I recently re-installed Ubuntu on my MSI GP62 laptop. However, I cannot change the brightness. I have tried many things, including booting with acpi_backlight=vendor and similar combinations.

It should be noted that the output of

ls /sys/class/backlight

is empty. Perhaps as a result, xbacklight and other applications do not work. I am also using the Intel drivers/nouveau. I tried various versions of the Nvidia drivers, but they all result in a login loop, similar to this: Ubuntu 16 Stuck in Login Loop after Installing Nvidia 364 Drivers.

Output of lspci -vnn |grep VGA:

00:02.0 VGA compatible controller [0300]: Intel Corporation Skylake Integrated Graphics [8086:191b] (rev 06) (prog-if 00 [VGA controller])

I am also using the nomodeset kernel parameter - without it I cannot get to the login screen.

Any help would be greatly appreciated!