Return-path: Received: from mail.gmx.net ([213.165.64.20]:51116 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752018AbZB0K4l (ORCPT ); Fri, 27 Feb 2009 05:56:41 -0500 Cc: linux-wireless@vger.kernel.org Content-Type: text/plain; charset=iso-8859-1 Date: Fri, 27 Feb 2009 11:56:34 +0100 From: "Alina Friedrichsen" In-Reply-To: <18855.48369.413479.945570@gargle.gargle.HOWL> Message-ID: <20090227105634.291200@gmx.net> (sfid-20090227_115644_204612_B4322B47) MIME-Version: 1.0 References: <18855.26210.618690.891378@gargle.gargle.HOWL> <20090227082545.291220@gmx.net> <18855.43002.100899.931613@gargle.gargle.HOWL> <20090227095312.291210@gmx.net> <18855.48369.413479.945570@gargle.gargle.HOWL> Subject: Re: IBSS issues To: Sujith Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello! > Yes, the TBTT is calculated only once after joining the BSS network. What about the following, which is called after scanning? ieee80211_if_config(sdata, IEEE80211_IFCC_BEACON_ENABLED); This calls indirectly the function which looks in the template for the = TSF. > Am not sure I understand the proposal. What would the tsf value in > set_tsf() be ? > 11.1.4 (IEEE802.11-2007) says that the TSF has to be reset to zero on > joining > an IBSS network. We do that correctly. In the praxis setting the TSF should not a problem as log the value is = not higher then the original TSF from the other node. As long the clock= s are working correct and the other node is not moved with nearly light= -speed this shouldn't happen. ;) > To calculate the next TBTT, we > can't use the > HW TSF, since it has just been reset. And the Beacon's timestamp + in= tval > + FUDGE > is what we do in ath9k to get the TBTT for this peer, which I think i= s > correct. > A sniffer shows the beacon generation being evenly distributed. I think the TSF timer keep this value more up-to-date than a static var= iable in RAM, so that e.g. the speed of the CPU has a lower effect on t= he de-sync of this value. Regards Alina --=20 Computer Bild Tarifsieger! GMX FreeDSL - Telefonanschluss + DSL f=FCr nur 17,95 =BF/mtl.!* http://dsl.gmx.de/?ac=3DOM.AD.PD003K11308T45= 69a -- To unsubscribe from this list: send the line "unsubscribe linux-wireles= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html