[Pm-utils] low power mode

[David Zeuthen]

On Mon, 2006-05-01 at 20:53 +0200, Holger Macht wrote:
> But there are situations where you definitely need to change the policy
> manually. Imagine an external power supply. I don't know what the english
> term is, it's just a big battery which you can plug into the usual ac
> interface. It's no battery, but some kind of limited power resource with
> which you can even charge your internal batteries. 

Do you mean an Uninteruptible Power Supply aka, an UPS? Yes, HAL and
g-p-m supports those (arguably only the USB hiddev ones yet) too, see
http://blog.fubar.dk/?p=65 ; Also, I believe nowadays g-p-m just gives
you another tab "Running on UPS" in the configuration dialog
http://people.freedesktop.org/~david/g-p-m-prefs.png if you plug in an
UPS. 

> The system doesn't
> recognize if the power source is "limited" or not. And to change the
> policy to "powersave" in this case isn't only something experienced users
> might want to set.

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
 [ ] ...

just like you can already tweak the LCD brightness on laptops.

Personally I'm not sure there is any convincing use-case for these extra
options so I'm not really sure I want pm-utils to support these as
parameters (e.g. pm-setlowpower would take arguments on what exactly to
do). I could be wrong though, I'm not sure I've seen any convincing
argument for this.

    David