Subject: Re: [linux-pm] [RFC] Runtime power management on ipw2100

From: Oliver Neukum <[email-masked]>
Date: Wed, 31 Jan 2007 14:12:05 +0100

Am Mittwoch, 31. Januar 2007 14:04 schrieb Pavel Machek:
> On Wed 2007-01-31 13:53:20, Amit Kucheria wrote:
> > On Wed, 2007-01-31 at 11:48 +0100, ext Andi Kleen wrote:
> > > On Wednesday 31 January 2007 11:27, Matthew Garrett wrote:
> > > > On Wed, Jan 31, 2007 at 12:13:04PM +0100, Andi Kleen wrote:
> > > > > Matthew Garrett <[email-masked]> writes:
> > > > > > 
> > > > > > PCI seems to require a delay of 10ms when sequencing from D3 to D0, 
> > > > > > which probably isn't acceptable latency for an "up" state.
> > > > > 
> > > > > It might be if the interface has been idle for some time
> > > > > (and the delay is not busy looping of course)
> > > > 
> > > > Hm. How would this interact with receiving packets?
> > > 
> > > The hardware will hopefully have support to wake itself up when that 
> > > happens.
> > 
> > Yes. Low power states without ability to respond to wakeup interrupts
> > would be broken behaviour generally.
> 
> Do you realy expect wifi to save significant ammount of power, while
> still listening for packets on wireless network?

It has a managed mode which gives each station a timeslot. Outside
those slots you could power down, if you can do it quickly.

	Regards
		Oliver