SAS SL_CC missing a Connection Closed (Break Received)

George Penokie gop at us.ibm.com
Tue Apr 29 14:19:31 PDT 2003


* From the T10 Reflector (t10 at t10.org), posted by:
* George Penokie <gop at us.ibm.com>
*




Rob,
You are correct that there is a problem but the solution you propose would
result in multiple notifications to the port layer that a connection has
closed or conflicting notifications indicating that the connection has
failed to open and was then closed. The correct place to fix this is in
section 7.14.4.5.3.

Change from:

7.14.4.5.3 Transition SL_CC3:Connected to SL_CC5:BreakWait
This transition shall occur if a Request Break message is received and a
BREAK Received message has not
been received.

To:

7.14.4.5.3 Transition SL_CC3:Connected to SL_CC5:BreakWait
This transition shall occur if:
a) a Request Break message is received;
b) a BREAK Received message has not been received; and
c) after sending a Connection Closed (Break Received) confirmation to the
port layer


Bye for now,
George Penokie

Dept 2C6  114-2 N212
E-Mail:    gop at us.ibm.com
Internal:  553-5208
External: 507-253-5208   FAX: 507-253-2880




                                                                                                                                       
                      "Elliott, Robert                                                                                                 
                      (Server Storage)"        To:       <t10 at t10.org>                                                                 
                      <Elliott at hp.com>         cc:                                                                                     
                      Sent by:                 Subject:  SAS SL_CC missing a Connection Closed (Break Received)                        
                      owner-t10 at t10.org                                                                                                
                                                                                                                                       
                                                                                                                                       
                      04/29/2003 12:26                                                                                                 
                      PM                                                                                                               
                                                                                                                                       
                                                                                                                                       




If the protocol-specific link layer (SSP or SMP) sends Transmit Break to
SL_CC, SL_CC leaves the Connected state and goes to the BreakWait state .
This state sends a BREAK and waits for one in reply.  SL_CC then goes to
idle when either a BREAK arrives in reply, or the Break Timeout timer
expires.


If the timer expires, Connection Closed (Break Timeout) is sent up to the
port layer (see the SL_CC5:BreakWait to SL_CC0:Idle text).


If a BREAK arrives, however, no Connection Closed is ever sent up to the
port layer.  I think Connection Closed (Break Received) needs to be sent.


Change:
"
7.14.4.7.2 Transition SL_CC5:BreakWait to SL_CC0:Idle
This transition shall occur after receiving a BREAK Received message or if
the Break Timeout timer expires. If
a BREAK Received message is not received before the Break Timeout timer
expires, this state shall send a
Connection Closed (Break Timeout) confirmation to the port layer before
making this transition."


to:
"
7.14.4.7.2 Transition SL_CC5:BreakWait to SL_CC0:Idle
This transition shall occur after receiving a BREAK Received message or if
the Break Timeout timer expires. If
a BREAK Received message is not received before the Break Timeout timer
expires, this state shall send a
Connection Closed (Break Timeout) confirmation to the port layer before
making this transition. <<If a BREAK
Received message is received, this state shall send a Connection Closed
(Break Received) confirmation
to the port layer before making this transition.>>"





--
Rob Elliott, elliott at hp.com
Hewlett-Packard Industry Standard Server Storage Advanced Technology
https://ecardfile.com/id/RobElliott










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