From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbZHRWi3 (ORCPT ); Tue, 18 Aug 2009 18:38:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751604AbZHRWi2 (ORCPT ); Tue, 18 Aug 2009 18:38:28 -0400 Received: from cantor.suse.de ([195.135.220.2]:58082 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750872AbZHRWi1 (ORCPT ); Tue, 18 Aug 2009 18:38:27 -0400 Date: Tue, 18 Aug 2009 15:36:48 -0700 From: Greg KH To: Bruno =?iso-8859-1?Q?Pr=E9mont?= Cc: Greg KH , Alan Stern , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, "Rafael J. Wysocki" Subject: Re: 2.6.31-rc5 regression: Oops when USB Serial disconnected while in use Message-ID: <20090818223648.GA25659@suse.de> References: <20090808194733.38406075@neptune.home> <20090810154402.GA7701@kroah.com> <20090810191822.26370810@neptune.home> <20090810181306.GA24989@kroah.com> <20090810203501.4d57aa5b@neptune.home> <20090810205115.6871239d@neptune.home> <20090810192954.GA11651@suse.de> <20090818190016.73ce53de@neptune.home> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20090818190016.73ce53de@neptune.home> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 18, 2009 at 07:00:16PM +0200, Bruno Prémont wrote: > Hi Greg, > > Were you able to reproduce this with a FTDI usbserial device? No, I can't find one in my box. I'll go dig in the attic next to try to find on, I knew I had one before... > I just had a short look with 2.6.31-rc6, it crashes harder... once > kernel did panic with general protection fault after reporting > tty_port_close_start: count=-1 > The second time id started output of an Oops but only half of the first > line ever showed up on screen (Intel KMS). > > Note: this was with just usbserial.ko and ftdi_sio.ko rebuilt with > CONFIG_DEBUG_INFO=y in the hope to find out what did access a bad > pointer. (make CONFIG_DEBUG_INFO=y drivers/usb/serial/$module.ko) > > Will retry now with a fresh compile with CONFIG_DEBUG_INFO enabled for > whole kernel and see if I can get better information, eventually > switching to vesa framebuffer in case the partial output happens again. > > This pretty much looks like unbalanced ref-count... Yeah, it sounds like it. More info would be great to have if you can get it. thanks, greg k-h