Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:56822 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751597Ab0H0P6p (ORCPT ); Fri, 27 Aug 2010 11:58:45 -0400 Subject: Re: [RFT] mac80211: fix broadcast/multicast data drop on scan From: Johannes Berg To: "Luis R. Rodriguez" Cc: Jouni Malinen , linux-wireless@vger.kernel.org, Kalle Valo , Amod Bodas In-Reply-To: References: <1282887527-23259-1-git-send-email-lrodriguez@atheros.com> <20100827090655.GA15873@jm.kir.nu> <1282923444.4377.13.camel@jlt3.sipsolutions.net> <1282923799.4377.14.camel@jlt3.sipsolutions.net> <1282924294.4377.15.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset="UTF-8" Date: Fri, 27 Aug 2010 17:58:42 +0200 Message-ID: <1282924722.4377.17.camel@jlt3.sipsolutions.net> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2010-08-27 at 08:55 -0700, Luis R. Rodriguez wrote: > On Fri, Aug 27, 2010 at 8:51 AM, Johannes Berg > wrote: > > On Fri, 2010-08-27 at 08:48 -0700, Luis R. Rodriguez wrote: > > > >> > Well, there's no way we can reliably wake up exactly before a beacon by > >> > implementing that in software, hard real-time hasn't been achieved in > >> > Linux yet :-) > >> > >> Keyword here is *exactly*. I don't want to wake up *exactly* at DTIM, > >> only ensure we don't sleep during it and the send buffered frames and > >> multicast traffic data. Why can we not implement this on mac80211? > > > > Well, how long before the beacon do you want to wake up to catch it? > > 1ms? 10ms? 100ms? 1000ms? What if the system is busy? > > I cannot say what would work best, how about half a beacon interval early? Why are we even discussing this anyway? It doesn't matter for a power save implementation since you better offload it to the device so you get as exact timing as you can? johannes