Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754085AbZGWPL3 (ORCPT ); Thu, 23 Jul 2009 11:11:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752751AbZGWPL2 (ORCPT ); Thu, 23 Jul 2009 11:11:28 -0400 Received: from an-out-0708.google.com ([209.85.132.251]:16160 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751844AbZGWPL1 convert rfc822-to-8bit (ORCPT ); Thu, 23 Jul 2009 11:11:27 -0400 MIME-Version: 1.0 In-Reply-To: References: <20090723012140.39f697d2.akpm@linux-foundation.org> From: Kay Sievers Date: Thu, 23 Jul 2009 17:11:12 +0200 Message-ID: Subject: Re: 2.6.31-rc3: replugging USB serial converter uses new device node To: Alan Stern Cc: Andrew Morton , Ferenc Wagner , linux-kernel@vger.kernel.org, alan@lxorguk.ukuu.org.uk, linux-usb@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1539 Lines: 43 On Thu, Jul 23, 2009 at 16:44, Alan Stern wrote: > On Thu, 23 Jul 2009, Andrew Morton wrote: >> On Sat, 18 Jul 2009 22:04:57 +0200 Ferenc Wagner wrote: >> > Since upgrading to 2.6.31-rc3 from 2.6.30, my ttyUSB device number >> > keeps increasing on each replug.  Output of udevadm monitor: > ... >> > Dmesg is available at http://pastebin.com/d516e3e00. >> >> Can anyone say whether this is expected behaviour? > > It depends on whether a program is still holding the old device file > open when the replug occurs. > >> Does it actually cause any observeable problems?  I expect things will >> get ugly once it runs out of range. > > The numbers will get reused after the corresponding device files are > closed. You might find a symlink for ttyUSB devices to the actual device node, which does not depend on the kernel name, in: /dev/serial/ |-- by-id | `-- usb-067b_2303-if00-port0 -> ../../ttyUSB0 `-- by-path `-- pci-0000:00:1d.7-usb-0:1.1.3.2:1.0-port0 -> ../../ttyUSB0 > For further discussion, see this thread: > >        http://marc.info/?t=124828810800002&r=1&w=2 I can't find the original message to reply, but the device node is always deleted and re-created when the device goes away and comes back. Thanks, Kay -- 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/