From owner-freebsd-arch@FreeBSD.ORG Sun Mar 21 19:11:05 2004 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D891F16A4CE for ; Sun, 21 Mar 2004 19:11:05 -0800 (PST) Received: from smtp.omnis.com (smtp.omnis.com [216.239.128.26]) by mx1.FreeBSD.org (Postfix) with ESMTP id BBD5743D2F for ; Sun, 21 Mar 2004 19:11:05 -0800 (PST) (envelope-from wes@softweyr.com) Received: from 204.68.178.189 (66-91-236-204.san.rr.com [66.91.236.204]) by smtp-relay.omnis.com (Postfix) with ESMTP id AA355881CF9; Sun, 21 Mar 2004 19:11:03 -0800 (PST) From: Wes Peters To: "M. Warner Losh" , ticso@cicely.de, ticso@cicely12.cicely.de Date: Sun, 21 Mar 2004 19:13:49 -0800 User-Agent: KMail/1.5.4 References: <20040320052007.GC33602@cicely12.cicely.de> <20040320.184336.88475380.imp@bsdimp.com> In-Reply-To: <20040320.184336.88475380.imp@bsdimp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200403211913.49901.wes@softweyr.com> cc: arch@freebsd.org Subject: Re: Opinions about using USB serial numbers X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Mar 2004 03:11:06 -0000 On Saturday 20 March 2004 17:43, M. Warner Losh wrote: > In message: <20040320052007.GC33602@cicely12.cicely.de> > > Bernd Walter writes: > : I have a lot to do with systems using many USB devices of the same > : kind. > : Currently device are named acording to their probing order. > : That result in the problematic that device names can change after > : reboot or replugging in different order. > : > : I would like to add functionality for creating alias devnodes > : including the serial numbers (if the device has one setup). > : E.g. for a ucom(4) device you will get /dev/ucom0 and > : ucom.serialnumber. If the device has no serial numer there will be > : just /dev/ucom0 as befor. > : > : Another solution could be to create the nodes in a tree form: > : /dev/usbchannel0/hubport1/pubport2/ucom > : That would work for devices without serial numbers too, but I > : personally dislike this way. > > I'd rather that we have a generic binding of a device instance number > to a pnp location. > > However, having said that, you can use devd to extract the information > from the node and then create a symbolic link... Using the serial number would give the ability to reliably connect to a specific device, or to know that it is not currently present in the system. For certain embedded applications, that could be very nice. -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC wes@softweyr.com http://softweyr.com/