Re: ACPI S1 state

["Jared D. McNeill" <jmcneill%invisible.ca@localhost>]

On Wed, 11 Jun 2008, David Young wrote:
> 1 I want to conserve as much battery as possible when the machine
>  is idle.
>
> 2 I don't want to shut down the machine when it is idle.
>
> 3 S1 is the only sleep state that the BIOS on my laptop supports.
>  (S4 *may* work, but I'm not holding my breath.)

S4 would work whenever we gain OSPM hibernation support.

> 4 Slow as waking all of the devices may be, it only takes about
>  one second for the system to become interactive.  It only
>  takes a few seconds longer for the HDD to wake.
>
> 5 If there is a strict wake latency requirement for S1, I am not aware
>  of it.  As best I can tell, it need only wake faster than S2 and S3,
>  and neither of those is an option.

S1 explicitly defines that devices do not lose their state, so this should 
not be necessary. I would rather fix the real problem rather than 
hack around it.

> 6 Compliance with ACPI guidelines/standards is important, but when
>  you get down to it, users want something that can meet both their
>  power-saving and latency requirements.

Agreed, we need per-device Sstate->Dstate mappings. Maybe a 6.0 project :)

Cheers,
Jared