Re: Need help controlling laptom display brightness via sysctl

From: Kevin Oberman <rkoberman_at_gmail.com>
Date: Thu, 04 Jul 2024 23:02:34 UTC 
On Thu, Jul 4, 2024 at 2:59 PM Anton Shepelev <anton.txt@gmail.com> wrote:

> 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
>
> This is what I used. I have it in /etc/devd/thinkpad.conf. You might use
HP.conf:
notify 100 {
         match "system"                  "ACPI";
         match "subsystem"               "ACAD";
         match "notify"                  "0x00";
         action "/usr/bin/backlight 40; service power_profile $notify";
 };

notify 100 {
         match "system"                  "ACPI";
         match "subsystem"               "ACAD";
         match "notify"                  "0x01";
         action "/usr/bin/backlight 100; service power_profile $notify";
};

notify 100 {
         match "system"                  "ACPI";
         match "subsystem"               "IBM";
         match "notify"                  "0x10";
         action "/usr/bin/backlight +";
};

notify 100 {
         match "system"                  "ACPI";
         match "subsystem"               "IBM";
         match "notify"                  "0x11";
         action "/usr/bin/backlight -";
};

10% changes are more reasonable than 1%. The top two "notify"s set the
screen at 100% on AC and 40% on battery.
-- 
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman@gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683