Behavior of TEST UNIT READY command in idle and standby power conditions

Matthew Jacob mj at feral.com
Wed Nov 28 06:52:25 PST 2012


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1211284_f.htm">HTML-formatted message</a>

On 11/28/2012 4:30 AM, Knight, Frederick wrote:
>
> SPC and SBC already say that if the command is able to be processed, 
> then process it.
>
> If the device went to idle, and it gets a READ, and the device is able 
> to process the READ, then do it.NO CHECK CONDITION.
>
> Therefore, if the device gets a TUR and the device is able to process 
> a READ (no matter what power condition it is in), then the status is 
> GOOD.There is no CHECK CONDITION on that TUR.AND, as was pointed out, 
> it is still possible that the device will change state in between the 
> TUR and the READ, so the TUR could still return GOOD and the READ 
> return a CHECK CONDITION.
>
> If the device is NOT able to process a READ, then when the TUR comes 
> in, the device returns CHECK CONDITION -- NOT READY -- INITIALIZING 
> COMMAND REQUIRED.The host sends START UNIT.When the START UNIT 
> completes the host sends the READ (it might also resend the TUR before 
> sending the READ).If the device needs time to get ready, it takes that 
> time during the processing of the START UNIT command.
>
> Not complex -- just 2 cases.GOOD or INITIALIZING COMMAND REQUIRED.
>
>
Very well put. That's what I was trying to convey.



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