Vendor-Specific Mode Subpages

Ralph Weber roweber at
Mon Jan 24 15:56:41 PST 2011

* From the T10 Reflector (t10 at, posted by:
* Ralph Weber <roweber at>
I signed out a document number to deal with these issues
(and others) but never found the time to write it:
10-389r0 - (Ralph Weber) Truth and Reconciliation for SPC-4 page codes
I had an "interesting" debating point (which Gerry has shot full of
holes). It went something like this. Whomever wrote the Mode Subpages
proposal saw fit to allows requests to be sent for VS mode pages,
but failed to allow device servers to return them. Such is the nature
of the difference between the two tables cited in Paul's original
I will gladly work on posting 10-389r0 in my copious spare time, or
hand the upload code over to someone with more time to fix the bug.
All the best,
On 1/24/2011 5:21 PM, Gerry Houlder wrote:
> I am aware of some vendor specific sub-pages in the E0h to EFh range 
> for mode page 19h for SAS protocol specific use. I have to support the 
> use of these mode page 19h sub-pages for vendor specific use. I don't 
> see any harm in extending this "privilege" to other standard pages as 
> well to simplify the documentation (i.e., not make mode page 19h a 
> glaring exception to the rule).
> I am surprised that we have two tables (164 and 398) that apparently 
> have the same purpose (i.e., indicating which mode pages and sub-pages 
> are standard/ restricted/ vendor specific). It would be more logical 
> to do this in one table, to prevent the conflicts you have discovered. 
> The table 398 structure seems more suited to providing all of the 
> needed details.
> On Mon, Jan 24, 2011 at 4:17 PM, Paul Suhler <Paul.Suhler at 
> > wrote:
>     Hi, everyone.
>     Curtis Ballard and I were discussing SPC-4's conflicting
>     statements about whether every mode page has a vendor-specific
>     range of subpage codes.  His analysis is:
>	  MODE SELECT(6) has a table for mode page codes for all devices
>	  (table 164) which lists sub_pages E0h to FEh as vendor
>	  specific for every page except 3Fh.  For  the page range 20h
>	  to 3Eh even more sub_pages are vendor specific.
>	  But if you look at the tables in the mode parameters section
>	  those ranges say "see specific device type".
>     That refers to Table 398, which conflicts with Table 164 for page
>     codes 02h, 09h,15h, and 16h.  (164 says to see the device
>     standard; 398 says they're reserved.)  I don't recall the details
>     of the discussion in CAP about this.
>     Changes would be needed to (at least) Table 398 and to various
>     device standards (SSC-4 and ADC-3, for starters).
>     So, I'd first like to get the sense of the group:  Does anyone
>     *not* want a vendor subpage range available for most mode pages? 
>     (We can sort out which specific pages shall not have this range.)
>     Thanks,
>     Paul
>     Paul A. Suhler| Firmware Engineer | Quantum Corporation| Office:
>     949.856.7748 | paul.suhler at
>     *Preserving the World's Most Important Data. Yours.™*
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