From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from crystal.sipsolutions.net ([195.210.38.204]:46781 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754996AbYBYXsU (ORCPT ); Mon, 25 Feb 2008 18:48:20 -0500 Subject: Re: mac80211: sta info locking From: Johannes Berg To: Tomas Winkler Cc: "John W. Linville" , Ron Rindjunsky , linux-wireless , Luis Carlos Cobo In-Reply-To: <1ba2fa240802251541r218d5f22j5b3490d20ab508e3@mail.gmail.com> (sfid-20080225_234203_093090_045ED971) References: <1203677069.26341.52.camel@johannes.berg> <20080222143745.GB3067@tuxdriver.com> <1203693409.7082.30.camel@johannes.berg> <20080222155704.GD3067@tuxdriver.com> <1203972413.13162.163.camel@johannes.berg> <1ba2fa240802251450x4ee13b94yb93e64fd9ebfcec8@mail.gmail.com> <1203980105.13162.182.camel@johannes.berg> <1ba2fa240802251512k15b40d65oee774acebdb953e0@mail.gmail.com> <1203981812.13162.187.camel@johannes.berg> <1ba2fa240802251541r218d5f22j5b3490d20ab508e3@mail.gmail.com> (sfid-20080225_234203_093090_045ED971) Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-g1GoXjrqCdk0ar43WCiU" Date: Tue, 26 Feb 2008 00:48:04 +0100 Message-Id: <1203983284.13162.196.camel@johannes.berg> (sfid-20080225_234824_589856_EDAD0ADB) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-g1GoXjrqCdk0ar43WCiU Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > > Thanks. Yes, I do realize that this is a bit intrusive. On the other > > hand, I can't see the code holding the spinlock for longer code/period= s > > of time (nor should it). Or do you think the driver is allowed to call > > into the AMPDU TX setup path while being called from the AMPDU RX setu= p > > path? That would be a bit weird. > > >=20 > TX and RX BA sessions are triggered from different threads of > execution namely rate scaling and RX path. The protected sections are > quite long IMHO including call outs to underlying driver. It is very > likely that both sides decides for BA session at the same times. Yes, but I still can't see how the driver would be calling both RX and TX aggregation functions /within each other/. That's the only thing that really matters since all the frame TX/RX is synchronized and thus the spinlock can't really be contended. Anyway, I need to look deeper into the code or just try or something. > > > Do you have any setup to check your these changes? > > > > Unfortunately not quite yet. I have an 11n AP now though, but broke of > > one of the antennas, I'll need to see how well it works. >=20 > That's bad 11n is too sensitive on antennas setup. Yeah, I know. I don't know why my router has three antennas though knowing that the Broadcom HW only has two chains. > > > Currently there is known possible deadlock when unloading driver whi= le > > > heavy HT traffic. This is happening while trearing down BA session. = I > > > need to solve this as well. > > > > Interesting, where does it deadlock? >=20 > IIRC there is nice loop including queue lock need to dig the > description tomorrow to satisfy your curiosity. Not too important so don't bother. johannes --=-g1GoXjrqCdk0ar43WCiU Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR8NTs6Vg1VMiehFYAQIt6w//Rh3WRq6xFGOWOR6wReQPlUB9EJF/s+MS XBIhghNMlsTQd55nqSE8teDhTAGpvbuZBexoHrZD0PYievsxH6sHhBqjdIAFiixS hbq+zUGSCSUOlVoVYPgBw7djEbi3GEKxidzjC4kxPA+4j2Ask5nCdALgwqiY/S1d SrfYY7E9Dc3CUQpJPtzXKo3zM8oQs3LEJig4gre3ufpeuaLLAp8WG07QyrAhh/gO /Oq0wCfkiQGkuE/VLk1R67MFpnvkt0DmHBqVi+EoriRnZIahvW7qjUu88Ke4LcTE 1UrV6MRx+LpN+GGnFVne7YcajA8n9YLuKurTwNsB5n7u4l0CJfJDRQqhJ6n4VfPx 5jPEl4puRhtCKTxYqI9Bse8DsQQ9jmaH3wIXOnVMmMl/d36kuETxBGoZYvS3aErA fWwMHSx+XG0Eik+97Y7X3/1bl7L3lI1M6ZSBE4jC7FkapT9IKBF4SbwqdSYZwhsv Tp68qGYYrYDyZlnUB9sYf6GT8HI7Ta/m823J/BhqcGJgsvicqI4L7fh4CMoyxvru aP+IPzAMOWXVs6KJip1IBuY2miXdnS8d8avBKE+qAir9XSmkyAb6m9IvV9VC8+ZF 9TsfzYlGXe2AHKNDMqrUikuT0Fu39p2mffAd3jvVRhZbBtKO6xobAy5hr9IgNij7 tIlwLA5sKHU= =CILL -----END PGP SIGNATURE----- --=-g1GoXjrqCdk0ar43WCiU--