From nobody Tue May 24 10:50:31 2022 X-Original-To: freebsd-questions@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id C8CFF1B3B169 for ; Tue, 24 May 2022 10:50:39 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from mail2.nber.org (mail2.nber.org [198.71.6.79]) by mx1.freebsd.org (Postfix) with ESMTP id 4L6rZk32nmz3Qr7 for ; Tue, 24 May 2022 10:50:38 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from mail2.nber.org (mail2.nber.org [198.71.6.79]) by mail2.nber.org (8.16.1/8.16.1) with ESMTPS id 24OAoVSK016056 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 24 May 2022 06:50:31 -0400 (EDT) (envelope-from feenberg@nber.org) Date: Tue, 24 May 2022 06:50:31 -0400 (EDT) From: Daniel Feenberg To: Mychaela Falconia cc: freebsd-questions@freebsd.org Subject: Re: Unwanted auto-assertion of DTR & RTS on serial port open In-Reply-To: Message-ID: References: List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-KLMS-Rule-ID: 1 X-KLMS-Message-Action: clean X-KLMS-AntiSpam-Status: not scanned, disabled by settings X-KLMS-AntiSpam-Interceptor-Info: not scanned X-KLMS-AntiPhishing: Clean, 1970/01/01 00:00:00 X-KLMS-AntiVirus: Kaspersky Security 8.0 for Linux Mail Server, version 8.0.1.721, bases: 2022/05/24 03:56:00 #14313470 X-KLMS-AntiVirus-Status: Clean, skipped X-Rspamd-Queue-Id: 4L6rZk32nmz3Qr7 X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of feenberg@nber.org designates 198.71.6.79 as permitted sender) smtp.mailfrom=feenberg@nber.org X-Spamd-Result: default: False [-3.70 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:198.71.6.0/23]; NEURAL_HAM_LONG(-1.00)[-1.000]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[nber.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_MED(-0.40)[198.71.6.79:received,198.71.6.79:from]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-1.00)[-1.000]; RCVD_COUNT_ONE(0.00)[1]; MLMMJ_DEST(0.00)[freebsd-questions]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:26287, ipnet:198.71.6.0/23, country:US]; RCVD_TLS_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[] X-ThisMailContainsUnwantedMimeParts: N On Mon, 23 May 2022, Mychaela Falconia wrote: > Hello, > > I am not a current FreeBSD user (I use Linux at the moment), but I am > asking here in connection with this recent feature addition to FreeBSD: > > https://reviews.freebsd.org/D20031 > > The main purpose of this inquiry is to find out if this newly added > FreeBSD feature really works as it seems at first glance, or if it is > not quite there yet. The man page adds the (-)rtsdtr option in version 13.1: https://www.freebsd.org/cgi/man.cgi?query=stty and I can confirm it is an invalid argument in 13.0. I can't confirm that it works in 13.1, though, only that it is first documented there. You should be able to test it with any old desktop computer pretty easily though. Documented things tend to work. Have you thought of the alternative solution of cutting some wires in the serial cable? Does your device even need those signals? Would it work at a lower data rate? This does remind me of a question I have had myself - which is how does one tell from the bugzilla or review what version a commit refers to? Bugzilla has a Version descriptor, but presumably that refers to the version where the bug is found, not where it is corrected. The word "version" does not appear on the typical Review page. Daniel Feenberg NBER