hard disk power down

[Richard Hughes]

On Mon, 2007-05-21 at 15:55 -0400, David Zeuthen wrote:
> > Cheers for doing that - that's useful to know. David, this makes some of
> > the discussion with DannyK moot - what do you think about hdd powerdown
> > from the desktop?
> 
> Hmm, I think this just needs to happen automagically when g-p-m calls
> SetPowerSave() on HAL

Okay, sure, that makes sense.

> http://people.freedesktop.org/~david/hal-spec/hal-spec.html#interface-device-systempower
> 
> e.g. you'd have the option in g-p-m for both the "On AC" and "On
> battery" tabs saying
> 
>  [x] When idle, power down hard disks and peripherals
> that defaults to [x] for "On battery" and [ ] for "On AC". So as far as
> I'm concerned the magic just happens in pm-powersave (which is what
> SetPowerSave() on HAL calls). 

Sure. We've got the pm-utils infrastructure for just that I guess.

> (I also think it's preferable to avoid using hdparm or sdparm for this;
> the kernel driver for the hard drive / controller needs to export a
> power mgmt aware interface that we can easily poke using sysfs.)

Yes, totally agree - any idea for a CC so we can discuss this with the
right kernel ppl?

> The key thing here is this: The desktop user only needs to tweak a
> simple setting (that's all what users care about; "save power or not"),
> and we can expand the mechanism of what this does in pm-powersave.

Sure, thanks for your mail,

Richard.