From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-fx0-f158.google.com ([209.85.220.158]:55871 "EHLO mail-fx0-f158.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760693AbZDWIAs (ORCPT ); Thu, 23 Apr 2009 04:00:48 -0400 Received: by fxm2 with SMTP id 2so391631fxm.37 for ; Thu, 23 Apr 2009 01:00:46 -0700 (PDT) To: Johannes Berg Cc: linux-wireless , Marcel Holtmann , "Guy\, Wey-Yi W" , Arjan van de Ven Subject: Re: powersaving when interface is up but not associated References: <1240431356.30082.18.camel@johannes.local> From: Kalle Valo Date: Thu, 23 Apr 2009 11:00:44 +0300 In-Reply-To: <1240431356.30082.18.camel@johannes.local> (Johannes Berg's message of "Wed\, 22 Apr 2009 22\:15\:56 +0200") Message-ID: <87vdovbxzn.fsf@litku.valot.fi> (sfid-20090423_100103_193355_AA476E14) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Johannes Berg writes: > Hi! Hello, > Just had this idea -- when our networking interfaces are UP, but not > actually doing anything, the RF chains consume power. Yes, and also firmware consumes power. For example stlc4550 has a hibernate feature to put the firmware sleep and wake it up quickly. > This is, often, the default state, since you'll have your wifi on due > to NM wanting to find APs, but not associated, for example when on the > road. Sure, you can manually turn it off, but... That's what we do in Nokia Internet tablets. wlancond it putting interface up and down all the time and it's a hack. > However, it doesn't seem necessary. When we are not associated to an AP, > and there are no extra interfaces in mac80211 active like monitor > interfaces, it seems that we could very well turn off the radio while > not scanning. It would be entirely trivial for mac80211 to do this, > probably a 20 line patch or so (need some bookkeeping about why radio is > disabled so it's not just four lines). > > Thoughts? I think it's a good idea. Sometimes I have thought myself that we would need something like this. -- Kalle Valo