Re: ata2: SATA link down (SStatus 611 SControl 300)

[Tejun Heo]

Tejun Heo wrote:
> Paul Collins wrote:
> > Tejun Heo <htejun@xxxxxxxxx> writes:
> >
> > > Paul Collins wrote:
> > > > I found a setting labelled "SATA Power Management".  It was set to
> > > > "Enable".  When I set it to "Disable", 2.6.25-rc9 detected the optical
> > > > drive.
> > > This can't be something changed between 2.6.24 and 2.6.25-rc9.  Can
> > > you please double check that?
> >
> > I double-checked as follows:
> >
> > * Verified "SATA Power Management" set to "Enable"
> > * Verified optical device present in 2.6.24.3
> > * Verified optical device not present in 2.6.25-rc9
>
> Thanks for checking.  Yeah, on the second though, ata_piix as of 
> 2.6.24.3 doesn't have SCR access at all, so it would have just worked. 
> Maybe what's necessary is more refined link onlineness test.  I'll prep 
> a patch.

Can you please try the attached patch?  Thanks.

--
tejun
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index be95fdb..e3ddefd 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3966,11 +3966,26 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
 
 	/* if SATA, resume link */
 	if (ap->flags & ATA_FLAG_SATA) {
+		u32 sstatus;
+
 		rc = sata_link_resume(link, timing, deadline);
 		/* whine about phy resume failure but proceed */
 		if (rc && rc != -EOPNOTSUPP)
 			ata_link_printk(link, KERN_WARNING, "failed to resume "
 					"link for reset (errno=%d)\n", rc);
+
+		/* force hardreset if the link is sleeping */
+		if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0) {
+			u8 ipm = sstatus >> 8;
+
+			if (ipm == 2 || ipm == 6) {
+				ata_link_printk(link, KERN_INFO,
+					"link in %s mode, forcing hardreset\n",
+					ipm == 2 ? "partial" : "slumber");
+				ehc->i.action |= ATA_EH_HARDRESET;
+				return 0;
+			}
+		}
 	}
 
 	/* Wait for !BSY if the controller can wait for the first D2H
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c