Re: Need help controlling laptom display brightness via sysctl

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