Re: Playing with SATA NCQ

[Jens Axboe <axboe@suse.de>]

On Thu, May 26 2005, Jeff Garzik wrote:
> >+	return 0;
> >+}
> >+
> >+/**
> >  *	ata_bus_probe - Reset and probe ATA bus
> >  *	@ap: Bus to probe
> >  *
> >@@ -2753,6 +2830,16 @@
> > 	struct ata_port *ap = qc->ap;
> > 	unsigned int tag, do_clear = 0;
> > 
> >+	if (likely(qc->flags & ATA_QCFLAG_ACCOUNT)) {
> >+		if (qc->flags & ATA_QCFLAG_NCQ) {
> >+			assert(ap->ncq_depth);
> >+			ap->ncq_depth--;
> >+		} else {
> >+			assert(ap->depth);
> >+			ap->depth--;
> >+		}
> >+	}
> 
> why is this accounting conditional?

I double checked this. If you agree to move the setting of QCFLAG_ACTIVE
_after_ successful ap->ops->qc_issue(qc) and clear it _after_
__ata_qc_complete(qc) then I can just use that bit and kill
ATA_QCFLAG_ACCOUNT.

What do you think?

-- 
Jens Axboe