Re: [PATCH + RFC] Beginning of some updates to scsi mid layer

Doug Ledford
2002-06-29T10:05:09Z

On Fri, Jun 28, 2002 at 07:04:28PM -0700, Matthew Jacob wrote:
>
> FWIW, Bob Snively (on T10 commitee) has always claimed that the correct
> response to QUEUE FULL is immediate command resubmission (i.e., *don't* wait
> for a command to complete (the QFULL may have resulted from commands being
> processed for *another* initiator), and *don't* a period of time for things to
> 'get better').
>
> I'm not sure agree with this 100%, but he might have a point.

No, absolutely not! Faster drivers are capable of restarting commands on
the bus so fast that in this scenario they can flood the bus with
selection, command, queue full sequences and not allow *any* commands to
complete because the bus is always tied up (this was, in fact, one of the
reasons that I had to put the queue handling code in the aic7xxx driver
when I did).

--
Doug Ledford <dledford@redhat.com> 919-754-3700 x44233
Red Hat, Inc.
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Raleigh, NC 27606