I believe manipulating xgamma(1) indirectly manipulates the screen's backlight in cases where you can't adjust it directly? I haven't tried this myself, but might be worth investigating. In FreeBSD I've used a wrapper called xbrightness which is in ports, but this has not been ported to OpenBSD.
Usually if the fn+[brightness up/down] keys work outside of the OS, for example at POST or in the BIOS/UEFI, then you have hw brightness setting. If not, then you have only software brightness setting, probably dependent on some windows software installed by the laptop vendor.
Last edited by blackhole; 3rd April 2017 at 07:56 AM.
|