03-002r0: Remove SPI from SAM-3 and SPC-3 [a little bit more]

Ralph Weber ralphoweber at compuserve.com
Tue Jan 7 19:30:58 PST 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* Ralph Weber <ralphoweber at compuserve.com>
*
Rob,

I never suggested that REQUEST SENSE be made obsolete.
I am, however, questioning whether it needs to remain
mandatory for all device types.

I seriously doubt that any real world device will decline
to implement REQUEST SENSE anytime soon.

I do not have any serious problems with leaving REQUEST
SENSE mandatory for all device types, but I believe that
the result will be a profoundly lame explanation of why
in SPC-3 subclause 5.2.3 along the lines of the polling
function that you note.

This could be a case where we decide to make no changes
now and let time give us some perspective on the matter.
That is a fine way to go.

Regards,

.Ralph

Elliott, Robert (Server Storage) wrote:

> 
>* From the T10 Reflector (t10 at t10.org), posted by:
>* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
>*
>There is one other SCSI transport that still uses contingent allegiance
>(CA): ATAPI (ATA Packet Interface, defined in T13's ATA/ATAPI standard).
>ATAPI devices will still require REQUEST SENSE, regardless of their
>command set (most likely but not exclusively MMC).  Perhaps that
>requirement could be documented in ATA/ATAPI-7 itself. 
>
>Many devices let applications poll with REQUEST SENSE to retrieve sense
>data containing progress indication - the status of long operations like
>FORMAT MEDIUM or self-test.  I don't think autosense can replace this
>usage.  REQUEST SENSE might only need to be required for devices
>implementing those commands, though.
>
>A quick web search shows at least one Fibre Channel driver might get
>upset if a target chose not to support autosense (but only after it had
>trouble delivering the autosense data in the first place):
>"The driver now issues a request sense when an FCP_RSP is received with
>check condition status, but no sense data (CR#3872)"
>
>--
>Rob Elliott, elliott at hp.com
>Hewlett-Packard Industry Standard Server Storage Advanced Technology
>https://ecardfile.com/id/RobElliott
>  
>


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