MODE SELECT SP bit question

Kevin D Butt kdbutt at us.ibm.com
Fri Jan 28 09:01:07 PST 2011


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All,
I was just surprised by one of my engineers telling me that the SP bit in 
the MODE SELECT command set to one indicates that ALL saveable mode 
parameters - not just those sent in this MODE SELECT command - are 
supposed to be saved.  I thought it meant to save the saveable parameters 
of those sent in this MODE SELECT command.  The text in SPC-4r29 states:
<<An SP bit set to one specifies that the device server shall perform the 
specified MODE SELECT operation, and shall save
to a nonvolatile vendor specific location all the saveable mode pages 
including any sent in the Data-Out Buffer.>>
When I read this, I see the "including any sent in the Data-Out Buffer" 
and I have to conclude that my engineer is correct.
Are we interpreting this correctly and should this be made more clear?
Potential clarification
<<An SP bit set to one specifies that the device server shall perform the 
specified MODE SELECT operation, and shall save
to a nonvolatile vendor specific location all the saveable mode pages sent 
in the Data-Out Buffer and not sent in the Data-Out Buffer.>>
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
Data Protection & Retention
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt at us.ibm.com



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