I wrote:
> I need your help in setting up the brightness control on
> HP 15-b0xx laptop via sysctl.
I was infored that this ability has been discountinued in
favour of the backlight utility, so I gave up and wrote the
following devd rule:
notify 10
{ match "system" "ACPI" ;
match "subsystem" "Video" ;
match "type" "brightness" ;
action "/usr/bin/backlight $notify"; };
This changes brightness by tiny 1/100 steps, but this is
by desing of the HP engineers...
References:
1. https://man.freebsd.org/cgi/man.cgi?query=devd.conf
2.
https://www.davidschlachter.com/misc/freebsd-acpi_video-thinkpad-display-brightness
