From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262050AbVGKAxy (ORCPT ); Sun, 10 Jul 2005 20:53:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262170AbVGKAxy (ORCPT ); Sun, 10 Jul 2005 20:53:54 -0400 Received: from mxout.hispeed.ch ([62.2.95.247]:7650 "EHLO smtp.hispeed.ch") by vger.kernel.org with ESMTP id S262050AbVGKAxx (ORCPT ); Sun, 10 Jul 2005 20:53:53 -0400 Message-Id: <42D1C33B.40606@khandalf.com> Date: Mon, 11 Jul 2005 02:54:19 +0200 From: "Brian O'Mahoney" Reply-To: omb@bluewin.ch User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050317) X-Accept-Language: en-us, en MIME-Version: 1.0 To: =?ISO-8859-1?Q?Gustavo_Guillermo_P=E9rez?= CC: linux-kernel@vger.kernel.org Subject: Re: [OT] SCSI Printer on AIC78XX without SCSI Terminator References: <200507101921.36332.gustavo@compunauta.com> In-Reply-To: <200507101921.36332.gustavo@compunauta.com> X-Enigmail-Version: 0.90.2.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Md5-Body: c4b6044ad8122de057e672dd28c27008 X-Transmit-Date: Monday, 11 Jul 2005 2:54:45 +0200 X-Message-Uid: 0000b49cec9d9ee7000000020000000042d1c356000241ed00000001000bc188 Replyto: omb@bluewin.ch X-Sender-Postmaster: Postmaster@84-73-132-32.dclient.hispeed.ch. Read-Receipt-To: omb@bluewin.ch X-DCC-spamcheck-02.tornado.cablecom.ch-Metrics: smtp-06.tornado.cablecom.ch 32701; Body=2 Fuz1=2 Fuz2=2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org First, normal (non-differential) SCSI is an OpenCollector bus design which simply wont work without a terminator and is designed to use exactly two(2) terminators, one at each end of the bus, these both provide a pull up and terminate the bus to prevent reflections. Also the longer and faster the bus the more you depend on correct termination e.g. 130 ohm - +3.3V For much more detail, including external terminators please see http://www.scsita.org/aboutscsi/SCSI_Termination_Tutorial.html Second, there is usually a built in terminator in the AIC7xxx adaptor, usually enabled in the SCSI BIOS. Also check your device for negotiable SCSI options, eg SYNC, OFFSET Gustavo Guillermo Pérez wrote: > Hello, I was tried to use a SCSI Printer, onto a AIC78XX (old and new driver), > when driver load, it recognise the Scanner, the Printer and Panel, but may be > the copier doesn't have an internal terminator, and driver hangs forever > discovering unexistent 4th device. I do not wish to dissasemble the copier to > solder the terminator, and I never deal with SCSI HW. Kernel I was tried: > 2.6.7, 2.4.23. but I think the driver does not change from 2.6.7 to 2.6.12. > > I see the doc about this driver but I can't figure out wich of a lot options > can help to not try to discover more than 3 devices... I'll have a chance to > play with this machine the next week, then I'm taking ideas. > > aic7xxx=seltime:2 > this option wait for answer but the device 4º waits forever... > aic7xxx=no_reset > I don't.... > aic7xxx=override_term > mmmmmm > ... > > The new driver support cmdline args? > > If someone can share comment I would appreciate it > > cheers -- mit freundlichen Grüßen, Brian.