FCP-2 correction of incomplete statement required. Please review!

Baldwin, Dave Dave.Baldwin at emulex.com
Tue Nov 14 18:05:16 PST 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* "Baldwin, Dave" <Dave.Baldwin at emulex.com>
*
Bob,

How about something a little more specific:

If the amount of data

add:>bytes<

returned does not match

        (delete: FCP_DL,)

 add:>FCP_DL minus FCP_RESID, <

        the error detection and recovery procedure described
        in clause 12 may be invoked or the FCP I/O operation
        may be terminated with a recovery abort or other failure
        indication. The mechanism an initiator uses to determine
        that the correct amount of data has been returned is
        vendor specific. Data that has been retransmitted and
        overlaid shall be counted only once for the purposes of
        calculating residual values.

Best regards,
Dave Baldwin
Emulex Corporation


Robert Snively wrote:

> *
> * From the fc reflector, posted by:
> * Robert Snively <rsnively at Brocade.COM>
> *
> While performing the final proof reading of FCP-2 and preparing
> the bi-directional data transfer annex, I found the following
> discrepancy in clause 9.3 which I believe should be corrected.
>
> The next to the last paragraph says:
>
>         If the amount of data returned does not match FCP_DL,
>         the error detection and recovery procedure described
>         in clause 12 may be invoked or the FCP I/O operation
>         may be terminated with a recovery abort or other failure
>         indication. The mechanism an initiator uses to determine
>         that the correct amount of data has been returned is
>         vendor specific. Data that has been retransmitted and
>         overlaid shall be counted only once for the purposes of
>         calculating residual values.
>
> This is really not correct unless the device was expected to
> transfer FCP_DL amount of data and terminated early
> because of a link error.  More normally, FCP_DL will not
> be the amount of data transferred and an appropriate FCP_RSP
> will be provided with a CHECK CONDITION/INCORRECT LENGTH
> or with an appropriate overrun or underrun and a proper residual.
> In those cases, normal operation continues, with a corrected
> data count calculated from the residual information.
>
> I propose that the last paragraph be modified to read:
>
>         If the amount of data returned does not match
>
>         (delete: FCP_DL,)
>
>  add:>the number of bytes of data calculated from the
>         value of FCP_DL and the value of FCP_RESID, if any,<
>
>         the error detection and recovery procedure described
>         in clause 12 may be invoked or the FCP I/O operation
>         may be terminated with a recovery abort or other failure
>         indication. The mechanism an initiator uses to determine
>         that the correct amount of data has been returned is
>         vendor specific. Data that has been retransmitted and
>         overlaid shall be counted only once for the purposes of
>         calculating residual values.
>
> Is this okay with everybody?
>
> Bob Snively                        e-mail:    rsnively at brocade.com
> Brocade Communications Systems     phone:  408 487 8135
> 1745 Technology Drive
> San Jose, CA 95110

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