Comment 24 for bug 762670

Dear Sirs!

I am completely newbie in Linux and in Linux Mint in particular. In my case adding Option "RegistryDwords" "EnableBrightnessControl=1" clause in xorg.conf did not change anything in brightness.

uname -a
Linux Dell-XPS-L702X 4.10.0-38-generic #42~16.04.1-Ubuntu SMP Tue Oct 10 16:32:20 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

Xorg.conf

# nvidia-settings: X configuration file generated by nvidia-settings
# nvidia-settings: version 387.22 (buildd@lgw01-amd64-017) Tue Oct 31 00:34:18 UTC 2017

Section "ServerLayout"
    Identifier "Layout0"
    Screen 0 "Screen0" 0 0
    InputDevice "Keyboard0" "CoreKeyboard"
    InputDevice "Mouse0" "CorePointer"
    Option "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "Module"
    Load "dbe"
    Load "extmod"
    Load "type1"
    Load "freetype"
    Load "glx"
EndSection

Section "InputDevice"
    # generated from default
    Identifier "Mouse0"
    Driver "mouse"
    Option "Protocol" "auto"
    Option "Device" "/dev/psaux"
    Option "Emulate3Buttons" "no"
    Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"
    # generated from default
    Identifier "Keyboard0"
    Driver "kbd"
EndSection

Section "Monitor"
    # HorizSync source: edid, VertRefresh source: edid
    Identifier "Monitor0"
    VendorName "Unknown"
    ModelName "LGD"
    HorizSync 67.0 - 137.0
    VertRefresh 60.0 - 119.0
    Option "DPMS"
EndSection

Section "Device"
    Identifier "Device0"
    Driver "nvidia"
    VendorName "NVIDIA Corporation"
    BoardName "GeForce GT 555M"
EndSection

Section "Screen"
    Identifier "Screen0"
    Device "Device0"
    Monitor "Monitor0"
    DefaultDepth 24
    Option "Stereo" "0"
    Option "nvidiaXineramaInfoOrder" "DFP-2"
    Option "metamodes" "DP-1: 1920x1080_120 +0+0, DP-2: nvidia-auto-select +1920+0"
    Option "SLI" "Off"
    Option "MultiGPU" "Off"
    Option "BaseMosaic" "off"
    Option "RegistryDwords" "EnableBrightnessControl=1"
    SubSection "Display"
        Depth 24
    EndSubSection
EndSection

Please, be so kind, help me in solving that issue. I could not imagine before that impossibility to change display brightness may drive someone crazy.

By the way, I performed all steps concerned brightness described at the following topic. To my regret I got no results.

https://sites.google.com/site/easylinuxtipsproject/display#TOC-Brightness-of-the-display-is-wrong-and-not-adjustable