[t13] Re: Removable Media Status Notification feature set

Pat LaVarre p.lavarre at ieee.org
Fri Apr 2 12:26:12 PST 2004


This message is from the T13 list server.


> Removable Media Status Notification feature
> set of ATA.

Here I suppose we mean the ATA ops x EF 95, x EF 31, and xDA.

I remember WHQL sometimes required the device to support those ops, but 
last I checked the relevant WHQL test erroneously required op xA0 03 
Packet/ Request Sense to leave the x3F6 & x01 ERR bit unchanged, ouch, 
e.g. even in the presence of a UDMA CRC failure.

> I believe that this function is overlapped to SBC/MMC command set 
> (Packet)

Yes redundant with PDT x05 MMC op x4A 
GPCMD_GET_EVENT_STATUS_NOTIFICATION.

Massively distributed as legacy for PDT x 0E/ 07/ 04/ 00 RBC/ SBC ...  
I mis/remember mostly I studied this in the Win 95 B ATAPI that 
couldn't copy odd lengths of bytes per cdb.  Rumour, be it truth or 
slander, says Win XP/ 2K didn't bother with these ATA ops.

Are you saying someone is trying to revive them?  Please no?

> and is incomplete to use in product.

Incomplete as you describe below, yes.

> So in MMC/Fuji discussion we were
> concluded that Packet device and its host software does not use this
> feature set in ATA.

Yes please.

> MMC has embedded changer model. SBC/MMC have many different write 
> protects
> or similar media and device combination status. Removable Media Status
> Notification feature set of ATA cannot cover these items.
> ATA layer persistent prevent, C/DVD class layer persistent prevent and
> application layer prevent may conflict each other.

Yes.

> I think if T13 group needs to keep this feature in ATA, someone must
> explain this feature in MMC WG.

Accurate doc would be nice, sure.

The design element I maybe most enjoyed was having the host conclude 
that an SBC op x2B Seek was an MMC op x2B Seek Immediate which 
completed not when x3F6 Status & x40 DRDY rose but instead prematurely 
when op xDA set x3F6 Status & x01 ERR rose because the disk was 
write-protected.

> And T13 group may need to add some
> descriptions to keep compatibility with SBC/MMC command set.

Can you say more about what you have in mind?

> I'm waiting for any commnet.

Hope this helps.

Pat LaVarre




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