Re: Playing with SATA NCQ

[Jeff Garzik <jgarzik@pobox.com>]

Jens Axboe wrote:
> Yeah, I'm not a huge fan of the need for the above code... If every qc
> was tied to a SCSI command, we could just ask for a later requeue of the
> request as is currently done with NCQ commands. Alternatively, we could
> add an internal libata qc queue for postponing these commands. That
> would take a little effort, as the sync errors reported by
> ata_qc_issue() would then be need to signalled async through the
> completion callback instead.
> 
> Jeff, what do you think?

Just use the SCSI layer for requeueing.  That's what I intended.

Every qc that matters can be requeued.  Just don't worry about 
non-queued, non-fast-path commands.  They are typically used in 
functions that will immediately notice a failure, and handle it accordingly.

	Jeff