Re: 2.6.23-mm1

[Jeff Garzik]

Torsten Kaiser wrote:
> On 10/13/07, Torsten Kaiser <just.for.lkml@xxxxxxxxxxxxxx> wrote:
> > Wait!
> >
> > I think I found the bug: Its a evil interaction between the above
> > patch and the swncq patch that is applied later.
> > The qc_defer patch removes the old ata_scmd_need_defer that was always
> > called for all drivers and substitutes it for ata_std_qc_defer and
> > adds it as aops->qc_defer to all drivers that support NCQ *at that
> > point*.
> > Then the swncq patch adds a new NCQ capable driver, but the nobody
> > added the qc_defer-ops to the ops-structure that is added. So swncq
> > will never defer any commands and the first command that would need to
> > be defered (the SMART commands) blows up, if there is still another
> > command in flight.
> >
> > I will only add the qc_defer and try this...
>
> 3 boots, all worked. So I'm very sure that was the bug, but I will now
> do a little load testing...
>
> The only strange thing about 2.6.23-mm1 is, that it takes ~4 second
> more to boot.

So, you basically applied the attached patch?

Yeah, absence of qc_defer for an NCQ-capable chip would do it.

	Jeff


diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c
index cf5c85e..240a892 100644
--- a/drivers/ata/sata_nv.c
+++ b/drivers/ata/sata_nv.c
@@ -554,6 +554,7 @@ static const struct ata_port_operations nv_swncq_ops = {
 	.bmdma_start		= ata_bmdma_start,
 	.bmdma_stop		= ata_bmdma_stop,
 	.bmdma_status		= ata_bmdma_status,
+	.qc_defer		= ata_std_qc_defer,
 	.qc_prep		= nv_swncq_qc_prep,
 	.qc_issue		= nv_swncq_qc_issue,
 	.freeze			= nv_mcp55_freeze,