Return-path: Received: from mms3.broadcom.com ([216.31.210.19]:3021 "EHLO mms3.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759201Ab2IETsd (ORCPT ); Wed, 5 Sep 2012 15:48:33 -0400 Message-ID: <5047AC85.6090704@broadcom.com> (sfid-20120905_214837_888534_6884B9E7) Date: Wed, 5 Sep 2012 21:48:21 +0200 From: "Arend van Spriel" MIME-Version: 1.0 To: "Brad Figg" 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> <5047AC15.8060207@canonical.com> In-Reply-To: <5047AC15.8060207@canonical.com> Content-Type: text/plain; charset=iso-8859-1; format=flowed Sender: linux-wireless-owner@vger.kernel.org List-ID: On 09/05/2012 09:46 PM, Brad Figg wrote: > 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. I will not (hesitate, that is). Gr. AvS