From owner-freebsd-stable@FreeBSD.ORG Thu Oct 5 20:21:47 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3E6F016A40F for ; Thu, 5 Oct 2006 20:21:47 +0000 (UTC) (envelope-from karl@FS.denninger.net) Received: from FS.denninger.net (wsip-70-169-168-7.pn.at.cox.net [70.169.168.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3CDD643D6A for ; Thu, 5 Oct 2006 20:21:45 +0000 (GMT) (envelope-from karl@FS.denninger.net) Received: from fs.denninger.net (localhost [127.0.0.1]) by FS.denninger.net (8.13.6/8.13.1) with SMTP id k95KLi54012212 for ; Thu, 5 Oct 2006 15:21:44 -0500 (CDT) (envelope-from karl@FS.denninger.net) Received: from fs.denninger.net [127.0.0.1] by Spamblock-sys (LOCAL); Thu Oct 5 15:21:44 2006 Received: (from karl@localhost) by FS.denninger.net (8.13.6/8.13.1/Submit) id k95KLibb012206 for freebsd-stable@freebsd.org; Thu, 5 Oct 2006 15:21:44 -0500 (CDT) (envelope-from karl) Date: Thu, 5 Oct 2006 15:21:44 -0500 From: Karl Denninger To: freebsd-stable@freebsd.org Message-ID: <20061005202144.GA11105@FS.denninger.net> Mail-Followup-To: freebsd-stable@freebsd.org References: <20061005151925.GA1156@FS.denninger.net> <20061005190822.GA15547@icarus.home.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061005190822.GA15547@icarus.home.lan> User-Agent: Mutt/1.4.2.1i Organization: Karl's Sushi and Packet Smashers X-Die-Spammers: Spammers cheerfully broiled for supper and served with ketchup! Subject: Re: Recommendations for a serial port card you can actually BUY? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 05 Oct 2006 20:21:47 -0000 On Thu, Oct 05, 2006 at 12:08:22PM -0700, Jeremy Chadwick wrote: > On Thu, Oct 05, 2006 at 10:19:25AM -0500, Karl Denninger wrote: > > Hi folks; > > > > Ok, one of my pet peeves is coming around to bite me again. > > > > {snip} > > > > I know serial I/O is passe for many, but some of us have applications that > > actually require it, and can't rationally be moved to anything else due > > to external hardware considerations. > > This is in no way flame-bait, nor does it have any negative > implications -- as a fellow SA I'm just curious. Fair enough. > What exactly are you using serial cards for in this day and age? > A serial console server (a la Cyclades TS)? Or is there something > that's more mission-critical (for lack-of better term). > > I guess my question is: what are you using these cards for, and > can whatever the goal is be accomplished by some alternate hardware > (serial-via-USB adaptors/hubs, serial-over-IP, etc.)? Two things: 1. Fax servers running traditional fax modems. There's a HUGE installed base of fax modems that run on POTS lines and there's simply no justification for moving to something like a channelized T1 system for people who need a half-dozen ports (but not 20+!) 2. Embedded control systems. There is some hardware either is RS232 or, for "floor automation" type stuff, is RS-422/485. The latter is easily converted to using a little dongle, but it requires a 232 port on the computer end Both of these applications are timing critical or they don't work at all. Much of the latter hardware is still only available in a serial interface, no matter the cost. It is not high-data-rate by any means (typically 4800 or 9600 bps) but it is what it is. Serial over IP will not work for either. Serial-via-USB might, and I will look into that, but I suspect I'm going to get in trouble with that one, especially if I have to toggle control signals (e.g. DTR, etc) or support hardware flow control (and for the fax servers, you DO need it if you expect things to work correctly.) FreeBSD's USB support has always been somewhat deficient. For example, apcupsd can't talk to their UPSs over the USB bus, even though the software itself knows how, because FreeBSD doesn't know what a UPS is and throws up its hands when you plug it in. I wasn't aware that the USB to Serial converters would work - I can try them, but there are a lot of those out there that don't work right even under Windows - expecting them to under FreeBSD might be asking too much. The problem that is nailing me particularly hard right now is the second one - I have embedded control systems that I speak to over a RS-232 interface (the devices are actually '485 on a common bus but talked to via a 232/485 converter) and it simply does not work on 6.x using the Comtrol driver at all. 100ms delays and the like are one thing - we're talking about delays in characters reaching the application of one second or more, and in some cases either characters or entire (e.g. a burst of characters) are being When you're trying to manage a synchronous polling protocol this sort of error makes the software on the other end throw up in a really ugly way, since it looks like there's a fault in the equipment on the other end or the wire has been compromised. With FreeBSD 5.x being EOL'd this is now turning into a critical problem. I can't in good conscience put packages out there that have been EOL'd nor offer meaningful support on them. While 5.4 has been reasonably stable for some time, that is now declared a "dead" release. 5.5 is similarly on that road. The only right path forward is into the 6.x world, but I can't get there from where I am now unless this problem can be resolved. > BTW -- I completely agree with you about the cost of these cards, > especially so in 2006. There is absolutely no justified explanation > for such a card costing US$1500, or even US$500. These are ICs and > basic PCBs that at most cost US$20 per device -- the profit mark-up > is appalling. I don't mind the $500 cards (the $1500 ones are another matter!) I very much mind that it appears I can't find a board on the market today that works! For FreeBSD to not differentiate between hardware in their lists that is actually deliverable today and that which is historical is problematic when one tries to go shopping. If you look at the current "serial hardware" list you will see a LOT of stuff that simply isn't made any more - and very little that is. I gave up on Specialix a number of years ago after similar problems showed up in some of their drivers for a different OS and they were unwilling to fix them. Digi has always been pretty solid, but they are passe' now and while I have a nice stock of ISA interface cards, finding motherboards with ISA slots is rapidly becoming impossible. Among the PCI cards only Comtrol appears to be really "in the market" with anything current, and driver support in FreeBSD doesn't exist - despite the claim in the Hardware Notes that its "supported", it in fact hasn't worked properly since 6.0. IMHO either FreeBSD's team needs to find a fix for these things or take 'em out of the supported hardware list so that when people go looking they don't waste time (and potentially quite a bit of money) buying something that doesn't function. -- -- Karl Denninger (karl@denninger.net) Internet Consultant & Kids Rights Activist http://www.denninger.net My home on the net - links to everything I do! http://scubaforum.org Your UNCENSORED place to talk about DIVING! http://genesis3.blogspot.com Musings Of A Sentient Mind