According to the XRANDR spec [1] the correct property is "Backlight".
[1] http://cgit.freedesktop.org/xorg/proto/randrproto/tree/randrproto.txt
According to the XRANDR spec [1] the correct property is "Backlight".
[1] http:// cgit.freedeskto p.org/xorg/ proto/randrprot o/tree/ randrproto. txt