SAS transition from SP12 to SP0

Kevin_Marks at Dell.com Kevin_Marks at Dell.com
Fri Nov 21 16:29:02 PST 2008


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r0811214_f.htm">HTML-formatted message</a>

Bill,
I'm a little confused.	If you were in SP12 aren't you a SAS phy?  If a
SATA device is hot plugged when the initiator or expander was in SP12,
so what if you have to wait a HotPlug time out.
Kevin
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of
Bill.Martin at emulex.com
Sent: Friday, November 21, 2008 12:51 PM
To: Martin.Schulze at wdc.com
Cc: t10 at t10.org
Subject: RE: SAS transition from SP12 to SP0
Martin:
The issue here is that if you are not connected to a SAS device, you
will transition to SP1, and there you will have to wait for a hotplug
timeout before you re-enter SP0 and transmit a COMMINIT.  At that point,
hopefully both devices will be in sync and they will both detect
COMMINIT/COMWAKE appropriately and continue.  If the COMMINIT detected
was passed into SP0 you would avoid this hotplug timeout.
Bill Martin
Emulex
Office of Technology
Industry Standards
916 772-3658
916 765-6875 (Cell)
bill.martin at emulex.com
From: Martin Schulze [mailto:Martin.Schulze at wdc.com] 
Sent: Thursday, November 20, 2008 3:38 PM
To: Martin, Bill
Cc: t10 at t10.org
Subject: RE: SAS transition from SP12 to SP0
>From my reading of the standard, I do not believe the SP machine needs
to remember that receiving a COMINIT is what brought it to SP0.  Nor
does it need to receive a COMINIT in SP0:OOB_COMINIT.  Sending a COMINIT
in SP0 and then both sending and receiving COMSAS (in other states) is
sufficient to bring the bus to the start of SNW1.
Martin Schulze
Western Digital
________________________________
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of
Bill.Martin at Emulex.Com
Sent: Thursday, November 20, 2008 3:18 PM
To: t10 at t10.org
Cc: Shiro.Suzuki at Emulex.Com
Subject: FW: SAS transition from SP12 to SP0
I have not seen a response on this, does anyone have any input on the
original intent on this transition?
Thanks,
Bill Martin
Emulex
Office of Technology
Industry Standards
916 772-3658
916 765-6875 (Cell)
bill.martin at emulex.com
From: owner-t10 at t10.org [mailto:owner-t10 at t10.org] On Behalf Of
Bill.Martin at emulex.com
Sent: Monday, November 17, 2008 1:11 PM
To: t10 at t10.org; Elliott at hp.com
Subject: SAS transition from SP12 to SP0
When a SAS device is in the SP12::SAS_AwaitSNW, receives a COMINIT, and
transitions to the SP0:OOB_COMINIT, shall the device remember that it
has detected COMINIT or shall it wait for another COMINIT to be
received?  There is no mention of carrying a state variable forward to
the SP0 state.
Thanks for any and all opinions.
Bill Martin
Emulex
Office of Technology
Industry Standards
916 772-3658
916 765-6875 (Cell)
bill.martin at emulex.com



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