From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752961AbdKGIxb (ORCPT ); Tue, 7 Nov 2017 03:53:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43714 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752620AbdKGIx3 (ORCPT ); Tue, 7 Nov 2017 03:53:29 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7CC794E028 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=sgruszka@redhat.com Date: Tue, 7 Nov 2017 09:53:28 +0100 From: Stanislaw Gruszka To: Richard Genoud Cc: Helmut Schaa , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org Subject: Re: Soft lockup in rt2x00usb_work_rxdone() Message-ID: <20171107085327.GA11380@redhat.com> References: <1509983829.10974.2.camel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1509983829.10974.2.camel@gmail.com> User-Agent: Mutt/1.8.3 (2017-05-23) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Tue, 07 Nov 2017 08:53:29 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi On Mon, Nov 06, 2017 at 04:57:09PM +0100, Richard Genoud wrote: > I get a soft lock-up while unbinding the USB driver on a TP-Link TL-WN727Nv3 (chipset 5370): > > # echo 1-2.2 > /sys/bus/usb/drivers/usb/unbind > watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [kworker/u2:3:308] ... > I can trigger this each time. I can not reproduce this on my system (I'm using 4.14.0-rc6, but I don't think it's an issue). I think the problem may be caused by usb host controler driver, which can be different on your system. Does ftrace work on your platform ? If so could you use ftrace to provide rt2x00 functions trace when the probllem happen ? 3 short articles how to configure and use ftrace are here: https://lwn.net/Articles/365835/ https://lwn.net/Articles/366796/ https://lwn.net/Articles/370423/ Thanks Stanislaw