[T10] ATA PASS-THROUGH(32) straw poll

John Geldman (jgeldman) jgeldman at micron.com
Mon Nov 16 20:01:31 PST 2015


Neil,

It may be late and I may be intellectually lazy tonight, but that is the most convoluted presentation of material that I've seen in a while. It takes more effort than I can muster this evening to visualize each two page table and mentally find the differences.

The attached spreadsheet is an easier way to look. (Now I see the SCSI-friendly version has the fields in contiguous order, while the SATA-friendly version has the fields in all master/all slave order).

The attached does also reveal that your 2nd and 3rd table have a Control (7:0) field that doesn't exist in the first table. 

While I fixed inconsistent names, explaining the 'odd' Control field is up to you (I think it is a duplicate of the SCSI field). 

Grumpily yours,
John


-----Original Message-----
From: t10-bounces at t10.org [mailto:t10-bounces at t10.org] On Behalf Of Neil Wanamaker
Sent: Monday, November 16, 2015 6:57 PM
To: t10 at t10.org
Cc: nathan seiler; terry.denney at hpe.com
Subject: [T10] ATA PASS-THROUGH(32) straw poll

All:

At the recent T10 CAP meeting, Gerry Houlder presented 15-269r0, which included a new ATA PASS-THROUGH(32) command. In his proposal, he made the CDB structure consistent with the form of the ATA PASS-THROUGH(16), adding AUX and ICC at the end. 

In general, I applaud consistency, but... the ATA PASS-THROUGH(16) command seems to have few redeeming features - it is neither convenient for the SCSI initiator or for the SATL, what with the LBAs being scrambled, etc.

To make the new command convenient for either the initiator or the SATL, I would like feedback on which of the three formats in the attachment would be preferable.

The first is Gerry's proposal unchanged apart from using a service action of the form xx00, as the SPC editor suggests reserving a block of service actions (such as 3000h-37ffh)for SAT, as shown in Table E.8 of SPC-5. 

The second is a SCSI-friendly structure, putting LBA and AUX in big-endian form aligned to appropriate boundaries. I have added the CONTROL(7:0) field (which could be added to the first proposal, if people wanted to go that route. 

The third is a SAT (or ATA if you prefer) - friendly structure, which may be familiar to some of you. 

I would appreciate feedback from the audience as to which of these best meets your needs. 

Best regards,
Neil Wanamaker
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Neil's ATA PassThrough Revisited.xlsx
Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
Size: 10196 bytes
Desc: Neil's ATA PassThrough Revisited.xlsx
URL: <http://www.t10.org/pipermail/t10/attachments/20151117/e1f9447b/attachment.xlsx>


More information about the T10 mailing list