Unable to change backlight with either xbacklight or KDE on linux driver 390.59 (linux 4.16.0-2-amd64, GTX 750M)

I’m having a lot of trouble trying to change the backlight brightness on my Debian Sid system. I have a Macbook Pro with a 750M card, and the nvidia-driver package installed.

I have followed the post-installation steps for the nvidia driver, creating the following file:


Section "Device"
   Identifier     "Device0"
   Driver         "nvidia"
   VendorName     "NVIDIA Corporation"
   Option         "RegistryDwords" "EnableBrightnessControl=1;"
   Option         "Backlight"  "acpi_video0"
   BusID          "PCI:0:2:0"

I’ve tried it with and without the two Options, and without the BusID, and every combination in between to no success.

Additionally, my boot parameters are:

ro root=UUID=096d751a-9a92-4dd7-b10c-42b13134b7e9 video.use_native_backlight=1 acpi_osi=Linux acpi_backlight=video

Again, I’ve tried it with every combination of parameters I can think of, and even changing the parameters for acpi_backlight to vendor or native.

In this current config, the


directory is NOT empty and contains


which when root, I CAN change the backlight brightness by issuing a command like the following:

# echo 7 >> /sys/class/backlight/acpi_video0/brightness

Yet, this also only works as root. Also, it is the only way to change the backlight I have found works. xbacklight does not work, and returns no error nor any change in backlight intensity.

I also tried downgrading the driver to 340-xx legacy driver, but that did not change anything.

Nouveau allows me to change the backlight normally with my keyboard buttons, but I need to use the proprietary driver for CUDA.

Any help is appreciated, thanks!!