P1394 Mail Archive: P1394> ABORTED - UNEXPECTED ... (Was Re: Revised PWG1394 Cmd Set)

P1394 Mail Archive: P1394> ABORTED - UNEXPECTED ... (Was Re: Revised PWG1394 Cmd Set)

P1394> ABORTED - UNEXPECTED ... (Was Re: Revised PWG1394 Cmd Set)

Akihiro Shimura (shimura@pure.cpdc.canon.co.jp)
Fri, 31 Jul 1998 14:41:26 +0900 (JST)

On Mon, 20 Jul 1998 10:05:11 -0700 (PDT)
Greg Shue <gregs@sdd.hp.com> wrote:
(snip)
> It may be reasonable for a target to enforce seeing
> sequential command tags in order to recover from this
> situation. If the queue's Execution Agent completed
> all commands in that queue with a status of "ABORTED -
> UNEXPECTED COMMAND TAG VALUE", then the initiator has
> a chance to recover from the situation. This also means
> that an ABORT TASK function causes all successive commands
> on the associated queue to be aborted without affecting
> the other queue.

I have a question about actions taken by the initiator.

I suppose that if the target's agent finds this situation, target
enters from 'execute' state to 'abort all subsequent commands' state
(in order not to execute the commands still not fetched).
The initiator will wait until target aborts all subsequent commands
destined to the queue.
(Target may be executing commands destined to another queue at this
moment.)

After all subsequent commands are aborted, the initiator will requeue
aborted commands with properly assigned sequence ids.
I think, initiator "needs to" restore target's agent state to
'execute' without affecting the execution of another queue at this
point.

How does target find the initiator recovered from the
situation? (I may be misunderstanding the process.)

In the model I described in previous mails, the initiator does not
take recovery action at all.

Because descriptive explanation may make it hard to be well
understood, I am preparing some slides for explanation.

Ueda-san from Canon will make a presentation for this alternative
model at upcoming Toronto meeting.

Akihiro Shimura

--
 Akihiro Shimura (shimura@pure.cpdc.canon.co.jp)
 Office Imaging System Promotion Project
 CANON INC.