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

Dmitry Torokhov
2005-02-19T06:53:29Z

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.

> 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.

--
Dmitry