From owner-freebsd-hackers@freebsd.org  Fri Oct 20 15:18:23 2017
Return-Path: <owner-freebsd-hackers@freebsd.org>
Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8D1FEE385C6
 for <freebsd-hackers@mailman.ysv.freebsd.org>;
 Fri, 20 Oct 2017 15:18:23 +0000 (UTC)
 (envelope-from byond.lenox@gmail.com)
Received: from mail-it0-f53.google.com (mail-it0-f53.google.com
 [209.85.214.53])
 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
 (Client CN "smtp.gmail.com",
 Issuer "Google Internet Authority G2" (verified OK))
 by mx1.freebsd.org (Postfix) with ESMTPS id 5A1B07EE38;
 Fri, 20 Oct 2017 15:18:23 +0000 (UTC)
 (envelope-from byond.lenox@gmail.com)
Received: by mail-it0-f53.google.com with SMTP id 72so13794917itk.3;
 Fri, 20 Oct 2017 08:18:22 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:mime-version:in-reply-to:references:from:date
 :message-id:subject:to:cc;
 bh=PDaP5qNPPP+I3xDQDY7KDFE012xVswoXxq37UzkmYFg=;
 b=r67ckP1BZSjWRUC0XGOvprN+cbu+1G7/3d6yUS6T5Iq3S5cDYAhB2Uw21vz9atKqZ3
 fjm+puQ1QUZLfW4AAuYG14F14C5BiqT01hdJLryPyWYA17G/7dKG9OSgmeobReBNls/C
 OE3AxwYDDaMJVnrWsKH8E7jSrGZWXUifhKLbaMW/cF79L95Ag6FKyJjaZLfbyBOp0NN1
 EguCDjpJvcxmrXLPuHFQ83mj4fOGqfMg2T2qhzk9Oa5HtLTBqWNb64/oWQ6kB7uF62MM
 OE3EpPyU58tipPs+Zv49m4o+DcgI0YpMLh7EHyUIvYktvIOKdofPRBcOiCt0WcxqwKNW
 IQTg==
X-Gm-Message-State: AMCzsaUeXfWQQdScf8KNxyH9bXjXJcJX29bnyJPNAOiGnbu9DaDy9JFZ
 HD1aVXOXhqfKL+F0jitQKv+WYFVt
X-Received: by 10.36.22.13 with SMTP id a13mr1396385ita.69.1508512700347;
 Fri, 20 Oct 2017 08:18:20 -0700 (PDT)
Received: from mail-it0-f48.google.com (mail-it0-f48.google.com.
 [209.85.214.48])
 by smtp.gmail.com with ESMTPSA id r79sm613647ita.0.2017.10.20.08.18.20
 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
 Fri, 20 Oct 2017 08:18:20 -0700 (PDT)
Received: by mail-it0-f48.google.com with SMTP id r127so13785586itb.5;
 Fri, 20 Oct 2017 08:18:20 -0700 (PDT)
X-Google-Smtp-Source: ABhQp+SMSXp1bnKNL7g8607M9vs7a4dVMqPaZ0FOEdkn9HXSbBPw60hpTL3hyw+1WDsHraFYr0CGAF4Lv+ypLC80wfk=
X-Received: by 10.36.178.19 with SMTP id u19mr2872514ite.64.1508512699792;
 Fri, 20 Oct 2017 08:18:19 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.107.23.129 with HTTP; Fri, 20 Oct 2017 08:17:59 -0700 (PDT)
In-Reply-To: <1508511786.1383.50.camel@freebsd.org>
References: <CACpH0Md0ckYH6k5ufAwCoc-_ThtJHrV9+dUtp66+SSjVuyhpxA@mail.gmail.com>
 <1508425713.1383.6.camel@freebsd.org>
 <CACpH0MfaP+0BY-1VqbnTQXe9xtLpU3+opYaNpRQC1so0C5iKmw@mail.gmail.com>
 <1508432312.1383.18.camel@freebsd.org> <20171019172246.GU2473@kib.kiev.ua>
 <CACNAnaHL+pW4mqckFsu0Pisz5EWxGoD5AicXXpT1wW9xaiZonQ@mail.gmail.com>
 <1508511786.1383.50.camel@freebsd.org>
From: Kyle Evans <kevans@freebsd.org>
Date: Fri, 20 Oct 2017 10:17:59 -0500
X-Gmail-Original-Message-ID: <CACNAnaE4Cn50_h7mMtjxOm0xt1vXZom-orAhThzS+W-0rt65dg@mail.gmail.com>
Message-ID: <CACNAnaE4Cn50_h7mMtjxOm0xt1vXZom-orAhThzS+W-0rt65dg@mail.gmail.com>
Subject: Re: We do serial differently.
To: Ian Lepore <ian@freebsd.org>
Cc: Konstantin Belousov <kostikbel@gmail.com>,
 FreeBSD Hackers <freebsd-hackers@freebsd.org>, 
 Zaphod Beeblebrox <zbeeble@gmail.com>
Content-Type: text/plain; charset="UTF-8"
X-Content-Filtered-By: Mailman/MimeDel 2.1.23
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
 <freebsd-hackers.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
 <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 20 Oct 2017 15:18:23 -0000

On Fri, Oct 20, 2017 at 10:03 AM, Ian Lepore <ian@freebsd.org> wrote:

> On Fri, 2017-10-20 at 08:36 -0500, Kyle Evans wrote:
> > This doesn't seem to necessarily be true with ucom(4) bits. I put in a
> bit
> > of effort to try and get devel/libserialport to stop setting DTR when it
> > probes /dev/cuaU* to no avail. As a consequence, connected Arduinos
> > constantly reset when devel/arduino18 is open unless the serial
> > monitor/plotter is also open.
> >
> > I can appreciate that +DTR is a sensible default here, but it would be
> nice
> > if it could be configured with the .init node.
>
> Hmm.  You mention the .init node, does setting -hupcl in the .lock node
> fail to suppress toggling DTR as well?  That, I think, would be a bug.
>
> -- Ian
>

Yeah, that also fails to suppress it. For documentation purposes, this is
the exact device/driver I'm working with:


ugen0.2: <Arduino www.arduino.cc product 0x0043> at usbus0
umodem0 on uhub0
umodem0: <Arduino www.arduino.cc product 0x0043, class 2/0, rev 1.10/0.01,
addr 9> on usbus0
umodem0: data interface 1, has CM over data, has break


When I last poked at it, I think I had decided that this line:
https://svnweb.freebsd.org/base/head/sys/dev/usb/serial/usb_serial.c?view=markup#l735

was the culprit and blatantly ignoring any configuration, but this isn't
exactly an area that I'm familiar with so I assume there might be something
elsewhere that I'm missing.