From owner-freebsd-scsi Wed Feb 20 13:57:45 2002 Delivered-To: freebsd-scsi@freebsd.org Received: from rwcrmhc52.attbi.com (rwcrmhc52.attbi.com [216.148.227.88]) by hub.freebsd.org (Postfix) with ESMTP id 05E7137B402 for ; Wed, 20 Feb 2002 13:57:39 -0800 (PST) Received: from gateway.posi.net ([12.236.90.177]) by rwcrmhc52.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020220215738.TMZF1147.rwcrmhc52.attbi.com@gateway.posi.net>; Wed, 20 Feb 2002 21:57:38 +0000 Received: from localhost (kbyanc@localhost) by gateway.posi.net (8.11.6/8.11.6) with ESMTP id g1KLvXf86397; Wed, 20 Feb 2002 13:57:33 -0800 (PST) (envelope-from kbyanc@posi.net) X-Authentication-Warning: gateway.posi.net: kbyanc owned process doing -bs Date: Wed, 20 Feb 2002 13:57:32 -0800 (PST) From: Kelly Yancey To: Joerg Wunsch Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: RBC support patch In-Reply-To: <20020220223124.A9579@uriah.heep.sax.de> Message-ID: <20020220134946.X86372-100000@gateway.posi.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wed, 20 Feb 2002, Joerg Wunsch wrote: > As Kelly Yancey wrote: > > > > They are not broken. READ(6)/WRITE(6) are not mandatory for direct > > > access devices by the standard, but READ(10)/WRITE(10) are. > > > Unfortunately, my copy of the SCSI-2 draft lists READ(10) and > > WRITE(10) as optional for direct-access devices. Otherwise, this > > would be an easy fix to a > > long standing annoyance. :| > > Hmm, after reading the docs again, i have to correct myself: both > are mandatory, either by my SCSI-2 copy as well as by the SCSI-3 > drafts i've got. The latter contain a footnote explaining that the > 6-byte commands have been kept as `mandatory' since some boot > environments require it, while applications are requested to migrate to > the 10-byte commands. > > So perhaps we should simply reverse the logic, use the 10-byte opcodes > as default, and collect the list of (too old) devices that require the > 6-byte CDBs. How does that sound? > > -- > cheers, J"org .-.-. --... ...-- -.. . DL8DTL You are right, SCSI 3 lists both 6 and 10-byte READ/WRITE commands are mandatory. However, SCSI 2 lists both as optional. So we could just key off the INQUIRY results and if the device reports itself as SCSI3 or newer force 10 byte commands, otherwise keep using 6 byte commands. Sounds reasonable to me. What will be interesting is seeing if this would fix all the SCSI->USB quirks along the way (i.e. do they report themselves as SCSI3 conforming?). I'll make up a quick patch and post it for review shortly. Kelly kbyanc@{posi.net,FreeBSD.org} To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message