Subject: Re: [PATCH RFC] iwlwifi: add basic runtime PM support

From: "Guy, Wey-Yi" <[email-masked]>
Date: Sun, 08 Jan 2012 16:34:11 -0800

On Mon, 2012-01-09 at 09:01 +0800, Yan, Zheng wrote:
> On 01/06/2012 05:47 PM, Johannes Berg wrote:
> > [add linux-wireless]
> > 
> > On Fri, 2012-01-06 at 10:41 +0800, Yan, Zheng wrote:
> >> This simple patch adds open/close based runtime PM support to the iwlwifi driver.
> >> Namely, make the driver suspend the device after shutting down the interface and
> >> resume the device when activating the interface. In my test, suspending the device
> >> can save about 0.4 watt power. The shortcoming is that the device no longer generate
> >> rfkill changes interrupt.
> > 
> > NACK due to that last sentence. There's no way we can live with that in
> > the general case -- and your patch isn't even configurable afaict. And
> > I'm sure polling the rfkill flag would use just as much energy.
> > 
> It's configurable, runtime PM is disabled by default.

Somehow I miss it, how you configure it?

> 
> > There might be some value in this in a system that doesn't have a hard
> > rfkill line, but that means this needs to be configurable since the
> > device can't know whether there's a button or not [1].
> > 
> The patch targets system that only use software rfkill

How you control that?

Wey