Re: [PATCH] ata: ahci: power off unused ports

[Jeff Garzik]

Pavel Machek wrote:
> Hi!
>
> > > > As far as I know the patch has gone nowhere.  I believe that 
> > > > Jeff wanted something more flexible than the module parameter that
> > > > I provided to override the BIOS options.  I am not working on this,
> > > > I figured he had a pretty firm idea what he wanted so he was better
> > > > equipped to write the patch.
> > > Thanks Kristen,
> > >
> > > Can you say which laptops you had tested this on where it saved power?
> > > (Did you test any Thinkpads, in particular?)  I'm wondering if it's
> > > worth trying to forward port your patch as a private mod to my kernel;
> > > 30 to 40 minutes of extra battery life is nothing to sneeze at!
> > >
> > > 						- Ted
> > I tested this on an Intel mobile software development platform 
> > with a newer mobile ICH - the power savings were measured at the actual 
> > component (via probes on the ICH), so I did not measure the power 
> > savings at the wall socket, although I would expect the power savings
> > to be even greater on the other side of the power supply.  So in short,
> > yes, I think it's worth it to give it a try - the patch is pretty
> > unintrusive, so it should be that difficult a port to do.
>
> Can you repost the patch? I believe we should push it and only add
> complex enable/disable functionality if someone needs it...

If you are talking about SATA -- incorrect.

The patch deals with policy, and the user MUST have the ability to 
control this stuff.  Otherwise you create a situation where the user 
might be denied hotplug use in valid cases, or similar negative situations.

	Jeff



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