Re: community PM requirements/issues and PowerOP[Was: Re: So, what's the status on the recent patches here?]

Preece Scott-PREECE
2006-09-17T18:25:18Z

> From: Amit Kucheria
>
> On Sun, 2006-09-17 at 15:40 +0200, ext Pavel Machek wrote:
> > On Sun 2006-09-17 16:28:23, Amit Kucheria wrote:
> > > On Sun, 2006-09-17 at 15:18 +0200, ext Pavel Machek wrote:
...
> > > I was referring to the default method of power save on
> Zaurus on the
> > > Sharp ROMs. It was S-T-D (Flash), IIRC. I do not recall drivers
> > > doing runtime power management on Zaurus; that is a major
> difference
> > > from Nokia 770.
> >
> > I'm pretty sure Zauruses do s-t-ram. Flash is read only
> during normal
> > operation.
> >
> > I'm very sure Sharp zaurus sl-5500 does s-t-ram. After all, it has
> > 16MB of flash and 64MB of ram. Suspend-to-flash is not an option.
> >
> > Pavel
>
> If that is the case, I stand corrected. Did the drivers
> support dynamic idling?
>
> Although something about the time it took to resume still
> bothers me....
> I will try to find time to flash it and check.

Google provided a reference to what appears to be a student
paper on power management in the Zaurus, at:
<http://personals.ac.upc.edu/mpericas/zaurus_project-final.pdf#search=%2
2%22power%20management%22%20zaurus%20linux%22>.

>From the paper, it sounds like it has cpufreq
scaling and a sleep mode that is basically suspend-to-RAM.
This was apparently done via backporting stuff to 2.4.

Scott