Return-path: Received: from youngberry.canonical.com ([91.189.89.112]:39911 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759275Ab2IETq2 (ORCPT ); Wed, 5 Sep 2012 15:46:28 -0400 Message-ID: <5047AC15.8060207@canonical.com> (sfid-20120905_214637_691035_AF7D277E) Date: Wed, 05 Sep 2012 12:46:29 -0700 From: Brad Figg MIME-Version: 1.0 To: Arend van Spriel CC: Seth Forshee , "John W. Linville" , Linux Wireless List , stable , Jonathan Nieder , Stanislaw Gruszka , =?ISO-8859-1?Q?Camale=F3n?= , Milan Bouchet-Valat Subject: Re: [PATCH 2/2] brcmsmac: rework of mac80211 .flush() callback operation References: <1346838562-4818-1-git-send-email-arend@broadcom.com> <1346838562-4818-3-git-send-email-arend@broadcom.com> <20120905165735.GD302@thinkpad-t410> <50478CE9.6040103@canonical.com> <5047A624.7090105@broadcom.com> In-Reply-To: <5047A624.7090105@broadcom.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 09/05/2012 12:21 PM, Arend van Spriel wrote: > On 09/05/2012 07:33 PM, Brad Figg wrote: >> On 09/05/2012 09:57 AM, Seth Forshee wrote: >>> On Wed, Sep 05, 2012 at 11:49:22AM +0200, Arend van Spriel wrote: >>>> This patch addresses a long standing issue of the driver with the >>>> mac80211 .flush() callback. Since implementing the .flush() callback >>>> a number of issues have been fixed, but a WARN_ON_ONCE() was still >>>> triggered because the flush takes too much time. The flush now >>>> makes use of a waitqueue and still has a timeout on which a warning >>>> is given. >>> >>> Brad Figg and I have been testing this patch with a 3.5 kernel. With the >>> patch we're both still seeing the warning from brcms_ops_flush(), and >>> Brad has also seen the "No where to go" message in >>> brcms_c_prec_enq_head(). But the connection continues to work when this >>> happens, whereas previously we had to reconnect, so this is definitely >>> an improvement. >>> >>> Seth >>> >> >> Arend, >> >> Though the driver is definitely better, it is still struggling quite a >> bit as can be seen in the iperf output found at: >> http://pastebin.ubuntu.com/1187578/ >> > > Thanks, Brad > > I was focusing on the warning in the flush callback. I actually could not reproduce the "nowhere to go" message under my ubuntu test laptop. > > The root cause of your problem seems the "nowhere to go". Basically, all packet queues in the driver have reached their limit. In that case packets are simply dropped. > > Could you provide following info: > * cpu info > * wireless device id > * scan data of your AP > * kernel configuration > > If I can download the kernel debian package of your 3.5 kernel from somewhere that would be great. > > Gr. AvS > Arend, I just filed https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1046507 which should contain all this information. If there is _anything_ more I can provide to you or test for you do not hesitate to ask. Brad -- Brad Figg brad.figg@canonical.com http://www.canonical.com