From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756727Ab2ADSoE (ORCPT ); Wed, 4 Jan 2012 13:44:04 -0500 Received: from mail-we0-f174.google.com ([74.125.82.174]:47204 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754084Ab2ADSoB (ORCPT ); Wed, 4 Jan 2012 13:44:01 -0500 Message-ID: <4F049DEA.30506@suse.cz> Date: Wed, 04 Jan 2012 19:43:54 +0100 From: Jiri Slaby User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0) Gecko/20111223 Thunderbird/10.0 MIME-Version: 1.0 To: Dave Jones , Linux Kernel Subject: Re: serial ports now asserting DTR and RTS during boot; breaks connected hardware References: <20120103153707.GA12771@redhat.com> <4F03262D.8090506@suse.cz> <20120103161310.GA8727@redhat.com> In-Reply-To: <20120103161310.GA8727@redhat.com> X-Enigmail-Version: 1.3.4 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/03/2012 05:13 PM, Dave Jones wrote: > On Tue, Jan 03, 2012 at 05:00:45PM +0100, Jiri Slaby wrote: > > On 01/03/2012 04:37 PM, Dave Jones wrote: > > > Jiri, > > > We got this report from a user who notes a change in behaviour for > > > his serial hardware over the last few kernel versions. > > > > Hi! > > > > I'm busy right now, however just after a quick look, it may be related to: > > https://lkml.org/lkml/2011/12/6/573 > > > > I'll take a look later. > > thanks. I'll dig a little deeper. > > > > https://bugzilla.redhat.com/show_bug.cgi?id=771010 > > > > > > This sounds like it might be related to your DTR/RTS changes back in March 2011 maybe ? > > > > What changes do you mean? In serial-core.c? Thaat one is not used by USB > > serials. Hence this wouldn't occur with FTDI. > > yeah, 303a7a1199c20f7c9452f024a6e17bf348b6b398 and c7d7abff40c27f82fe78b1091ab3fad69b2546f9 > jumped out at me, as they were they only things that changed DTR/RTS handling > (at least mentioned in changelog) in recent times. Rollback. The two commits are about uart. So they don't as well affect FTDI. > The user mentions that it also affects 8250, though your point may mean > that this is caused by something further up in the serial/tty code. Or userspace. Try what Alan suggested. And ensure that FTDI is really affected. Sometimes bug reporters do mistakes. -- js suse labs