From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:52601 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757037Ab3ANQtN (ORCPT ); Mon, 14 Jan 2013 11:49:13 -0500 Date: Mon, 14 Jan 2013 10:49:06 -0600 From: Seth Forshee To: Stanislaw Gruszka Cc: Johannes Berg , linux-wireless@vger.kernel.org, Ben Greear Subject: Re: [PATCH 1/2] mac80211: synchronize scan off/on-channel and PS states Message-ID: <20130114164906.GA3596@thinkpad-t410> (sfid-20130114_174915_676658_8CE1F29C) References: <1356010879-10054-1-git-send-email-sgruszka@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1356010879-10054-1-git-send-email-sgruszka@redhat.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, Dec 20, 2012 at 02:41:18PM +0100, Stanislaw Gruszka wrote: > Since: > > commit b23b025fe246f3acc2988eb6d400df34c27cb8ae > Author: Ben Greear > Date: Fri Feb 4 11:54:17 2011 -0800 > > mac80211: Optimize scans on current operating channel. > > we do not disable PS while going back to operational channel (on > ieee80211_scan_state_suspend) and deffer that until scan finish. > But since we are allowed to send frames, we can send a frame to AP > without PM bit set, so disable PS on AP side. Then when we switch > to off-channel (in ieee80211_scan_state_resume) we do not enable PS. > Hence we are off-channel with PS disabled, frames are not buffered > by AP. > > To fix remove offchannel_ps_disable argument and always enable PS when > going off-channel and disable it when going on-channel, like it was > before. > > Cc: stable@vger.kernel.org # 2.6.39+ > Signed-off-by: Stanislaw Gruszka This patch makes a huge difference in performance and packet loss during software scans in my testing with iperf. Tested-by: Seth Forshee