Late letter ballot comment on REPORT SUPPORTED OPERATION CODES command

[Gerry Houlder]

Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1207300_f.htm">HTML-formatted message</a>

Hi Ralph and others,
It has been pointed out that there is an error case where the expected
response of the device server is not clear. I would like to add some words
to clarify the case.
The problem:
(a) The One_command data format includes a SUPPORT field. One of the
possible values for this field indicates the command is not supported. This
provides a strong preference for reporting unsupported commands when the
One_command format is specified by returning data with the SUPPORT field
set to "unsupported" and completing the command with GOOD status.
(b) Table 295 describes the reporting for REPORTING OPTIONS type 010b as
"If the REQUESTED OPERATION CODE CDB field specifies an operation code that
does not have service actions, then the command shall be terminated with
CHECK CONDITION status, ..". Type 001b has similar wording.
The possible conflict occurs when a command with REPORTING OPTIONS set to
010b specifies an unsupported command. It is unrealistic to expect a device
server to understand whether the operation code has a service action field
or not when the operation code is unsupported, so the unsupported operation
code case needs to be an exception for reporting the CHECK CONDITION status.
I would like to see the wording in Table 295 for the 010b case changed as
follows:
<<added text>>
The command support data for the operation code and service action a
specified in the REQUESTED OPERATION CODE CDB field and REQUESTED
SERVICE ACTION CDB field shall be returned in the one_command
parameter data format. If the REQUESTED OPERATION CODE CDB field
specifies an operation code that <<is supported and>> does not have service
actions, then the
command shall be terminated with CHECK CONDITION status, with the
sense key set to ILLEGAL REQUEST, and the additional sense code set
to INVALID FIELD IN CDB.
The same idea applies to the wording in Table 295 for the 001b case as well:
<<added text>>
The command support data for the operation code specified in the
REQUESTED OPERATION CODE field shall be returned in the one_command
parameter data format. The REQUESTED SERVICE ACTION CDB field shall be
ignored. If the REQUESTED OPERATION CODE field specifies an operation
code that <<is supported and>> has service actions, then the command shall
be terminated
with CHECK CONDITION status, with the sense key set to ILLEGAL
REQUEST, and the additional sense code set to INVALID FIELD IN CDB.