This message generated a parse failure. Raw output follows here. Please use 'back' to navigate. From devnull@lkml.org Wed Apr 24 17:17:12 2024 Received: from lml.valinux.com (postfix@lml.valinux.com [198.186.203.19]) by herbie.ucs.indiana.edu (8.9.3/8.9.3) with ESMTP id QAA14812 for ; Wed, 2 Feb 2000 16:34:54 -0500 (EST) Received: from vger.rutgers.edu (vger.rutgers.edu [128.6.190.2]) by lml.valinux.com (Postfix) with ESMTP id 454BE5C8F1; Wed, 2 Feb 2000 12:53:10 -0800 (PST) Received: by vger.rutgers.edu via listexpand id ; Wed, 2 Feb 2000 11:33:12 -0500 Received: by vger.rutgers.edu id ; Wed, 2 Feb 2000 11:32:10 -0500 Received: from panzer.kdm.org ([216.160.178.169]:1455 "EHLO panzer.kdm.org") by vger.rutgers.edu with ESMTP id convert rfc822-to-8bit; Wed, 2 Feb 2000 11:30:24 -0500 Received: (from ken@localhost) by panzer.kdm.org (8.9.3/8.9.1) id NAA44428; Wed, 2 Feb 2000 13:42:07 -0700 (MST) (envelope-from ken) Date: Wed, 2 Feb 2000 13:42:07 -0700 From: "Kenneth D. Merry" To: Drew Eckhardt Cc: Jonas Nickel , Rogier Wolff , linux-kernel@vger.rutgers.edu, linux-scsi@vger.rutgers.edu, phoenix@thesindicate.com Subject: Re: Devices not supporting read-6.... Message-Id: <20000202134207.A44343@panzer.kdm.org> References: <20000202010204.A40068@panzer.kdm.org> <200002022025.NAA20336@chopper.poohsticks.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT X-Mailer: Mutt 1.0i In-Reply-To: <200002022025.NAA20336@chopper.poohsticks.org>; from drew@Poohsticks.Org on Wed, Feb 02, 2000 at 01:25:49PM -0700 Sender: owner-linux-kernel@vger.rutgers.edu Precedence: bulk X-Loop: majordomo@vger.rutgers.edu X-Orcpt: rfc822;linux-kernel-outgoing-dig On Wed, Feb 02, 2000 at 13:25:49 -0700, Drew Eckhardt wrote: > In message <20000202010204.A40068@panzer.kdm.org>, ken@kdm.org writes: > >On Tue, Feb 01, 2000 at 22:40:26 -0700, Drew Eckhardt wrote: > >> In the SCSI-1 spec that some of this conformed to, Read-6 was required. > >> Read-10 was suggested as a good idea. Since some devices Wedged until > >> power cycled when fed a command they didn't support, I figured that > >> using Read-6 until we absolutely positively had to use Read-10 was a > >> fine idea. > > >FWIW, even in the SCSI-1 spec, 10-byte reads were mandatory for CDROM and > >WORM devices, and 6-byte reads were optional. (It is that way in the > >SCSI-2 spec, and I think in the MMC specs as well.) > > I worked off the X3T9.2 REV 17B draft. The above information is from that draft. :) > It covers Direct Access devices, Sequential Access devices, and Printers. It also covers CD (read only direct access) and WORM devices. > In each section, there are tables of 6 and 10 byte supported commands. In > the Direct Access section we have the following: > > Key: M = Command implementation is mandatory. > E = Command implementation is required for SCSI devices that support > device-independent self-configuring software. > > Table 8-1 > Group 0 Commands for Direct-Access Devices > > ============================================================================== > Operation > Code Type Command Name Section > ------------------------------------------------------------------------------ > 08H M READ 8.1.4 > Table 8-22 > Group 1 Commands for Direct-Access Devices > 28H E READ 8.2.2 Key: M = Command implementation is mandatory. E = Command implementation is required for SCSI devices that support device-independent self-configuring software. O = Command implementation is optional. R = Operation code is reserved for future standardization. V = Operation code is available for vendor unique commands. Table 13-1 Group 0 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ [ ... ] 08H O READ 12.1.1 [ ... ] Table 13-2 Group 1 Commands for Read-Only Direct-Access Devices ============================================================================== Operation Code Type Command Name Section ------------------------------------------------------------------------------ [ ... ] 28H M READ 12.2.1 [ ... ] > >The way we handle this in FreeBSD is to specify a minimum command size in > >the function that builds read and write CCBs. > > Under Linux, the CD and disk drivers are completely divorced. When I > wrote the disk driver, I used the smallest command possible for a given > transfer size. The CD driver was cloned from that. > > They should probably share a common direct-access support file that > does that. Ken -- Kenneth Merry ken@kdm.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/