Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:41475 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751312AbZAIQNP (ORCPT ); Fri, 9 Jan 2009 11:13:15 -0500 From: Christian Lamparter To: Vivek Natarajan Subject: Re: multicast traffic and ath9k Date: Fri, 9 Jan 2009 17:13:12 +0100 Cc: Johannes Berg , "linux-wireless" References: <1231346161.3545.52.camel@johannes> <1231506446.3703.18.camel@johannes> <44EE5C37ADC36343B0625A05DD408C4845A77DAF08@CHEXMB-01.global.atheros.com> In-Reply-To: <44EE5C37ADC36343B0625A05DD408C4845A77DAF08@CHEXMB-01.global.atheros.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Message-Id: <200901091713.12777.chunkeey@web.de> (sfid-20090109_171319_517212_CEB001B2) Sender: linux-wireless-owner@vger.kernel.org List-ID: On Friday 09 January 2009 14:59:25 Vivek Natarajan wrote: > > Johannes Berg wrote: > > > > Is the mc bit > > > checking done only on enabling power save? if set and mc packets are received, > > > how does it automatically go back to sleep and wouldn't there be any conflict > > > between mac80211 and the hw regarding power state since mac80211 is not aware > > > of the mc bit induced state change? > > > I don't think there would be a conflict. mac80211's CONF_PS is always > > only "go to sleep if you can", so receiving multicast traffic would > > obviously imply not being able to go to sleep. When mac80211 then unsets > > the CONF_PS flag you'd just not go back to sleep after being awake for > > MC traffic. > > How does the mac80211 know if the hw is receiving mc traffic or not and > unset the CONF_PS flag accordingly? Am I missing something basic here? > > Maybe p54 (stlc45xx) has the answer for how it goes back to sleep after mc traffic. Well we have a flag to tell the firmware to do the following thing in client mode (while sleeping) "If the PSM object's *_PSM_MCBC flag is set, and a beacon is received with the TIM's multicast traffic bit set, [...] or the LMAC stays awake until the TIM's multicast traffic bit is cleared again from the beacon". see: STSW45X0C LMAC API: page 24 - LM_PSM_MCBC (~ P54_PSM_MCBC) Regards, Chr