From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Halasa Subject: Re: should RTS init in serial core be tied to CRTSCTS Date: Thu, 08 Mar 2007 17:51:28 +0100 Message-ID: References: <8bd0f97a0703011603m794e00f5x875eb68ad0db05de@mail.gmail.com> <200703071019.55896.rgetz@blackfin.uclinux.org> <57354eff0703071330k2395e9c8n58e12f2111dcb25a@mail.gmail.com> <200703080844.32157.rgetz@blackfin.uclinux.org> <20070308134800.GA30023@flint.arm.linux.org.uk> <45F01AA8.7010608@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from khc.piap.pl ([195.187.100.11]:39350 "EHLO khc.piap.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546AbXCHQvf (ORCPT ); Thu, 8 Mar 2007 11:51:35 -0500 In-Reply-To: <45F01AA8.7010608@gmx.net> (Carl-Daniel Hailfinger's message of "Thu, 08 Mar 2007 15:16:08 +0100") Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Carl-Daniel Hailfinger Cc: Robin Getz , Oleksiy Kebkal , Mike Frysinger , Linux Kernel Mailing List , linux-serial@vger.kernel.org Carl-Daniel Hailfinger writes: > Unless you want two machines to monitor each other via serial console and > each of them has only one serial port. It's not perfect, but it works well > enough despite all claims to the contrary. Sure, if you don't need "input" (only "console logger" function and not "initial input/output terminal"). It has nothing to do with the RTS "problem", though. BTW: reasonably working, standard-compliant USB-RS232 converters cost $15 or so. Unfortunately not that all machines have USB ports. I agree with Russell - mixing kernel console and application's port is asking for trouble. OTOH I wonder what does the device in question require WRT the serial port and WRT RTS line in particular. I know there are some half-duplex converters which drive RTS only while sending and which require CTS to send. They are perhaps a bit broken and require some CSMA-alike retransmissions etc. I don't know if one can expect RTS to stay low all the time. Even a simple /sbin/setserial from /etc/rc.* would drive it high for a moment. I'm afraid the only way which makes sense may be using a customized plug. -- Krzysztof Halasa