USB Mass storage sub-class for MMC devices

plavarre at lexar.com plavarre at lexar.com
Thu Sep 20 17:16:38 PDT 2007


* From the T10 Reflector (t10 at t10.org), posted by:
* <plavarre at lexar.com>
*
Eh?? How so?
We can't redefine an assigned code, seven years after the fact.
No?
Redefining that code would break hosts built to the old definition?
Right?
No can do?
Most curiously yours, thanks in advance, Pat LaVarre
P.S. Microsoft has published definitions of three of the USB Mass Storage
bInterfaceSubClass codes (specifically h 06 05 02) at Whdc. I don't see much
point in trying to contradict the de facto reality of those definitions,
massively distributed as binary thru ME 2K XP Vista etc. Windows, with de
jure paper theories published elsewhere.
P.P.S. I admit I am speaking as the person who invented code 06h for the
express purposes of obsoleting all the others, which were assigned before I
arrived on the scene, for no reasonable purpose I was ever able to persuade
anyone to identify in writing. I think that field should have been left at
00h for the use later by such open standard efforts as:
""" Lockable Mass Storage
Lockable Mass Storage is tasked with creating a specification that allows
users to lock their mass storage device so that the data stored on it will
not be vulnerable in the event the device is lost or stolen.
This feature specification extends the USB Mass Storage class to allow hosts
and devices to lock and unlock storage, without breaking the legacy host
behavior that exists today and without resorting to vendor-specific
descriptors and requests.
DWG Members may join this group only after executing the IP Agreement
corresponding to the specification under development by this group. 
""" http://www.usb.org/about/dwg_charter/
P.P.P.S. Happy Thursday. Not only am I here writing SCSI thru USB e-mail
again, but I've been feeding a Wiki Blog too:
http://members.aol.com/ppaatt/#%5B%5BHippy%20Wikis%5D%5D%20TiddlyWiki
-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Curtis
Stevens
Sent: Thursday, September 20, 2007 4:16 PM
To: Bill McFerrin; t10 at t10.org; Mt.Fuji
Subject: RE: USB Mass storage sub-class for MMC devices
* From the T10 Reflector (t10 at t10.org), posted by:
* "Curtis Stevens" <curtis.stevens at wdc.com>
*
An alternative would be to change subclass 02h to say MMC-2 and above...
 
 
-------------------------------------------------
Curtis E. Stevens
20511 Lake Forest Drive #C-214D
Lake Forest, California 92630
Phone: 949-672-7933
Cell: 949-307-5050
E-Mail: Curtis.Stevens at WDC.com
-----Original Message-----
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of Bill McFerrin
Sent: Thursday, September 20, 2007 2:15 PM
To: t10 at t10.org; Mt.Fuji
Subject: USB Mass storage sub-class for MMC devices
* From the T10 Reflector (t10 at t10.org), posted by:
* Bill McFerrin <billmc37 at ctesc.net>
*
Members:
Curtis Stevens (Western Digital) came to our MMC WG meeting on 19 September
2007 to bring up a concern about UBC mass storage bridge implementations.
The drive sub-class may be specified as either
SFF8020/MMC-2 (value = 2) or Transparent SCSI (value=6). Since SFF8020 is
obsolete and MMC-2 has been withdrawn as a standard, we should act to promote
the use of only drive sub-type 6. Keiji Katata (Pioneer) proposed that drive
sub-type 2 be made obsolete. If you are aware of common use of drive sub-type
2, please respond to this message.
Kind Regards,
Bill McFerrin
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