SAS SMP function results - comment resolutions

Elliott, Robert (Server Storage) Elliott at hp.com
Wed Jan 29 16:42:06 PST 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
*
While merging the SMP function result codes per 03-058r0, it became
apparent that several of them make no sense and need to be changed or
deleted.  Here are the changes I'm planning for sas-r03c:


PHY CONTROL function results (see 10.3.1.9)
============================
OTHER ERROR - no explanation is given for why this would be used.
Suggestion: remove it.

PHY OPERATION FAILED - We don't want the SMP connection to stay open
while the SMP target tries to run any of the selected operations (e.g.
link reset).  They should all complete immediately, spawning a
background task if needed.  None of the operations should "fail." 
Suggestion: remove it.

UNKNOWN PHY OPERATION - if this occurs, what happens to writing the
programmed minimum/maximum physical link rate fields and the PPTV field?
Suggestion: if this occurs, do NOT update any fields.


REPORT PHY SATA function results (see 10.3.1.6)
================================

PHY NOT SATA - software can tell the phy is not current in a usable SATA
mode by inspecting byte 0 of the REGISTER DEVICE TO HOST FIS field.
DISCOVER also provides detailed information about the phy status.
Suggestion: remove it.

SATA RESET HALTED - the negotiated physical link rate field in DISCOVER
now reports the SATA spinup hold condition, so this is unnecessary.
Suggestion: remove it


Are (invalid) data bytes still returned with non-zero function results?
=======================================================================
Currently, codes 01h and 02h (see 9.4.3) claim the ADDITIONAL RESPONSE
BYTES field is not present.  Codes 10h+ imply the field is present, but
usually label it as having invalid contents.

Suggestion: make all the non-zero codes work the same - the additional
response bytes field may be present but shall be ignored.  The SMP
target can truncate it if it wants, or it can always return data.
Either way, the SMP initiator must ignore it.

Compact the codes
=================
Since 03-058r0 was renumbering the codes anyway, we might as well pack
them down.


Suggestion:
00h SMP FUNCTION ACCEPTED
01h UNKNOWN SMP FUNCTION
02h SMP FUNCTION FAILED
10h PHY DOES NOT EXIST
11h INDEX DOES NOT EXIST
12h PHY DOES NOT SUPPORT SATA
13h UNKNOWN PHY OPERATION

The 00h-0Fh range applies to "all functions" - the rest only apply to
certain functions.


--
Rob Elliott, elliott at hp.com
Hewlett-Packard Industry Standard Server Storage Advanced Technology
https://ecardfile.com/id/RobElliott



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