I can set the brightness of my laptop screen already via /proc. I can read and change the value.

Now I've set the value to 33 and then I went into gnome power management and enabled the option that it should reduce the backlight brightness being on battery.

That works, the screen gets darker.

If I now read out the current setting from /proc it still says it's 33. So I assume that there is another node in /proc to be used to control the brightness.

The node I use so far is:


I'm using the nouveau driver. With the nvida driver the brightness can not be controlled.


With the nvidia driver, the brightness can be controlled the same way, if the according option is activated.

This is done under the Device setting in xorg.conf:

Option "RegistryDwords" "EnableBrightnessControl=1"


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.