From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261294AbVDMKiH (ORCPT ); Wed, 13 Apr 2005 06:38:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261296AbVDMKiH (ORCPT ); Wed, 13 Apr 2005 06:38:07 -0400 Received: from khan.acc.umu.se ([130.239.18.139]:35475 "EHLO khan.acc.umu.se") by vger.kernel.org with ESMTP id S261294AbVDMKiC (ORCPT ); Wed, 13 Apr 2005 06:38:02 -0400 Date: Wed, 13 Apr 2005 12:37:58 +0200 From: Tomas =?iso-8859-1?Q?=D6gren?= To: Marcel Holtmann Cc: linux-kernel@vger.kernel.org Subject: Re: [2.4] "Fix" introduced in 2.4.27pre2 for bluetooth hci_usb race causes kernel hang Message-ID: <20050413103758.GA12780@shaka.acc.umu.se> Mail-Followup-To: Tomas =?iso-8859-1?Q?=D6gren?= , Marcel Holtmann , linux-kernel@vger.kernel.org References: <20050408195632.GA17621@shaka.acc.umu.se> <1113053955.9783.57.camel@pegasus> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1113053955.9783.57.camel@pegasus> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 09 April, 2005 - Marcel Holtmann sent me these 1,6K bytes: > Hi Tomas, > > > I have noticed a problem with a race condition fix introduced in > > 2.4.27-pre2 that causes the kernel to hang when disconnecting a > > Bluetooth USB dongle or doing 'hciconfig hci0 down'. No message is > > printed, the kernel just doesn't respond anymore. > > > > Seen in Changelog: > > Marcel Holtmann: > > o [Bluetooth] Fix race in RX complete routine of the USB drivers > > > > Reversing the following patch to hci_usb_rx_complete() makes 2.4.27-pre2 > > up until 2.4.30 happy and does not hang when removing the dongle > > anymore. (bfusb.c has the same patch applied) > > > > 2.6.11.7 does not show the same problem, but has similar code to the > > "fixed" (that hangs) code in 2.4, so the real problem is probably > > somewhere else. > > does the attached patch makes any difference? It works just fine with pristine 2.4.30 and this patch. No deadlocks anymore. /Tomas -- Tomas Ögren, stric@acc.umu.se, http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se