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

Robert Snively rsnively at Brocade.COM
Tue Nov 14 14:25:30 PST 2000


*
* 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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