quiet splash acpi_osi=Linux”

Don’t forget to run update-grub2 to regenerate the grub menu.