Function brightness keys doesn't works under Ubuntu 18.04 Nvidia GT755M

I have installed the latest driver available - nvidia-driver-390.
Turns out fn keys for brightness adjusting are not working anymore.
I’ve tried the most common solutions but none of didn’t help:

  1. Set diffeferent values for acpi_backlight in GRUB_CMDLINE_LINUX_DEFAULT paramter.
  2. Set EnableBrightnessControl=1 in X config file.

Seems like a bug.
With nouveau drivers the keys are working.

nvidia-bug-report.log.gz (127 KB)

Hi there,

I’ve tried all of those too and found this one working :
you make a file into this folder /usr/share/X11/xorg.conf.d
the file name should be this: cat 80-nvidia.conf

so this should be like : /usr/share/X11/xorg.conf.d$ cat 80-nvidia.conf

Section “Device”
Identifier “Device0”
Driver “nvidia”
VendorName “NVIDIA Corporation”
BoardName “NVS 3100M”
Option “RegistryDwords” “EnableBrightnessControl=1”
EndSection

If you have nidia x server installed on your machine then you can see there the type of graphics card you are using exactly, in my case it is the “NVS 3100M”, change that line to your own

and paste it into the file as follows:

Section “Device”
Identifier “Device0”
Driver “nvidia”
VendorName “NVIDIA Corporation”
BoardName “NVS 3100M”
Option “RegistryDwords” “EnableBrightnessControl=1”
EndSection

Save it, and reboot.
you will have to make the file with sudo.
Hope it helps you, good luck.