Subject: Re: power management and related concerns
To: Garrett D'Amore <garrett_damore@tadpole.com>
From: Jachym Holecek <freza@dspfpga.com>
List: tech-kern
Date: 07/01/2006 15:04:25
# Garrett D'Amore 2006-07-01:
> Well, I've made the mistake of looking at what we currently have in
> NetBSD. And comparing it with some real (our) hardware.
>
> There are few quick points for discussion:
>
> 1) there doesn't seem a clear way to indicate powerfail for a low
> battery condition in sysmon. Should I just be sending init some signal?
Mmm, just notify powerd if present, and do nothing (except for printf)
otherwise? We probably don't want to cpu_reboot(RB_POWEROWN) here, the
battery could be flat-lying...
> 2) No way to indicate overtemp status either
>
> 3) Currently it isn't clear whether you should be registering with APM,
> sysmon, or something else for things like battery status, etc. It would
> be really, really good if drivers didn't have to do _both_ of these
> things. Can we maybe have a sysmon APM compatibility layer? (I guess
> there are some userland apps that "know" about APM. Bletch.)
Route everything to sysmon, keep APM/ACPI-centric userland interfaces
under COMPAT_FOO?
> 4) We need some userland tools to talk to sysmon in base, I think.
> (E.g. to query batteries, etc.)
>
> 5) In many respects, sysmon looks like a good start.
Yes. What I think powerd needs is:
* change event format to something text-based, so that new events
can be created easily, w/o compatibility nightmares
* AF_LOCAL interface so that other parts of userland can inject
events (imagine commandline tool run from smb's tentative
envstatd, or from UPS-over-serial-port software)
Well, there's a lot of work to be done in this area, really.
-- Jachym