Clarification from SAS 1.1 Standard (T10/1601-D)
Elliott, Robert (Server Storage)
Elliott at hp.com
Wed Oct 19 14:24:17 PDT 2005
* From the T10 Reflector (t10 at t10.org), posted by:
* "Elliott, Robert (Server Storage)" <Elliott at hp.com>
*
> * From the T10 Reflector (t10 at t10.org), posted by:
> * David Bergman <dbergman at dalsemi.com>
> *
> I have 3 spec clarification questions:
>
> 1) Section 4.4.2.3. I read this section in 2 possible ways. Could I
> please get an answer to which reading is correct?
>
> * Reading 1 - The expander will perform a hard reset on all of the
> other phys within the port, but not on any of the phys
> external to
> the port. I think this is the intended reading.
> * Reading 2 - The expander will not perform a hard reset on any
> other phys, even in the same port.
You have to carefully differentiate between these terms in this section:
* link reset sequence: OOB + speed negotiation + IDENTIFY
* hard reset sequence: OOB + speed negotiation + HARD_RESET + OOB +
speed
An expander device never generates a _hard_ reset sequence on any of its
phys because of an incoming hard reset sequence. It does, however,
generate a _link_ reset sequence for all phys contained in the same port
as the phy that received the hard reset sequence (see the rule in
4.4.2.1, which applies all ports).
> 2) Section 7.9.5.3.2.2 refers to a Tx Identify Address Frame request
> being a gating item to this state transition. I am unclear
> where this request originates, and under what circumstances. Table
K.5
> seems to indicate it comes from the Management Application layer, but
the
> conditions for this request are unclear to me. Could I please get an
> explanation of the conditions for this Tx Identify Address
> Frame request?
That represents the ability for a device to let its software/firmware
control when to send the IDENTIFY address frame, implying there could be
a delay before it chooses to do so.
> 3) I have found no change bars in revision 10 of this document. Does
> that mean it is identical to revision 9E?
Revision 10 was the one forwarded, so it has no revision history or
change bars. It's very close to 9e; you can sort the comments by date
in 05-169r6 and see what changed since July 24th.
> Thanks for the clarifications.
>
> Dave Bergman
> Dallas Semiconductor
> dbergman at dalsemi.com
> (972) 371-3112
--
Rob Elliott, elliott at hp.com
Hewlett-Packard Industry Standard Server Storage Advanced Technology
https://ecardfile.com/id/RobElliott
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