From: Larry Chen <Larry_Chen@pmc-sierra.com>
To: "T10 (t10@t10.org)" <t10@t10.org>
Subject: SAS error recovery use case - Device Server detected Data Offset 
	Error
Date: Thu, 29 Jun 2006 17:07:10 -0700
X-Message-Number: 7001
Formatted message: HTML-formatted message

Hi,
I have an SAS error recovery use case which can not
Solve by myself after reading the SAS-1.1 specification Rev 9e.
The use case scenario starts when the Device Server detects
A Data Offset Error (assume that the first of two data
Frames is dropped/lost) during a Write command.
As stated in the spec, the Device Server sets the appropriate
SCSI error message in the SSP_RESPONSE frame and sends
It to the initiator.
Ex)
Initiator						   Target
---------------SSP_Command(WRITE)-------------->
<-------------------------------ACK-------------------------
<------------------------------SSP_XFR_RDY----------
---------------------------------ACK------------------------->
--------------SSP_DATA-1---------------> DROPPED/LOST
--------------SSP-DATA-2-------------------------------->      Data Offset
Error is detected
<--------------------------------ACK-2-----------------------
<-------------SSP_RESPONSE(DATA_OFFSET_ERROR)
QUESTION-1: Can SSP_RESPONSE be sent in the same connection
Or does it need to open a new connection?
QUESTION-2: If SSP_RESPONSE is received when ACK-TOV is still
Running, is the ACK_TOV timer supposed to be cancelled? If so, can someone
Refer me to the place in the SAS spec where this is mentioned.
QUESTION-3: Does closing a connection force cancelling of all
Active timers, such as, ACK_TOV timer?
QUESTION-4: does SAS spec mention about how ACK_TOV,
DONE_TOV, AND BREAK_TOV timers interact e.g. priority, preemption?