From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756906Ab2ADUyf (ORCPT ); Wed, 4 Jan 2012 15:54:35 -0500 Received: from mail-ee0-f46.google.com ([74.125.83.46]:33345 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756825Ab2ADUyd (ORCPT ); Wed, 4 Jan 2012 15:54:33 -0500 Message-ID: <4F04BC85.9060803@suse.cz> Date: Wed, 04 Jan 2012 21:54:29 +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: Alan Cox CC: Dave Jones , Linux Kernel , Jiri Slaby Subject: Re: serial ports now asserting DTR and RTS during boot; breaks connected hardware References: <20120103153707.GA12771@redhat.com> <20120103160655.69107c93@pyramind.ukuu.org.uk> In-Reply-To: <20120103160655.69107c93@pyramind.ukuu.org.uk> 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 05:06 PM, Alan Cox wrote: > On Tue, 3 Jan 2012 10:37:07 -0500 > 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. >> >> 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 ? > > Looks like your userspace to me at first glance. > > ftdi_sio sets up the modem lines in set_termios. Set_termios is called > from ftdi_open. ftdi_open is triggered by userspace. > >> > The following code in the ftdi_sio driver is one suspect but this behavior >> > happens on 8250 UARTs also so it is systemic now, > > Likewise 8250 sets up the lines in serial8250_startup. This is called via > uart_startup which is called via open. Ok, let's apply the cut&paste rule. Does uninstalling ModemManager fix the issue? -- js suse labs