Re: 2.6: drivers/input/power.c is never built

Nigel Cunningham
2005-02-19T09:15:55Z

Hi.

On Sat, 2005-02-19 at 17:53, Dmitry Torokhov wrote:
> Hi Nigel,
>
> On Saturday 19 February 2005 01:28, Nigel Cunningham wrote:
> > Hi.
> >
> > On Sat, 2005-02-19 at 13:58, Dmitry Torokhov wrote:
> > > On Friday 18 February 2005 18:31, Pavel Machek wrote:
> > > > I believe power and suspend keys should definitely go through
> > > > input. I'm not that sure about battery... Lid is somewhere in
> > > > between...
> > > I think we need a generic way of delivering system status changes to
> > > userspace. Something like acpid but bigger than that, something not
> > > so heavily oriented on ACPI. I wonder if that kernel connector patch
> > > should be looked at.
> >
> > Absolutely. I've been thinking about this too, but haven't yet found the
> > time to put it down on paper/email yet.
> >
> > I think we need a very generic system by which changes in anything
> > remotely impacting on power management (kernelspace or userspace,
> > including ACPI, UPS drivers, keyboard handlers, devices etc) can notify
> > events to a userspace daemon. This daemon can act in accordance with
> > user specified policies (changeable on the fly) to implement system
> > level state changes (suspend to ram/disk, shutdown etc), run time power
> > management
>
> Yep.
>
> > (shutdown a USB hub that just signalled the removal of its
> > last client), logging and so on.
>
> This last example - I don't think the daemon should micro-manage, I think
> USB bus should shutdown the hub automatically without involving userspace.

Yeah. Sort of contradicted what I said next, didn't I :>

> > In some cases, it might set policy but
> > not be actively informed of the details of the application of that
> > policy (we don't feedback loops with a process leaving C3 to notify that
> > it's entering C3!).
> >
> > This implies, of course, not just a generic way of notifying changes,
> > but a generic way of implementing policy.
> >
> > Sound too ambitious, or am I thinking your thoughts after you?
>
> Well, at this moment I only care about delivering the data to userspace,
> the rest (daemon, policies) is although interesting is out of scope for
> me.

I think we need to keep the whole picture in mind though - otherwise we
might find the design is to inflexible or such like.

Regards,

Nigel
--
Nigel Cunningham
Software Engineer, Canberra, Australia
http://www.cyclades.com

Ph: +61 (2) 6292 8028 Mob: +61 (417) 100 574