Question about use of IEEE COMPANY ID in 11-322r2

[Curtis Stevens]

Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1210090_f.htm">HTML-formatted message</a>

Are there any concerns about OUI-36?
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Curtis E. Stevens
Director, Standards & Features Technology
3355 Michelson Dr. #100
Office: 1-1041
Irvine, Ca. 92612
Phone: 949-672-7933
Cell: 949-307-5050
E-Mail: Curtis.Stevens at WDC.com
Remember, you may only be blamed for something if you are actually doing
something.
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of James C
Hatfield
Sent: Monday, October 08, 2012 12:10 PM
To: Gerry Houlder
Cc: T10 Reflector
Subject: Re: Question about use of IEEE COMPANY ID in 11-322r2
T13 has already defined (in ACS-3 rev 4: see A.23.2) that
      bits 31:24 are reserved
      bits 24:0   are the OUI
Thank You !!!
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Jim Hatfield
Seagate Technology LLC
   e-mail:  James.C.Hatfield at seagate.com
   s-mail:  389 Disc Drive;  Longmont, CO 80503 USA
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   fax....: 720-684-2711
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On Mon, Oct 8, 2012 at 12:37 PM, Gerry Houlder
<gerry.houlder at seagate.com> wrote:
I have noted that 11-322r2 (Device crash dump) has a 32 bit field in the
returned data for IEEE COMPANY ID. I'm sure this is because the SATA
equivalent has a 4 byte field for this also. However, the IEEE Company ID is
a 24 bit value.
Neither the SATA version or the T10 version of the crash dump feature has any
guideline about how the 24 bit value is aligned within the 32 bit field.
There is also the issue of SATA being little endian and SCSI is big endian.
This could lead to interpretation problems when comparing crash dump
information from a SATA drive with crash dump information from a SCSI drive
that are from the same manufacturer (and should have the same company ID
value).
I suggest that the 4 byte value should be changed to a 3 byte value plus a
reserved byte. This would take care of how the 24 bit field is aligned. We
should also discuss whether we need to require the bytes to be always little
endian or always big endian regardless of whether the data is from a SATA or
SCSI drive.