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: Wed, 14 Mar 2007 13:44:11 +0100 Message-ID: References: <001d01c76629$06da71a0$2e01a8c0@acksys.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from khc.piap.pl ([195.187.100.11]:41068 "EHLO khc.piap.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161224AbXCNMoN (ORCPT ); Wed, 14 Mar 2007 08:44:13 -0400 In-Reply-To: <001d01c76629$06da71a0$2e01a8c0@acksys.local> (Tosoni's message of "Wed, 14 Mar 2007 12:07:58 +0100") Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Tosoni Cc: linux-serial@vger.kernel.org "Tosoni" writes: >> A flag alone is no help for half-duplex devices, they would need >> a complete handshaking code. > > Not true. > This is also the view of the former maintainer of drivers/serial. It's just reality. If your IC in question does this in hardware - fine, but you still have to support it in the driver, adding a #define XXX doesn't help. "Code talks". > But > obviously neither of you used half duplex devices before. This is your "not true". I was using them, though they weren't modems. > There is no need for handshake, since half duplex is used in master/slave > situations. Not necesarily, there are CSMA/CD-style designs as well as token-ring style. > And I can insure you, that Windows handles this very well, using > only the above-mentioned RTS_TOGGLE flag. That means the DCE does all the buffering and handshaking. I'd say it's not common, most devices are simpler. -- Krzysztof Halasa