Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937548AbWLKTB5 (ORCPT ); Mon, 11 Dec 2006 14:01:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S937560AbWLKTB4 (ORCPT ); Mon, 11 Dec 2006 14:01:56 -0500 Received: from mail.gmx.net ([213.165.64.20]:58266 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S937548AbWLKTBz (ORCPT ); Mon, 11 Dec 2006 14:01:55 -0500 X-Authenticated: #20450766 Date: Mon, 11 Dec 2006 20:01:10 +0100 (CET) From: Guennadi Liakhovetski To: Alan cc: Corey Minyard , Tilman Schmidt , linux-serial@vger.kernel.org, Linux Kernel , Hansjoerg Lipp , Russell Doty Subject: Re: [PATCH] Add the ability to layer another driver over the serial driver In-Reply-To: <20061211102016.43e76da2@localhost.localdomain> Message-ID: References: <4533B8FB.5080108@mvista.com> <20061210201438.tilman@imap.cc> <457CB32A.2060804@mvista.com> <20061211102016.43e76da2@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1744 Lines: 39 On Mon, 11 Dec 2006, Alan wrote: > On Sun, 10 Dec 2006 19:23:54 -0600 > Corey Minyard wrote: > > > Nothing has come of this yet. But we have these two requests and a > > request from Russell Doty at Redhat. > > > > It would be nice to know if this type of thing was acceptable or not, > > and the problems with the patch. The patch is at > > http://home.comcast.net/~minyard > > This looks wrong. You already have a kernel interface to serial drivers. > It is called a line discipline. We use it for ppp, we use it for slip, we > use it for a few other things such as attaching sync drivers to some > devices. Alan, my understanding might be wrong, but, I think, line disciplines are there as "protocols" for user-tty interfaces, i.e., you need a user, that opens a tty, sets a line discipline to it, and does io (read/write) over it, and NOT to be completely initialised and driven from the kernel. Whereas, what some users need is a complete in-kernel interface, when either another driver (like in case with the previous poster), or the platform code (linkstation) know that there's a device attached to this UART, know how and WHEN to operate it, and the user doesn't care about it at all. Think of it as about, say, i2c devices, that have user device interface and in-kernel interface, to which you can connect rtc, USB transceivers, that get controlled completely from the kernel TRANSPARENTLY for the user. Thanks Guennadi --- Guennadi Liakhovetski - 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/