From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:37577 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757522Ab2CEUEt (ORCPT ); Mon, 5 Mar 2012 15:04:49 -0500 Subject: Re: [PATCH 3.3] iwlwifi: always monitor for stuck queues From: Johannes Berg To: "John W. Linville" Cc: Wey-Yi Guy , linux-wireless@vger.kernel.org, stable@vger.kernel.org In-Reply-To: <20120305194644.GF18128@tuxdriver.com> (sfid-20120305_210211_266165_46802003) References: <1330879846-30311-1-git-send-email-wey-yi.w.guy@intel.com> <20120305194644.GF18128@tuxdriver.com> (sfid-20120305_210211_266165_46802003) Content-Type: text/plain; charset="UTF-8" Date: Mon, 05 Mar 2012 21:04:32 +0100 Message-ID: <1330977872.3545.11.camel@jlt3.sipsolutions.net> (sfid-20120305_210453_362702_9BB4FEF0) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2012-03-05 at 14:46 -0500, John W. Linville wrote: > On Sun, Mar 04, 2012 at 08:50:46AM -0800, Wey-Yi Guy wrote: > > From: Johannes Berg > > > > If we only monitor while associated, the following > > can happen: > > - we're associated, and the queue stuck check > > runs, setting the queue "touch" time to X > > - we disassociate, stopping the monitoring, > > which leaves the time set to X > > - almost 2s later, we associate, and enqueue > > a frame > > - before the frame is transmitted, we monitor > > for stuck queues, and find the time set to > > X, although it is now later than X + 2000ms, > > so we decide that the queue is stuck and > > erroneously restart the device > > > > It happens more with P2P because there we can > > go between associated/unassociated frequently. > > > > Cc: stable@vger.kernel.org > > Reported-by: Ben Cahill > > Signed-off-by: Johannes Berg > > Signed-off-by: Wey-Yi Guy > > --- > > So what is the effect of this bug? An unnecessary firmware restart? How often does this happen? Oh, guess I forgot that. The effect is essentially that the firmware restarts unnecessarily, which causes strange things to happen. > It is very late in the 3.3 cycle. Fixes should be for regressions, crashes, etc. Since unfortunately P2P isn't really stable yet and before P2P hardly anyone saw this I suppose it doesn't matter all that much ... johannes