Question on SAT re: translation of STANDBY

Bill.Martin at emulex.com Bill.Martin at emulex.com
Sat Jan 31 14:06:52 PST 2009


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r0901310_f.htm">HTML-formatted message</a>

Mark:
I have looked in ATA8-ACS, and I cannot find the wording that mandates this. 
There is no count field in the STANDBY IMMEDIATE command, but there is
nothing to indicate that the timer is disabled when the device transitions
back to active.  The SCSI command requires that the timer be disabled until
another START STOP UNIT command is received.
Bill Martin
Emulex
Office of Technology
Industry Standards
916 772-3658
916 765-6875 (Cell)
bill.martin at emulex.com
From: Mark Overby [mailto:MOverby at nvidia.com]
Sent: Friday, January 30, 2009 9:13 AM
To: Martin, Bill; t10 at t10.org
Cc: Ayalasomayajula, Narayan
Subject: Re: Question on SAT re: translation of STANDBY
Issuing STANDBY IMMEDIATE forces the timer to be disable until you return to
the active state. (It has an equivalent behavior of the timer going to zero
immediately) (I'm excluding the unload feature of the standby immediate for
simplicity). So I believe it accomplishes what was expected.
Also, when that translation was first created - no timers were supported.
On 1/29/09 11:36 PM, "Bill.Martin at Emulex.Com" <Bill.Martin at Emulex.Com> wrote:
SAT2r6 states in table 45 that if the power condition is 03 - standby then
"If the ATA flush command was sent (step 2) and completes
without error, then the SATL shall send an ATA STANDBY IMMEDIATE command to
the ATA device;"
However, SBCr17 states that if a START STOP UNIT command is processed with
the POWER CONDITION field set to ACTIVE, IDLE, or STANDBY, then:
a) the logical unit shall transition to the specified power condition; and
b) the device server shall disable the idle condition timer if it is active
(see SPC-4) and disable the standby condition timer if it is active (see
SPC-4) until another START STOP UNIT command is processed that returns
control of the power condition to the logical unit, or a logical unit reset
occurs.
This requires disabling the standby condition timer. This would require
setting the count field to zero in the STANDBY command sent to the ATA
device.
Was there a reason for not setting the count field to zero, or was this an
oversight?  I did not find any comment addressing this in the letter ballot
comments.
Thanks,
Bill Martin
Emulex
Office of Technology
Industry Standards
916 772-3658
916 765-6875 (Cell)
bill.martin at emulex.com
________________________________
This email message is for the sole use of the intended recipient(s) and may
contain confidential information.  Any unauthorized review, use, disclosure
or distribution is prohibited.	If you are not the intended recipient, please
contact the sender by reply email and destroy all copies of the original
message.
________________________________



More information about the T10 mailing list