From owner-freebsd-current@FreeBSD.ORG Mon Dec 8 19:06:53 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 744A91065676 for ; Mon, 8 Dec 2008 19:06:53 +0000 (UTC) (envelope-from mike@sentex.net) Received: from smarthost1.sentex.ca (smarthost1.sentex.ca [64.7.153.18]) by mx1.freebsd.org (Postfix) with ESMTP id 3CAFC8FC21 for ; Mon, 8 Dec 2008 19:06:53 +0000 (UTC) (envelope-from mike@sentex.net) Received: from lava.sentex.ca (pyroxene.sentex.ca [199.212.134.18]) by smarthost1.sentex.ca (8.14.3/8.14.3) with ESMTP id mB8J6p3p066039; Mon, 8 Dec 2008 14:06:51 -0500 (EST) (envelope-from mike@sentex.net) Received: from mdt-xp.sentex.net (simeon.sentex.ca [192.168.43.27]) by lava.sentex.ca (8.13.8/8.13.3) with ESMTP id mB8J6oha042222 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Mon, 8 Dec 2008 14:06:50 -0500 (EST) (envelope-from mike@sentex.net) Message-Id: <200812081906.mB8J6oha042222@lava.sentex.ca> X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Mon, 08 Dec 2008 14:06:48 -0500 To: Marcel Moolenaar From: Mike Tancsa In-Reply-To: References: <200812081621.mB8GLMxB041498@lava.sentex.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Scanned-By: MIMEDefang 2.64 on 64.7.153.18 Cc: freebsd-current@freebsd.org Subject: Re: uart vs sio differences ? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Dec 2008 19:06:53 -0000 At 01:49 PM 12/8/2008, Marcel Moolenaar wrote: >On Dec 8, 2008, at 8:21 AM, Mike Tancsa wrote: > >>Unfortunately, we only control the FreeBSD side of things and the >>other end of the serial connection is a windows app we dont >>control. Everything seems to work ok from our side, but the other >>side which we dont control seems to be missing some things we are >>sending it and vice versa. > >It looks to me that flow-control is disabled, is that right? > >Not only does uart(4) make use of the larger buffer of the >hardware, it's also more efficient under puc(4) than sio(4) >is because of the use of the serdev I/F. It's possible that >the receiver can not keep up when uart(4) is used. A serial >line analyzer should tell you more... Hi, Yes, flow control is supposed to be disabled. When we hook up a serial line analyzer, the behaviour is rather odd. We only use 1200bps, so I dont think its a speed issue. Also, as part of the protocol, we poll the other side. We send a 3 byte poll, which the Windows side always sees, and it sends us back a 1 byte answer, which we see fine. However, when the Windows side has "something to say", it will send a different 1 byte response (which we get) and then the data, which is approximately 100 to 200 bytes which we only get about 30 bytes of. ---Mike