From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: Re: [PATCH RFC] iwlwifi: add basic runtime PM support Date: Fri, 06 Jan 2012 10:47:49 +0100 Message-ID: <1325843269.3330.4.camel@jlt3.sipsolutions.net> References: <4F065F59.2070107@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: wey-yi.w.guy-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, ilw-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, "netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-wireless To: "Yan, Zheng" Return-path: In-Reply-To: <4F065F59.2070107-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-wireless-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org [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. 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]. johannes [1] actually in theory it might be possible to determine whether or not the pin is floating or not? I doubt even that is possible with the HW we have though -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html