Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:60505 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752755Ab0LHUaH (ORCPT ); Wed, 8 Dec 2010 15:30:07 -0500 Date: Wed, 8 Dec 2010 15:27:38 -0500 From: "John W. Linville" To: Felix Fietkau Cc: Mohammed Shafi , johannes@sipsolutions.net, linux-wireless@vger.kernel.org Subject: Re: [PATCH 4/4] mac80211: reduce the probe response timeout after beacon loss Message-ID: <20101208202738.GG2423@tuxdriver.com> References: <1290203740-57124-1-git-send-email-nbd@openwrt.org> <1290203740-57124-2-git-send-email-nbd@openwrt.org> <1290203740-57124-3-git-send-email-nbd@openwrt.org> <1290203740-57124-4-git-send-email-nbd@openwrt.org> <4CE734D9.90103@openwrt.org> <4CEA8113.9070806@openwrt.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4CEA8113.9070806@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, Nov 22, 2010 at 03:41:23PM +0100, Felix Fietkau wrote: > On 2010-11-22 7:49 AM, Mohammed Shafi wrote: > > On Sat, Nov 20, 2010 at 8:09 AM, Felix Fietkau wrote: > >> On 2010-11-19 10:55 PM, Felix Fietkau wrote: > >>> Waiting for 500 ms after sending a probe request seems a bit excessive, > >>> especially when doing 5 attempts. If the connection is bad enough to make > >>> multiple requests time out, then user space should try to quickly find a > >>> new AP. > > This might improve fail over roaming to a small extent but as per the > > commit id d1c5091f23fed5195271e2849f89017d3a126521 it was mentioned > > this might affect robustness against 'slow AP's' > > > >> Hmm, don't merge this patch yet, it can cause background scans to > >> trigger reconnects. > >> > > I am not sure how this affects background scan.bgscan will be enabled > > even before the beacon loss and it is based on RSSI(please correct me > > if I am wrong). > I'm not sure either, this showed up in my tests. I'm pretty sure that > this change is not the root cause, but I don't want to see it merged > until the cause is figured out. My guess is that it's related to the > issues with the nullfunc probe request patch that Paul pointed out. > I'll do some more testing after I've fixed that one. I'm dropping this from my queue -- please repost if you decide it is warranted. John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.