From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759471AbZHRRGx (ORCPT ); Tue, 18 Aug 2009 13:06:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759420AbZHRRGw (ORCPT ); Tue, 18 Aug 2009 13:06:52 -0400 Received: from ppp-152-18.adsl.restena.lu ([158.64.152.18]:60173 "EHLO bonbons.gotdns.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759383AbZHRRGw (ORCPT ); Tue, 18 Aug 2009 13:06:52 -0400 X-Greylist: delayed 369 seconds by postgrey-1.27 at vger.kernel.org; Tue, 18 Aug 2009 13:06:51 EDT Date: Tue, 18 Aug 2009 19:00:16 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: Greg KH 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: <20090818190016.73ce53de@neptune.home> In-Reply-To: <20090810192954.GA11651@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> X-Mailer: Claws Mail 3.7.2 (GTK+ 2.14.7; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, Were you able to reproduce this with a FTDI usbserial device? 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... Thanks, Bruno On Mon, 10 August 2009 Greg KH wrote: > > > I have not tried yet with a different USB serial device but will > > > do so soon to see if I can reproduce it there. (the other > > > USBSerial device I have is: 067b:2303 Prolific Technology, Inc. > > > PL2303 Serial Port) > > > > I can't reproduce with this one. > > > > Similar setup, but instead of SheevaPlug (with it's kernel started > > with console=ttyS0,115200 + agetty run by init) I just started > > agetty (same parameters) on a x86 box with uart serial port (e.g. > > that x86 kernel does not have console kernel parameter) and > > connected that one via NullModem cable to the Prolific USBSerial > > converter. > > > > In this case, no matter how often I pull the USBSerial converter > > there is no Oops. > > > > So it must be something that FTDI driver does differently from e.g. > > Prolific one. > > Ok, thanks, I'll dig through my big box of usb devices to try to find > a ftdi device, I was testing this out on a pl2303 device, which is > why I couldn't reproduce it it seems.