[MtFuji] MMC / Mt Fuji: 8 bytes and 4 bytes flavors of 'No Event'

Bill McFerrin billmc37 at ctesc.net
Tue Apr 7 12:14:53 PDT 2009

* From the T10 Reflector (t10 at t10.org), posted by:
* Bill McFerrin <billmc37 at ctesc.net>
Your are right: The response is incorrect. Fuji agrees.
The more accurate wording you suggested (“If no event /of the requested 
notification class/ has occurred, …”) is a good thing. It might be 
useful to add a "for example".
David Burg wrote:
> Hello,
> During our testing of Windows 7, our engineers noticed a difference in 
> the devices’ implementation of GESN command response to say the same 
> ‘no event’ answer. Below is a capture of an 8 bytes answer from one 
> device and of an 4 bytes answer from another device.
> (Note that BusTrace incorrectly interpreted the Polled bit as Immed.)
> We believe this complies to MMC’s:
> cid:image002.jpg at 01C9AC5C.CBEA04D0
> (One might want to be careful to clarify “If no event /of the 
> requested notification class/ has occurred, …” because event may occur 
> in another class and yet can’t be reported.)
> The other device responds:
> This does not seem allowed by the current spec, although it is not 
> completely obvious.
> Also, some software engineers thought they would get NEA = 1b and 4 
> bytes, based on the name of that bit “Not Event Available”. >From an 
> English language point of view, there is indeed no event available. 
> However, the spec definition of the bit then contradicts with what one 
> would expect out of English language alone:
> “If NEA (No Event Available) is set to one, the Drive supports none of 
> the requested notification classes. If NEA
> is set to zero, at least one of the requested notification classes is 
> supported.”
> This sounds more like “No Requested Class Supported”.
> So, Microsoft believes this GESN section should be reviewed in detail 
> and clarified.
> With regards,
> David.
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