Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751824AbZG0Pxa (ORCPT ); Mon, 27 Jul 2009 11:53:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751387AbZG0Pxa (ORCPT ); Mon, 27 Jul 2009 11:53:30 -0400 Received: from tac.ki.iif.hu ([193.6.222.43]:38094 "EHLO tac.ki.iif.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751053AbZG0Px3 (ORCPT ); Mon, 27 Jul 2009 11:53:29 -0400 From: Ferenc Wagner To: Alan Stern Cc: "Carlos R. Mafra" , Greg KH , Alan Cox , Linux Kernel Mailing List , Kernel Testers List , USB list , Kay Sievers , "Rafael J. Wysocki" Subject: Re: [Bisected] [Bug #13821] Replugging USB serial converter uses new device node References: Date: Mon, 27 Jul 2009 17:53:18 +0200 In-Reply-To: (Alan Stern's message of "Mon, 27 Jul 2009 11:34:55 -0400 (EDT)") Message-ID: <87zlaqcec1.fsf@tac.ki.iif.hu> User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2294 Lines: 57 Alan Stern writes: > On Mon, 27 Jul 2009, Carlos R. Mafra wrote: > >> On Sun 26.Jul'09 at 22:28:27 +0200, Rafael J. Wysocki wrote: >>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=13821 >>> Subject : Replugging USB serial converter uses new device node >>> Submitter : Ferenc Wagner >>> Date : 2009-07-18 20:04 (9 days old) >>> References : http://marc.info/?l=linux-kernel&m=124794754015776&w=4 >> >> I was scanning the regressions list and noticed that I could reproduce >> this bug. >> >> So I bisected it to commit 335f8514f200e63d689113d29cb7253a5c282967 >> ("tty: Bring the usb tty port structure into more use"), from Alan >> Cox. >> >> I did not double check if reverting it from -rc4 fixes the issue, >> but I noticed that this patch touches drivers/usb/serial/option.c, which >> is the driver I used to test this problem. >> >> If there is anything else I can do (give more info, test patches etc), >> please let me know. > > Are you certain this really is a regression? Under 2.6.30 and 2.6.27 > the same thing happened if I unplugged a USB serial device while it was > in use. My original report is about unplugging the USB servial device *after* using it. > Can you check whether the device is still being used when you unplug > it? For instance, is there still a pppd process trying to communicate > with the device? I checked and rechecked that the pppd process is already dead by the time I unplug the device. However, the minor number did not increase if I unplugged the device without using it beforehand, as expected. > In short, it seems likely that this is not new behavior but rather the > way usb-serial has worked all along. I didn't experience this problem with 2.6.30: my ppp script was hardwired to use ttyUSB0 and it always worked. Now with 2.6.31-rc3 it does not, as the device node keeps changing. I'll test this with opening ttyUSB directly from the shell, instead of via pppd, and report back whether it makes a difference. -- Regards, Feri. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/