Hi Bill...
 
I'm suggesting the new item d) is required so we don't have the exact same race condition issue when the "slower" trained device acquires dword sync on the 4th, 5th, or 6th dword of a TRAIN_DONE (i.e. there aren't enough of the TRAIN_DONE dwords left to detect 3 out of 6 redundant rule in the primitive sequence)
 
Without item d), it would be possible to then transition to SP30 without detecting the TRAIN_DONE, and have the faster device move to SAS_PHY_Ready, and we've got the same problem again.
 
Essentially, I'm suggesting a device doesn't say TRAIN_DONE until it's reached the point where it's actually seeing/decoding the other devices primitives, instead of just acquiring dword sync as the gating factor.
 
Brian

From: Bill.Martin@Emulex.Com [mailto:Bill.Martin@Emulex.Com]
Sent: Wednesday, November 05, 2008 12:16 PM
To: Day, Brian; t10@t10.org
Subject: Response to 08-425r0

Brian:

 

I understood the need to detect the TRAIN_DONE primitive in the training state; however, I do not see the reason that a TRAIN or TRAIN_DONE has to be received before exiting this state.  The device will continue sending TRAIN_DONE until a TRAIN_DONE is received, so the device that is later entering the training sequence will see a TRAIN or TRAIN_DONE sequence during its training process, and should be able to train on either pattern.

 

I would like to see the new item d) in 6.8.4.12.5.

 

I am sorry that I did not catch this part of your proposal in our discussions on Monday.

 

Bill Martin

Emulex
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bill.martin@emulex.com