[SCSI] libsas: let libata recover links that fail to transmit initial sig-fis

libsas fails to discover all sata devices in the domain.  If a device fails
negotiation and does not transmit a signature fis the link needs recovery.
libata already understands how to manage slow to come up links, so treat these
conditions as ata device attach events for the purposes of creating an
ata_port.  This allows libata to manage retrying link bring up.

Rediscovery is modified to be careful about checking changes in dev_type.  It
looks like libsas leaks old devices if the sas address changes, but that's a
fix for another patch.

Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 66 insertions, 5 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index ba1ebfe991d7..25008a42412f 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -278,26 +278,84 @@ static struct sas_internal *dev_to_sas_internal(struct domain_device *dev)
 	return to_sas_internal(dev->port->ha->core.shost->transportt);
 }
 
+static void sas_get_ata_command_set(struct domain_device *dev);
+
+int sas_get_ata_info(struct domain_device *dev, struct ex_phy *phy)
+{
+	if (phy->attached_tproto & SAS_PROTOCOL_STP)
+		dev->tproto = phy->attached_tproto;
+	if (phy->attached_sata_dev)
+		dev->tproto |= SATA_DEV;
+
+	if (phy->attached_dev_type == SATA_PENDING)
+		dev->dev_type = SATA_PENDING;
+	else {
+		int res;
+
+		dev->dev_type = SATA_DEV;
+		res = sas_get_report_phy_sata(dev->parent, phy->phy_id,
+					      &dev->sata_dev.rps_resp);
+		if (res) {
+			SAS_DPRINTK("report phy sata to %016llx:0x%x returned "
+				    "0x%x\n", SAS_ADDR(dev->parent->sas_addr),
+				    phy->phy_id, res);
+			return res;
+		}
+		memcpy(dev->frame_rcvd, &dev->sata_dev.rps_resp.rps.fis,
+		       sizeof(struct dev_to_host_fis));
+		/* TODO switch to ata_dev_classify() */
+		sas_get_ata_command_set(dev);
+	}
+	return 0;
+}
+
+static int sas_ata_clear_pending(struct domain_device *dev, struct ex_phy *phy)
+{
+	int res;
+
+	/* we weren't pending, so successfully end the reset sequence now */
+	if (dev->dev_type != SATA_PENDING)
+		return 1;
+
+	/* hmmm, if this succeeds do we need to repost the domain_device to the
+	 * lldd so it can pick up new parameters?
+	 */
+	res = sas_get_ata_info(dev, phy);
+	if (res)
+		return 0; /* retry */
+	else
+		return 1;
+}
+
 static int smp_ata_check_ready(struct ata_link *link)
 {
 	int res;
-	u8 addr[8];
 	struct ata_port *ap = link->ap;
 	struct domain_device *dev = ap->private_data;
 	struct domain_device *ex_dev = dev->parent;
 	struct sas_phy *phy = sas_get_local_phy(dev);
+	struct ex_phy *ex_phy = &ex_dev->ex_dev.ex_phy[phy->number];
 
-	res = sas_get_phy_attached_sas_addr(ex_dev, phy->number, addr);
+	res = sas_ex_phy_discover(ex_dev, phy->number);
 	sas_put_local_phy(phy);
+
 	/* break the wait early if the expander is unreachable,
 	 * otherwise keep polling
 	 */
 	if (res == -ECOMM)
 		return res;
-	if (res != SMP_RESP_FUNC_ACC || SAS_ADDR(addr) == 0)
+	if (res != SMP_RESP_FUNC_ACC)
 		return 0;
-	else
-		return 1;
+
+	switch (ex_phy->attached_dev_type) {
+	case SATA_PENDING:
+		return 0;
+	case SAS_END_DEV:
+		if (ex_phy->attached_sata_dev)
+			return sas_ata_clear_pending(dev, ex_phy);
+	default:
+		return -ENODEV;
+	}
 }
 
 static int local_ata_check_ready(struct ata_link *link)
@@ -584,6 +642,9 @@ static void sas_get_ata_command_set(struct domain_device *dev)
 	struct dev_to_host_fis *fis =
 		(struct dev_to_host_fis *) dev->frame_rcvd;
 
+	if (dev->dev_type == SATA_PENDING)
+		return;
+
 	if ((fis->sector_count == 1 && /* ATA */
 	     fis->lbal         == 1 &&
 	     fis->lbam         == 0 &&