Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:45951 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754324AbZEPMtA (ORCPT ); Sat, 16 May 2009 08:49:00 -0400 Subject: Re: Scan while TX/RX'ing a lot of data From: Johannes Berg To: Dan Williams Cc: Holger Schurig , linux-wireless@vger.kernel.org, "Luis R. Rodriguez" , Aeolus.Yang@atheros.com, Senthil Balasubramanian , Gaurav.Jauhar@atheros.com In-Reply-To: <1242429353.10933.32.camel@localhost.localdomain> References: <43e72e890905141052o1f072bc5m4bc5922327617f8b@mail.gmail.com> <1242327298.4227.25.camel@localhost.localdomain> <200905151011.50915.hs4233@mail.mn-solutions.de> <1242429353.10933.32.camel@localhost.localdomain> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-4gE8BHHyK0EvDQXQjISm" Date: Sat, 16 May 2009 14:48:57 +0200 Message-Id: <1242478137.10005.63.camel@johannes.local> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-4gE8BHHyK0EvDQXQjISm Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2009-05-15 at 19:15 -0400, Dan Williams wrote: > Well, what does "background scan" mean? mac80211 will obviously accept > beacons from APs on the same channel and happily add them to the scan > list. Only if powersave/beacon filtering isn't enabled. Actually, mac80211 does beacon filtering itself now, so I don't think this happens any more (I did that on purpose so people don't really rely on the former behaviour) > But a background scan would imply that the card itself is taking > over the decision about when to jump around and scan, basically the same > thing NM is doing, right? When would the card/stack decided to > background scan, and what channels would it background scan on? If it > doesn't do more or less all passive channels, then it wouldn't be that > useful for figuring out the site survey data. I would think that mac80211, while asked to scan when associated, could simply do something like calculating how long it can go off-channel under the current QoS requirements, and then go off-channel for that, wait for the next on-channel beacon and some traffic, scan the next channel(s) again etc. johannes --=-4gE8BHHyK0EvDQXQjISm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIbBAABAgAGBQJKDrY0AAoJEODzc/N7+Qma2mYP93OFNvbAVf1h7l9kXUO/rcUu Z24TmNANtMxBYeHdL1h/KmM+bR/MRfpb9WhDrgVeE8gtbwvSCwen74RaDXpq/Udu 62uCJPQrciPEsXQJxlCNkhQxOEO/TCoOjwtacjwoOWPvM55G8zw6xQ6DkxMuGOOk EhBFI49vP2lyEc/3sfy5wVvJdoqK4ZfylXy7cCdGn9oBUZxFniVt7oTk5mY0hidQ jWGbQ59K0X8FcTpVFgfdhZLZ+478qJfSvX+PGtS2yK8DtyJjtLSzOBSn2QjEsJy0 V4cCV+32XfsbR98Q28T+8ZK7bIODs95yicpoJywP3rNQWtT0PwXoXOsNYtbix6sF okHGstJVv7/UhhAhHi3a6I/AA/MBeph+m8rdRm5Zu+pZDIEgRKDEUKB5Y6ChrJSA c09nHwL3fTVSTllar+OcL5qwUdXemGI3w58OXC5hBK56YQn2VM631G7jXeZb50Ys QTejXbxZVMmE89uoDz9KzzoAUt1tGU6UcEhES2d9uVAXr30BhLomyVqI56SJCvw9 IuGmpv+6QRbUZ5F7jPT4Fxrpz3X4BZqpXaxKRajnzbJrj+9PeERUaRgVf5epyxaq Fos1Y3UZted9ti3xvaD0rJ/1fUFhRL0k6koe0VehSqc7IS4H980Ar5mKjjPCbL3c bxYp0jkz8A8YZX/Wemc= =62VE -----END PGP SIGNATURE----- --=-4gE8BHHyK0EvDQXQjISm--