XL State Machine Problem
Elliott, Robert (Server Storage)
elliott at hp.com
Fri Mar 26 12:22:15 PST 2004
* 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:
> * Fred Dutton <fred.dutton at qlogic.com>
> SAS 1.1 Rev 04, sub clause 126.96.36.199, does not mention the
> need to send a Transmit Break request to the ECR when a BREAK
> Received message is received.
> I think a BREAK Received message should be handled in a way
> analogous to the way a CLOSE Received message is handled in the
> XL8:Close_Wait state.
> Suggested wording:
> "If a BREAK Received message is received, this state shall
> send a Transmit Break request to the ECR."
> Fred Dutton
> QLogic Corporation
XL10 has already "released path resources" so there is no recipient phy
on the other side of the ECR to receive the Transmit Break
XL only enters XL10 because:
XL3:Open_Confirm_Wait received a Transmit Break indication
XL6:Open_Response_Wait received a Transmit Break indication
XL7:Connected received a Transmit Break indication
XL8:Close_Wait received a Transmit Break indication
All these mean the remote phy was the source of the break. If it had
sent Transmit BREAK because it received a BREAK, it has concurrently
sent a BREAK in response from its own XL10 state.
A BREAK received by this phy in XL10 just closes the BREAK/BREAK round
trip on this side. No further propagation is necessary.
Rob Elliott, elliott at hp.com
Hewlett-Packard Industry Standard Server Storage Advanced Technology
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