[Pm-utils] low power mode

David Zeuthen david at fubar.dk
Mon May 1 17:06:44 PDT 2006

On Mon, 2006-05-01 at 23:30 +0200, Holger Macht wrote:
> > > Do you mean an Uninteruptible Power Supply aka, an UPS? Yes, HAL and
> > 
> > no, something like:
> > http://www.sps-ltd.com/product/external/max90/max90.htm
> Thanks, Stefan! I'm looking for such a link already for about 20 Minutes
> now ;-)

Ah, that's a clever device. So, the issue is that with this one attached
in the laptop "thinks" it's plugged in while it really isn't, yes?

> > > Sure, what's wrong with changing these settings in the power management
> > > daemons preference dialog? So, for g-p-m you could add these option to
> > > each of the "Running On Battery", "Running On AC" and "Running On UPS"
> > > 
> > >  [ ] Spin down disks when idle
> > >  [ ] Suspend devices not in use
> > >  [ ] ...
> > 
> > Yes, it should IMO go there, not into some "lowpower" method of HAL.

So, while the computer thinks it's on AC the functionality you want,
basically, is to tell the system to conserve battery power as much as
possible in order not to drain too much battery? 

I suppose the power management daemon in question would offer some
option that the user can toggle to always save as much power as possible
- even when on AC power. That's actually a good idea regardless, I think
it makes sense to have a "Sacrifice performance for energy savings"
option for all three profiles under which a system can operate (e.g.
battery, plugged in, on UPS). Richard, I've filed a bug for g-p-m


to implement this; what do you think?

> I didn't want to say that the functionality should go to HAL, but only
>  that there are situations where you have to set the policy manually because the
>  system can't figure it out by itself.

Sure, I don't see either why it's related to pm-utils :-). 

But thanks for making me realize that the "Sacrifice performance for
quality" preference is actually useful since it really reflects the
users desires; e.g. the two users Alice and Bob are different as in

 1. Alice might be OK watching a movie in low quality (using an
    inexpensive codec) because she wants to conserve battery; and

 2. Bob don't mind burning battery and he wants his movie in the
    highest possible quality. 

Things like that...


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