Control backlight for GeForce FX Go 5200
I would like to turn off my laptop LCD backlight when I shut the lid, in particular when working in the office connected to an external screen (the laptop gets very hot and previous experience with a Dell Inspiron has shown turning off the backlight makes all the difference).
I am using an Dell Inspiron 5150 with GeForce FX Go 5200, running Gentoo linux with vanilla kernel 2.6.7, xorg-x11-6.7.0, and the nvidia module from 1.0-6111.
Just for interest when I run:
xset dpms force off
It blanks the screen but does not turn off the backlight. (Note that I am not really wanting dpms becuase I want the internal panel off but the external display on.) My previous laptop had an ATI GPU and I could used the "radeontool" package to control the LCD. Does something like this exist for the linux nvidia cards so that the backlight can be controlled?