From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Richter Subject: Re: [PATCH] scsi: Document generic scsi device attributes Date: Sun, 21 Aug 2011 18:22:12 +0200 Message-ID: <20110821182212.118f188d@stein> References: <20110819144427.15191.54676.stgit@beardog.cce.hp.com> <4E4E7F8B.7020502@interlog.com> <20110819154135.GF8422@beardog.cce.hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110819154135.GF8422@beardog.cce.hp.com> Sender: linux-kernel-owner@vger.kernel.org To: scameron@beardog.cce.hp.com Cc: Douglas Gilbert , james.bottomley@hansenpartnership.com, stephenmcameron@gmail.com, akpm@linux-foundation.org, gregkh@suse.de, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On Aug 19 scameron@beardog.cce.hp.com wrote: > On Fri, Aug 19, 2011 at 11:21:47AM -0400, Douglas Gilbert wrote: > > On 11-08-19 10:44 AM, Stephen M. Cameron wrote: > > >From: Stephen M. Cameron > > > > > > > > > > > >+What: /sys/class/scsi_device/..../device/modalias > > >+Date: April, 2007 > > >+KernelVersion: Unknown > > >+Contact: James Bottomley > > >+Description: > > >+ This read only string value contains a string of the form > > >+ "scsi:t-0xXX" where "XX" are two hex digits representing the > > >+ SCSI device type. See also the "type" attribute and table 47 > > >+ in section 8.2.5.1 "Standard INQUIRY data" of the SCSI-2 > > >+ specification. > > > > My copy of SCSI-2 is draft 10b from 1989 and it doesn't have a > > section 8.2.5.1 . Since SCSI-2 was withdrawn over 10 years > > ago perhaps you could use a more recent reference. [I see > > webstore.ansi.org still sells the SCSI-2 standard for $30 .] > > > > SPC-3 is a standard [ANSI INCITS 408-2005; ISO/IEC 14776-453] > > and the relevant section, judging from its last draft, would > > be table 83 in section 6.4.2 . And it is now called the > > "peripheral device type". > > I knew it was a mistake for me to try to figure out what the > proper reference should be. If such things change, maybe > having a reference in there at all is a mistake. The versions of the spec change, as do the chapter numbers and table numbers. But it is always "SCSI Primary Commands" ( <- the command set specification), "INQUIRY data" ( <- the SCSI command response which contains the data that we are talking about here), "Peripheral Device Type" ( <- the number which is written into the modalias). In the last draft revisions of SPC-3 and SPC-4 which were openly published at ftp.t10.org, it is table 83 in section 6.4.2. (Visit archive.org to retrieve those drafts.) But in the words of the same table: "All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the listed standards." :-) > Maybe it should just > say something like, "the numbers correspond to the entries in > the scsi_device_types[] array in drivers/scsi/scsi.c" But - the values come from the target, not from the kernel, - their meaning is defined by ANSI/INCITS T10, not by the authors of linux/drivers/scsi/scsi.c. > since that file is more likely to be close at hand than whichever > spec we might refer to. Maybe call it Peripheral Device Type (PDT, defined by SCSI Primary Commands). -- Stefan Richter -=====-==-== =--- =-=-= http://arcgraph.de/sr/