Download microcode proposals

Kevin D Butt kdbutt at us.ibm.com
Fri Jun 6 09:43:43 PDT 2014


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1406062_f.htm">HTML-formatted message</a>

Bill,
IBM has products that use the MODE SPECIFIC field setting on the last 
segment and uses that regardless of what was set in previous segments 
(though  we do reject invalid values at all times).  Therefore, using the 
value in the first segment and forcing a reject for subsequent 
non-matching values would make IBM devices non-compliant.
IBM votes for using the value in the last segment and not requiring 
consistent values throughout all the segments.	In reality, only the last 
segment causes an action, all the others are just sending portions of the 
image.
Thanks,
Kevin D. Butt
SCSI Architect, Tape Firmware, T10 Standards
Data Protection & Retention
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt at us.ibm.com
http://www-03.ibm.com/servers/storage/ 
From:	Gerry Houlder <gerry.houlder at seagate.com>
To:	T10 Reflector <t10 at t10.org>, 
Date:	06/06/2014 08:21 AM
Subject:	Re: Download microcode proposals
Sent by:	<owner-t10 at t10.org>
Hi Bill,
I reviewed 14-150r0 and 14-121r1 and have these comments:
(a) The text in 14-150r0 lumps download options 07h and 0Eh in with option 
0Dh in describing the error case. This is incorrect. Options 07h and 0Eh 
always requires the MODE SPECIFIC field to be zero (i.e., the field is 
reserved) just like all of the other download options, so these cases 
should always result in ILLEGAL REQUEST sense key with INVALID FIELD IN 
CDB additional sense if that field is ever non-zero.
(b) I verified that Seagate products remember the MODE SPECIFIC field 
setting (for option 0Dh) on the first download command in a sequence 
(i.e., when the BUFFER OFFSET is zero) and expect further download 
commands in the same sequence to match that MODE SPECIFIC setting. If a 
further command doesn't match the MODE SPECIFIC setting, then the command 
is rejected with ILLEGAL REQUEST sense key and INVALID FIELD IN CDB 
additional sense code.
Seagate prefers using ILLEGAL REQUEST sense data to indicate that the 
command is being discarded but any previously accepted download segments 
are preserved, meaning that a correct download command resuming the 
sequence is all that is needed for recovery. In most of the cases when 
COMMAND SEQUENCE ERROR is reported, Seagate drives discard any previously 
received download segments and expect the initiator to start over again 
|from the beginning.
(c) Since the error situation described in 14-150 should only occur in 
download option 0Dh (all other cases are covered by our existing rule 
about reserved fields), then i prefer  error code response description to 
be in the location indicated in proposal 14-121r1, not in the location 
indicated in 14-150.
On Thu, Jun 5, 2014 at 4:10 PM, Bill Martin-SSI <
bill.martin at ssi.samsung.com> wrote:
As you may remember, I presented a proposed clarification of download 
microcode at the last T10 plenary meeting week. This was 14-121r1. There 
was agreement to review what products are currently doing in the case 
described.
I have posted another proposal 14-150r0 with some additional 
clarifications to the download microcode operation. Please review this 
proposal to determine what your products currently do, so that we may 
complete these actions at the T10 plenary meeting in July in Colorado 
Springs.
Thanks,
Bill Martin
SSD I/O Standards 
Samsung Semiconductor, Inc. 
Cell (408) 499-1839



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