Draft Minutes of SAS Protocol WG - August 21-23, 2002

John Lohmeyer lohmeyer at t10.org
Fri Aug 23 09:00:19 PDT 2002


* From the T10 Reflector (t10 at t10.org), posted by:
* John Lohmeyer <lohmeyer at t10.org>
*
A PDF of these minutes is available at:

   ftp://ftp.t10.org/t10/document.02/02-322r0.pdf


Accredited Standards Committee*
InterNational Committee for Information Technology Standards (INCITS)

                                                     Doc. No.: T10/02-322r0
                                                         Date: August 23, 2002
                                                     Reply to: John Lohmeyer
To:      T10 Membership
From:    John Lohmeyer
Subject: SAS Protocol Working Group -- August 21-23, 2002

Agenda
1.     Opening Remarks
2.     Approval of Agenda
3.     Attendance and Membership
4.     Old Business
4.1      SAS Working Draft Review [Elliott]
4.2      SAS Port Control State Diagram Update (02-202) [Worden]
4.3      SAS COMMAND ID Removal (02-259) [Day]
4.4      Initiator based discovery and configuration of the SAS topology,
proposal (02-279) [Fairchild]
4.5      Arbitration clarification (02-222) [Galloway]
4.6      SAS SSP target transport layer state machines (02-287) [Evans]
4.7      SAS - OOB and DWS state machines update (02-300) [Grieff]
4.8      SAS Combined Request-Configuration List (02-276) [Worden]
4.9      Rate Change Delay in speed negotiation window [Grieff]
4.10     AEN on SAS (02-196) [Penokie]
5.     New Business
5.1      SAS SSP transport layer state machines (02-307) [Mark Evans]
5.2      SAS Data Transfer Rules (02-318) [Gardner]
5.3      SAS Relative Offset (02-319) [Gardner]
5.4      SAS Simplified Arbitration (02-320) [Gardner]
5.5      SAS Data Corruption Problem (02-323) [Gardner]
6.     Review of Recommendations to the Plenary
7.     Meeting Schedule
8.     Adjournment


Results of Meeting

1.     Opening Remarks

John Lohmeyer called the meeting to order at 9:00 a.m., Wednesday, August 21,
2002. He thanked Mark Evans of Maxtor for hosting the meeting.


2.     Approval of Agenda

The draft agenda was approved with the following changes:

5.3      SAS Relative Offset (02-319) [Gardner]

The following items were added/revised during the course of the meeting:

5.4      SAS Simplified Arbitration (02-320) [Gardner]
5.5      SAS Data Corruption Problem (02-323) [Gardner]


3.     Attendance and Membership

Attendance at working group meetings does not count toward minimum attendance
requirements for T10 membership. Working group meetings are open to any person
or organization directly and materially affected by T10's scope of work. The
following people attended the meeting:

          Name          S        Organization         Electronic Mail Address
---------------------- -- ------------------------- -------------------------
Mr. Mike Fitzpatrick   P  Fujitsu                   mfitzpatrick at fcpa.
                                                     fujitsu.com
Mr. Rob Elliott        P  Hewlett Packard Co.       Elliott at hp.com
Mr. Steven Fairchild   V  Hewlett Packard Co.       Steve.Fairchild at hp.com
Mr. Joe Vincent        V  Hitachi America           joe.vincent at hal.hitachi.
                                                     com
Mr. Steven Wirtz       V  I-TECH Corp.              steve_wirtz at i-tech.com
Mr. George O. Penokie  P  IBM / Tivoli Systems      gop at us.ibm.com
Mr. John Lohmeyer      P  LSI Logic Corp.           lohmeyer at t10.org
Mr. Brian Day          V  LSI Logic Corp.           brian.day at lsil.com
Mr. Tim Hoglund        V  LSI Logic Corp.           tim.hoglund at lsil.com
Mr. Jeffrey Rogers     V  LSI Logic Corp.           jeff.rogers at lsil.com
Mr. Mark Evans         P  Maxtor Corp.              mark_evans at maxtor.com
Mr. Steve Byan         V  Maxtor Corp.              stephen_byan at maxtor.com
Mr. David Cressman     V  Maxtor Corp.              dave_cressman at maxtor.com
Mr. Martin Czekalski   V  Maxtor Corp.              marty_czekalski at maxtor.
                                                     com
Mr. David Griffith     V  Maxtor Corp.              dave_griffith at maxtor.com
Mr. Edward A. Gardner  P  Ophidian Designs          eag at ophidian.com
Mr. Arie Krantz        V  QLogic Corp.              l_krantz at qlc.com
Mr. Jim Coomes         V  Seagate Technology        jim_coomes at seagate.com
Mr. John Worden        V  Seagate Technology        john.worden at seagate.com

19 People Present

Status Key:  P    -  Principal
              A,A# -  Alternate
              AV   -  Advisory Member
              L    -  Liaison
              V    -  Visitor


4.     Old Business

4.1    SAS Working Draft Review [Elliott]

Rob Elliott presented SAS-R01.

Ed Gardner asked several questions of the group relative to SSP data transfers
and error handling:

Q. With a bi-directional command, can the data-in and data-out transfers
proceed concurrently? E.g. can a target send XFER_RDY, then send DATA frames
for the data-in transfer without waiting for all DATA frames for the data-out
transfer to arrive?
A. Yes, provided the definition of the command does not require the data-in
and data-out transfers to be performed in a specific order.

Q. Has any thought been given whether data striping might be allowed or
required in SAS-2? Data striping means transferring data for a single command
(in a single direction) simultaneously on multiple connections.
A. There are no plans to include this in SAS-2.

Q. When an initiator issues a task management function that aborts one or more
commands, who is responsible for terminating any XFER_RDYs that may be
outstanding for those commands?
A. The initiator is expected to terminate data transfer for any XFER_RDYs for
the affected commands before it issues the task management function.

Q. When an initiator encounters a failure transmitting a DATA frame (data-out
transfer), how is the error communicated to the target?
A. The initiator may continue or abandon the data-out transfer. The target
will detect that insufficient data has been delivered after a timeout (unless
the initiator issues a TASK ABORT).

Jim Coomes and Mark Evans agreed to prepare a proposal to report SAS
transmission errors. This may include SMP, mode pages, and/or log pages.

George Penokie presented an email he had received identifying an issue if a
target detects an error while there is an outstanding transfer ready. The
group proposed that a rule be added that the target shall not send the
response frame until all data associated with the XFER_RDY have been received.

George Penokie moved that it be recommended that SAS be modified to require
targets to not send a response frame for a command until all data associated
with any outstanding XFER_RDY for that command have been received. John
Lohmeyer seconded the motion. The motion passed 6:0:0.

George presented a second email identifying a conflict between figure 16 and
the link rate field definition on page 111. The conflict was viewed as
editorial and Rob Eliiott agreed to correct the link rate definition.

George Penokie moved that it be recommended that the open originator shall
start rate matching on the next dword after the OPEN address frame has been
transmitted. John Lohmeyer seconded the motion. The motion passed 7:0:0.

4.2    SAS Port Control State Diagram Update (02-202) [Worden]

John Worden reviewed 02-202r2, SAS Port Control State Diagram Update. He
received extensive input and agreed to prepare a revision 3. Later in the
meeting, John presented updated state diagrams and received tentative
approval.

George Penokie noted that an initiator with a wide port consisting of four
physical links connected to four narrow targets can have four concurrent
connections with each of the four targets. Wording in the SAS working draft
may need revision to make this concept clear. George agreed to prepare a
proposal.

4.3    SAS COMMAND ID Removal (02-259) [Day]

Brian Day presented 02-259r1, SAS COMMAND ID Removal. The group was in general
agreement with removing the COMMAND ID, but the detailed impacts on the
transport state machine need to be fleshed out.

Brian Day moved that 02-259r1 be recommended for inclusion in SAS. Jim Coomes
seconded the motion. There was some discussion about the effect of the motion.
It was noted that the only changes to SAS at this point would be:

o      Remove the field from section 9.2.1 Frame Format
o      Remove the words "(based on the COMMAND_ID field and the I_T_L_Q),"
|from section 9.2.5.4

The motion passed 8:0:1.

Brian agreed to talk to Mark Evans and John Worden about any other impacts of
allowing his implementation and to write another proposal if necessary. It was
noted that there may be a few more instances of references to COMMAND ID that
also need to be expunged.

4.4    Initiator based discovery and configuration of the SAS topology,
proposal (02-279) [Fairchild]

Steve Fairchild presented 02-279r3, Initiator based discovery and
configuration of the SAS topology. He reviewed the changes, received input,
and agreed to prepare a revision 4.

Steve Fairchild moved that 02-279r4 (r3 as revised) (changes 1 through 13) be
recommended for inclusion into SAS. Tim Hoglund seconded the motion. The
motion passed 8:0:0.

4.5    Arbitration clarification (02-222) [Galloway]

In the absence of Bill Galloway, this topic was deferred.

4.6    SAS SSP target transport layer state machines (02-287) [Evans]

Mark Evans asked that this item be dropped as the target transport state
diagram is included in 02-307.

4.7    SAS - OOB and DWS state machines update (02-300) [Grieff]

In the absence of Tom Grieff, this topic was deferred.

4.8    SAS Combined Request-Configuration List (02-276) [Worden]

John Worden presented 02-276r1, SAS Combined Request-Configuration List. He
received input and agreed to prepare a revision 2.

4.9    Rate Change Delay in speed negotiation window [Grieff]

In the absence of Tom Grieff, this topic was deferred.

4.10   AEN on SAS (02-196) [Penokie]

Based on the input from the July CAP and T10 meetings, Mark Evans moved that
it be recommended that AEN be removed from SAS. George Penokie seconded the
motion. The motion passed 8:0:1.


5.     New Business

5.1    SAS SSP transport layer state machines (02-307) [Mark Evans]

Mark Evans presented 02-307r0, SAS SSP transport layer state machine. This
document includes 02-287, SAS SSP target transport layer state machines. Mark
received input and agreed to prepare a revision 1.

5.2    SAS Data Transfer Rules (02-318) [Gardner]

Ed Gardner presented 02-318r0, SAS Data Transfer Rules. The proposal would add
additional restrictions to the data transfer rules and improve wording in a
number of places. Mark Evans agreed to make several of the wording
improvements in sub-clause 9.2. The overall proposal was deferred to the
September meeting to get a wider review.

5.3    SAS Relative Offset (02-319) [Gardner]

Ed Gardner presented 02-319r0, SAS Relative Offset. This proposal would add an
optional relative offset function to SAS. Ed received input and agreed to
revise his proposal.

5.4    SAS Simplified Arbitration (02-320) [Gardner]

Ed Gardner presented 02-320r0, SAS Simplified Arbitration. The scheme uses a
hierarchical structure that Ed claims is guaranteed to be deadlock free and
simpler than today's method. It is extensible to larger topologies that
currently supported.

Ed noted that he feels there are legitimate intellectual property claims in
his proposal, but he does not plan to pursue these claims. Should he obtain
such claims, he would be willing to comply with the ANSI patent policy.

There were concerns that changing direction now would impact schedules.

5.5    SAS Data Corruption Problem (02-323) [Gardner]

Ed Gardner presented 02-323r0, SAS Data Corruption Problem. There was debate
whether or not the case Ed describes is `corruption' or not. Mark Evans noted
that he was adamantly opposed to any of Ed's proposed solutions.

The topic was deferred.


6.     Review of Recommendations to the Plenary

John Lohmeyer noted that the following recommendations have been made to the
T10 plenary:

that it be recommended that SAS be modified to require targets to not send a
response frame for a command until all data associated with any outstanding
XFER_RDY for that command have been received.
that it be recommended that the open originator shall start rate matching on
the next dword after the OPEN address frame has been transmitted.
that 02-259r1 be recommended for inclusion in SAS.
that 02-279r4 (r3 as revised) (changes 1 through 13) be recommended for
inclusion into SAS.
that it be recommended that AEN be removed from SAS.


7.     Meeting Schedule

SAS Protocol Working Group meetings are scheduled for:

Monday-Tuesday, September 9-10, 2002 commencing at 1:00 p.m. on Monday and
ending at 5:00 p.m. on Tuesday in Minneapolis, MN at the Hilton
Minneapolis/St. Paul Airport Hotel (952-854-2100).

Monday-Tuesday, November 4-5, 2002 commencing at 1:00 p.m. on Monday and
ending at 5:00 p.m. on Tuesday in Huntington Beach, CA at the Hilton
Waterfront Hotel (714-960-7873).

A SAS STP Issues Study Group meeting is tentatively scheduled for Wednesday,
September 11, 2002 beginning at 9:00 a.m. and ending at noon. This meeting
will be chaired by Ron Roberts and the intent is to identify any issues with
the STP protocol.

George Penokie agreed to host a SAS Protocol teleconference:

    Tuesday September 3, 2002
    11:00 am -- 2:00 pm  EDT
    10:00 am -- 1:00 pm  CDT
     9:00 am -- noon     MDT
     8:00 am -- 11:00 am PDT

    USA Toll Free Number: 877-921-6914
             Toll Number: +1-712-923-0332
    Participant Passcode: 338024

WebEx Session: http://seagate.webex.com/
  Meeting Name: SAS Protocol teleconference
      Password: Carol18

It is likely that there will be another SAS protocol teleconference call on
September 24th, but the need will be determined at the September working group
meeting.

An editing meeting is tentatively planned for October 3-4, 2002 in Houston,
TX.


8.     Adjournment

The meeting was adjourned at approximately noon on Friday, August 23, 2002.

--
John Lohmeyer                  Email: lohmeyer at t10.org
LSI Logic Corp.                Voice: +1-719-533-7560
4420 ArrowsWest Dr.              Fax: +1-719-533-7183
Colo Spgs, CO 80907

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