Undocumented option for powerd (from powerd.c source)?

[loveydovey]

Manpage for powerd says:

-s source Enforces method for AC line state refresh; by default, it
is chosen automatically. The set of valid methods is
sysctl, devd and apm (i386 only).

But the source code (powerd.c) says:

typedef enum {
    ac_none,
    ac_sysctl,
    ac_acpi_devd,
#ifdef USE_APM
    ac_apm,
#endif
    ac_acpi_netlink,
}

What the heck is ac_acpi_netlink? Why does powerd require netlink at all? Why is acpi_netlink "method" undocumented in the manual page?

 

[loveydovey]

And this netlink crap is new to 15.0 version, it is not there in 14.3 version.

 

[unitrunker]

Some info here: netlink(4) and snl(3).