Backlight is reduced on LVDS when an external vga monitor is connected. Using a toshiba laptop with GeForce 7600 Go. xbacklight and xgamma don't work, they do nothing. I guess it's another issue: https://bugs.freedesktop.org/show_bug.cgi?id=12723 For informations, I have the same issue with nvidia driver: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=+%0D%0A475651
It's related to kernel. Since I have updated kernel from 2.6.25 to 2.6.26, backlight is normal.
As noted this is a kernel, not driver, problem
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