Return-path: Received: from crystal.sipsolutions.net ([195.210.38.204]:46376 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757323AbYAXQzU (ORCPT ); Thu, 24 Jan 2008 11:55:20 -0500 Subject: Re: [PATCH] mac80211: enable IBSS merging From: Johannes Berg To: bruno randolf Cc: mcgrof@gmail.com, jirislaby@gmail.com, mickflemm@gmail.com, linux-wireless@vger.kernel.org, linville@tuxdriver.com, Ivo van Doorn In-Reply-To: <200801241226.28394.bruno@thinktube.com> References: <20080118125252.6455.41047.stgit@one> <1201099729.3454.17.camel@johannes.berg> <200801241226.28394.bruno@thinktube.com> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-DRp4eqzo7jYwFCwQe7sb" Date: Thu, 24 Jan 2008 17:55:04 +0100 Message-Id: <1201193704.3454.137.camel@johannes.berg> (sfid-20080124_165547_277591_331A3C2E) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-DRp4eqzo7jYwFCwQe7sb Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > i can see now how you could interpret this as only applying to timers, bu= t i=20 > think that does just not make sense - why would you want to sync timers a= nd=20 > adapt beacon intervals if you don't share the same BSSID? Hmm. Well I thought that was pretty much just for optimising performance but now that I think about it again... > i agree that the standard is quite ambigious when it comes to IBSS, but=20 > practically speaking, it is necessary to merge IBSS cells most of the tim= e if=20 > you want to have IBSS working as expected. therefore i tend to interpret = the=20 > ambigious parts of the standard in a way that will improve functionality. I think "working as expected" is stretching it a bit ;) How do you expect IBSS to work? I'd expect only the simplest use case from it: start IBSS on one station and have another one in the vicinity find it while scanning and join it. That works regardless of merging or not. > please see my last post where i suggest to use: >=20 > + if (rx_status->flag & RX_FLAG_TSFT) > + /* in order for correct IBSS merging we need mact= ime*/ > + mactime =3D rx_status->mactime; > + else if (local && local->ops && local->ops->get_tsf) > + /* second best option: get current TSF */ > + mactime =3D local->ops->get_tsf(local_to_hw(local= )); > + else > + /* can't merge without knowing the TSF */ > + mactime =3D -1LLU; >=20 > instead. Not sure. That's a bit on a fine line, if you have a slow device get_tsf() might be well off and this could trigger a BSSID change in both stations. johannes --=-DRp4eqzo7jYwFCwQe7sb Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR5jC56Vg1VMiehFYAQKwLw/+LVZXHRygamCeC6gsLJKWsEizkRUUj/39 iQ3GzAIL9HkpMBBDfhU2sNt79SQsCdY48Z+34A8ugPXmkMOWabAQNt8U4cL6zDIJ KlyKuLKJ9/VFZa2Lonoj6x6nXExfCKE+CIG4iqIYrAAgO9v40JGKsBfPVP7m35H3 +KCNZ0YLazMaJfAUettd2uGSUZksYatlJ8Zk88dCkrCDx3k16yYcatBhOavRe27V Xs7g7/0RCux5HploSG7m+FaJp36nltQbFzlCMREvqTf70bSsyP3jlM04Q+SzMnRi tKxXn9alwnndR0ifbRW0VzFPkeYIMyF06R51cZStTki7LYYDYBwsp5LlAIhuKUx5 3bSUESpZUJ3YZuntsOhhQIDep+hxpaidTnCEzOoosaP44ymvXFRDuZqBq+qPTle1 WdGAmZDdESdywh+kE3/YIj1JuUpI/jCtbA+IJbv5/pm/lq7BawKaO4hOUeVWyVsb a/ZU3KFuYJCGHG9CyyTJ4HRtiAzcglPT6uCwepn5E52Q1LCW71Umxbnxme0TUQUP U/BGssVCqU6HijPiPi+jYXr6wXSFgd4Sq75QyDpSYKNdW1eJRPYnunEQSpkpqdij R/QDTT09Tm80XPrh7Ec0wxq5AQ+eK43DNnHhRVDyLv+CFvvWdb+C/7v7UDLXG3Mi r7nMHpdOAL0= =W6bw -----END PGP SIGNATURE----- --=-DRp4eqzo7jYwFCwQe7sb--