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archbung

Member

From: Indonesia

Registered: 2016-04-06

Posts: 2

[SOLVED] A problem with xbacklight and NVIDIA Optimus

Hi,

I have an NVIDIA Optimus laptop. I decided to set up my display according to the NVIDIA Optimus wiki page (i.e. I don't use Bumblebee). This is my xorg.conf:

Section "Module"
	Load "modesetting"
EndSection

Section "Device"
	Identifier "nvidia"
	Driver "nvidia"
	BusID "1:0:0"
	Option "AllowEmptyInitialConfiguration"
	Option "RegistryDwords" "EnableBrightnessControl=1"
	Option "Backlight" "intel_backlight"
EndSection

Using the above, the display works fine. But when I tried to set the screen backlight using xbacklight, it doesn't have any effect whatsoever (not even any error message). I've tried following the Backlight wiki , e.g. by trying all the kernel parameter tweak suggested there, to no avail. I could still set the backlight using

 tee /sys/class/backlight/intel_backlight/brightness <<< somenum 

but this requires sudo. I want to be able to set the backlight without sudo, so I can map it into a key in my WM.

Any help is appreciated.

Thanks.

Last edited by archbung (2016-04-06 10:24:36)

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If you just launch it and see what happens, you are guaranteed to succeed -- at seeing what happens
-- Eric Ries

bibek22

Member

From: Nepal

Registered: 2015-09-10

Posts: 90

Re: [SOLVED] A problem with xbacklight and NVIDIA Optimus

This thread should be helpful. Try the C code posted by ewaller.

edit: oops! url tags.

Last edited by bibek22 (2016-04-06 10:14:39)

archbung

Member

From: Indonesia

Registered: 2016-04-06

Posts: 2

Re: [SOLVED] A problem with xbacklight and NVIDIA Optimus

The light-git program solved it for me!
Thanks again for the help.

---

If you just launch it and see what happens, you are guaranteed to succeed -- at seeing what happens
-- Eric Ries