MAINTENANCE IN/OUT Commands in SPC-2

Ralph Weber ralphoweber at CompuServe.COM
Sat Dec 30 19:47:14 PST 2000


* From the T10 Reflector (t10 at t10.org), posted by:
* Ralph Weber <ralphoweber at compuserve.com>
*
In the SPC-2 letter ballot, a total of five comments from
three companies raise issues around the description of
the two MAINTENANCE IN/OUT commands that have been "general-
ized" in SPC-2 (the REPORT DEVICE IDENTIFIER and SET DEVICE
IDENTIFIER commands).

In the upcoming SPC-2 letter comments resolutions document
revision, I will propose the following changes.  Issues and
ideas for improvements are solicited.

For REPORT DEVICE IDENTIFIER
============================

Comment 8.104 [581] Seagate 103) suggests "…is applicable to…"
which strikes the editor as more wordy way of saying "…applies to…".
Comment 7.76 [460] Quantum 76) raises concerns about whether this
wording implies a requirement to implement.  Looking forward to
SPC-3, other MAINTENANCE IN/OUT service actions will be defined
with implementations allowed by any device type.  In order to avoid
having to re-rewrite this sentence in SPC-3 and in order to have
consistency between the "set" and "report" descriptions (and
noting the issue raised by comment style comments, e.g. "SCCS bit
set to one" not just "set") the text in this area will be rewritten.

Note that the addition of "and MAINTENANCE OUT" in the rewritten
last sentence of the first paragraph is a hack that avoids
incorrectly saying that SPC-2 defines other MAINTENANCE IN
service actions.  In SPC-3 those three words probably can be
deleted.

The proposal is to change the text from:

This command is optional for all device types, except for SCC-2
devices, and devices that set the SCCS bit in their Standard Inquiry
data (see 7.6.2).  As defined in the SCC-2 standard, the REPORT
DEVICE IDENTIFIER command is the REPORT PERIPHERAL DEVICE/COMPONENT
DEVICE IDENTIFIER service action of the MAINTENANCE IN command.
Additional MAINTENANCE IN service actions (that apply to SCC-2
devices and devices that set the SCCS bit in their Standard Inquiry
data) are defined in SCC-2. Only the REPORT DEVICE IDENTIFIER
operation code and service action concerns all SCSI devices.

to:

As defined in the SCC-2 standard, the REPORT DEVICE IDENTIFIER
command is the REPORT PERIPHERAL DEVICE/COMPONENT DEVICE IDENTIFIER
service action of the MAINTENANCE IN command.  Additional MAINTENANCE
IN and MAINTENANCE OUT service actions are defined in SCC-2 and in
this standard.

The MAINTENANCE IN service actions defined only in SCC-2 shall apply
only to SCSI devices that return a device type of 0Ch or the SCCS bit
equal to one in their standard INQUIRY data.  When a SCSI devices
returns a device type of 0Ch or the SCCS bit equal to one in its
standard INQUIRY data, the implementation requirements for the SCC-2
MAINTENANCE IN service actions shall be as specified in SCC-2.
Otherwise the MAINTENANCE IN service action definitions and
implementation requirements stated in this standard shall apply.

For SET DEVICE IDENTIFIER
=========================

All the discussion from REPORT DEVICE IDENTIFIER still applies and
the it is proposed that the text be changed from:

This command is optional for all device types.  As defined in the
SCC-2 standard, the SET DEVICE IDENTIFIER command is the SET
PERIPHERAL DEVICE/COMPONENT DEVICE IDENTIFIER service action of
the MAINTENANCE OUT command.  Additional MAINTENANCE OUT service
actions are defined in SCC-2.  Only the SET DEVICE IDENTIFIER
operation code and service action concerns all SCSI devices.

to:

As defined in the SCC-2 standard, the SET DEVICE IDENTIFIER
command is the SET PERIPHERAL DEVICE/COMPONENT DEVICE IDENTIFIER
service action of the MAINTENANCE OUT command.  Additional MAINTENANCE
IN and MAINTENANCE OUT service actions are defined in SCC-2 and in
this standard.

The MAINTENANCE OUT service actions defined only in SCC-2 shall apply
only to SCSI devices that return a device type of 0Ch or the SCCS bit
equal to one in their standard INQUIRY data.  When a SCSI devices
returns a device type of 0Ch or the SCCS bit equal to one in its
standard INQUIRY data, the implementation requirements for the SCC-2
MAINTENANCE OUT service actions shall be as specified in SCC-2.
Otherwise the MAINTENANCE OUT service action definitions and
implementation requirements stated in this standard shall apply.

Thanks.

Ralph...



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