[ltp] Prevent brightness change for AC events

Vincent Bernat linux-thinkpad@linux-thinkpad.org
Fri, 11 Jul 2014 23:44:09 +0200

 =E2=9D=A6 11 juillet 2014 23:23 +0200, Jochen Spieker <ml@well-adjusted.de=

> Does anybody have an idea where I can disable screen brightness changes
> for AC events?
> My system:
> - X240 w/ full HD IPS panel
> - running Debian sid amd64
> - "Desktop": awesome window manager with a few added programs that I
>   start in ~/.xsession:
>   - xfce4-power-manager
>   - gnome-settings-daemon
>   - xset +dpms
>   - xset dpms 0 0 300
>   + a few unrelated programs
> I didn't find a setting that may be responsible for this behavior in
> either xfce4-power-manager or gnome-control-center. I have
> laptop-mode-tools installed as well but use CONTROL_BRIGHTNESS=3D0 in
> /etc/laptop-mode/conf.d/lcd-brightness.conf. I also took a look into
> /etc/acpi but didn't find anything relevant.

I have the same problem on a Carbon X1 2nd gen. I don't run any power
manager, any settings daemon and I don't use laptop-mode. acpid is not
running either. So, none of them are the culprit.

Moreover, with a similar configuration on an older Lenovo Edge 11, I
didn't have this behaviour.

I am running systemd which may fiddle with some settings.
if (user_specified)
    /* Didn't work, but the user is convinced this is the
     * place. */
        2.4.0-test2 /usr/src/linux/drivers/parport/parport_pc.c