Return-path: Received: from mga02.intel.com ([134.134.136.20]:12867 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753568Ab0A0TDL (ORCPT ); Wed, 27 Jan 2010 14:03:11 -0500 Subject: Re: [PATCH] mac80211: wait for beacon before enabling powersave From: "Guy, Wey-Yi" To: "Luis R. Rodriguez" Cc: Johannes Berg , "linville@tuxdriver.com" , "kalle.valo@iki.fi" , "linux-wireless@vger.kernel.org" , "j@w1.fi" , "buytenh@wantstofly.org" In-Reply-To: <43e72e891001271025s27bbe25cs3c999a885551a4e7@mail.gmail.com> References: <1264511993.25642.9.camel@johannes.local> <43e72e891001271001r2cc39da4ka00a3eef06f6e139@mail.gmail.com> <1264615477.8619.20.camel@wwguy-ubuntu> <43e72e891001271014j667221bqa11d56f3a68f6099@mail.gmail.com> <1264616062.8619.22.camel@wwguy-ubuntu> <43e72e891001271025s27bbe25cs3c999a885551a4e7@mail.gmail.com> Content-Type: text/plain Date: Wed, 27 Jan 2010 10:59:41 -0800 Message-Id: <1264618781.8619.31.camel@wwguy-ubuntu> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Wed, 2010-01-27 at 10:25 -0800, Luis R. Rodriguez wrote: > On Wed, Jan 27, 2010 at 10:14 AM, Guy, Wey-Yi wrote: > > On Wed, 2010-01-27 at 10:14 -0800, Luis R. Rodriguez wrote: > >> On Wed, Jan 27, 2010 at 10:04 AM, Guy, Wey-Yi wrote: > >> > On Wed, 2010-01-27 at 10:01 -0800, Luis R. Rodriguez wrote: > >> >> On Tue, Jan 26, 2010 at 5:19 AM, Johannes Berg > >> >> wrote: > >> >> > Because DTIM information is required for powersave > >> >> > but is only conveyed in beacons, wait for a beacon > >> >> > before enabling powersave, and change the way the > >> >> > information is conveyed to the driver accordingly. > >> >> > > >> >> > mwl8k doesn't currently seem to implement PS but > >> >> > requires the DTIM period in a different way; after > >> >> > talking to Lennert we agreed to just have mwl8k do > >> >> > the parsing itself in the finalize_join work. > >> >> > >> >> Not sure if this is merged yet. If not it might be good to add to the > >> >> commit log a brief about the impact of the fix for distribution > >> >> purposes looking to cherry pick some fixes that may cure some issues. > >> >> > >> >> The impact of this fix is that the DTIM settings of > 1 would now be > >> >> respected in the odd situation a beacon would not be received prior to > >> >> association. Ensuring we use a higher DTIM would mean saving more > >> >> power as it would mean we can sleep longer. > >> >> > >> >> This is not propagated to stable but if it turns out this can enhance > >> >> power save since DTIM might usually be > 1 and the race may be more > >> >> common than we expected we may need a respective stable solution. > >> >> > >> > > >> > It will be nice to see a respective solution for stable since this > >> > impact power save which is very important for certain platform. > >> > >> Well how about your patch for stable then? > >> > > if ok with you and Johannes, I will like to see it happen, the only > > issue is, my patch only address iwlwifi but not mwl8k. > > Oh, what was the issue with your patch and mwl8k? > the patch will call drv_config() and ieee80211_recal_ps() mwl8k driver did not implement PS function, but do require dtim for another reason