Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:54568 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752108AbZCYUJw (ORCPT ); Wed, 25 Mar 2009 16:09:52 -0400 Subject: Re: wireless powersaving (in NM?) From: Johannes Berg To: Kalle Valo Cc: Dan Williams , "Guy, Wey-Yi W" , linux-wireless , Matthew Garrett , Marcel Holtmann In-Reply-To: <1238011579.4320.169.camel@johannes.local> (sfid-20090325_210659_076895_F94E2630) References: <1237891149.4320.73.camel@johannes.local> <87ab7bqa21.fsf@litku.valot.fi> <1237978630.4320.150.camel@johannes.local> <87ab791isj.fsf@litku.valot.fi> (sfid-20090325_205334_758597_39212B61) <1238011579.4320.169.camel@johannes.local> (sfid-20090325_210659_076895_F94E2630) Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-qigyc66DGB72AhX186Q8" Date: Wed, 25 Mar 2009 21:09:20 +0100 Message-Id: <1238011760.4320.171.camel@johannes.local> (sfid-20090325_210955_485092_48886AD7) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-qigyc66DGB72AhX186Q8 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2009-03-25 at 21:06 +0100, Johannes Berg wrote: > > > I'm just worried that we'll require a whole bunch of different > > > interfaces. Yes, in theory there isn't much to control, but iwlwifi > > > firmware for example can, as far as I interpret the code, dynamically > > > vary the listen interval. > >=20 > > You mean the wakeup interval? For me, listen interval means the > > maximum time AP is willing to buffer frames for a STA. >=20 > No, I mean the listen interval in the assoc request frame. ... > > I think stlc45xx/p54 even had something > > similar. But honestly, I don't know if this kind of trickery is > > useful. Why not directly go to the longest wakeup interval > > immediately? >=20 > But listen interval * beacon interval determines latency. although, of course, the listen interval in the assoc request is just the local max -- since the AP already sets the TIM bit as soon as it has data buffered we can wake up earlier if we want to. In a sense, therefore, the listen interval determines the maximum latency we and the AP are willing to put up with. johannes --=-qigyc66DGB72AhX186Q8 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJJyo9uAAoJEKVg1VMiehFYVTIP/1LbAshE5+a8uduV21mPbGY2 9kXG01a3g0imXyw7ky5tSQ29Mgx4A2IS6S7rChyCiBXnQxnVCpuHFFPE1N0OQHv1 MP+vcc57WFWOJq+u/ZALWexzL+5/NIrCuNAAGwpJbOO4V0GC9NPuff73awZYREmm zvqgwGTwSee9fvBr7THEX/iG0ZjFyVY9yRIdYyaD1UiMmulnoX+ECtnrW8CpsC2P b6FTM/muZ3C0aAqI/TprdS7PLhU/Ff/5htaeCPLyMHMLo9saiDkn3RHa38qWBOEC iixVj4b/41P72sH5LW165eSZQ8AZyXq9E19Xh11GGH+EdMvsSTnW5kFLlNlpBmM4 +2053cn8ksQ7v16ktjSZow3WCvcwN/D0talcQlBqOwPRgdIdvMTf5XvAZ1Cnq9CM zMu+fH75k/7k4+07sKgbWz4LsxBrpOoJ21bKzoCB8wr68re2GjmYg891Ptz64zHV 8h9EQlCYFmvjX9n+L2uh5bfc0E9IZKfjSfLsbuLwLGgzhNrSCsrS2Xpe3eATtMJ/ g7JRuOCkBiXfqJo6NR3ZRa7VK+YfggiKTRHcr7SxnfU3C+aDDJ/G9F+Hbtcy1zYN Htvv/L8Dwehbgffsvfv333AiET6m6upE9CWpJeJ0qxx4BRQYHtQuEpTjzSPzmF91 brYPLXbvtD+WO2hVKlRn =6JuA -----END PGP SIGNATURE----- --=-qigyc66DGB72AhX186Q8--