[SCSI] libsas, libata: fix start of life for a sas ata_port

This changes the ordering of initialization and probing events from:
  1/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate ata_port and schedule port probe in DISCE_PROBE
...to:
  1/ allocate ata_port in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  2/ allocate rphy in PORTE_BYTES_DMAED, DISCE_REVALIDATE_DOMAIN
  3/ schedule port probe in DISCE_PROBE

This ordering prevents PHYE_SIGNAL_LOSS_EVENTS from sneaking in to
destrory ata devices before they have been fully initialized:

  BUG: unable to handle kernel paging request at 0000000000003b10
  IP: [<ffffffffa0053d7e>] sas_ata_end_eh+0x12/0x5e [libsas]
  ...
  [<ffffffffa004d1af>] sas_unregister_common_dev+0x78/0xc9 [libsas]
  [<ffffffffa004d4d4>] sas_unregister_dev+0x4f/0xad [libsas]
  [<ffffffffa004d5b1>] sas_unregister_domain_devices+0x7f/0xbf [libsas]
  [<ffffffffa004c487>] sas_deform_port+0x61/0x1b8 [libsas]
  [<ffffffffa004bed0>] sas_phye_loss_of_signal+0x29/0x2b [libsas]

...and kills the awkward "sata domain_device briefly existing in the
domain without an ata_port" state.

Reported-by: Michal Kosciowski <michal.kosciowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 13b5891..629a086 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -72,6 +72,7 @@
 	struct asd_sas_phy *phy;
 	struct sas_rphy *rphy;
 	struct domain_device *dev;
+	int rc = -ENODEV;
 
 	dev = sas_alloc_device();
 	if (!dev)
@@ -110,9 +111,16 @@
 
 	sas_init_dev(dev);
 
+	dev->port = port;
 	switch (dev->dev_type) {
-	case SAS_END_DEV:
 	case SATA_DEV:
+		rc = sas_ata_init(dev);
+		if (rc) {
+			rphy = NULL;
+			break;
+		}
+		/* fall through */
+	case SAS_END_DEV:
 		rphy = sas_end_device_alloc(port->port);
 		break;
 	case EDGE_DEV:
@@ -131,7 +139,7 @@
 
 	if (!rphy) {
 		sas_put_device(dev);
-		return -ENODEV;
+		return rc;
 	}
 
 	rphy->identify.phy_identifier = phy->phy->identify.phy_identifier;
@@ -139,7 +147,6 @@
 	sas_fill_in_rphy(dev, rphy);
 	sas_hash_addr(dev->hashed_sas_addr, dev->sas_addr);
 	port->port_dev = dev;
-	dev->port = port;
 	dev->linkrate = port->linkrate;
 	dev->min_linkrate = port->linkrate;
 	dev->max_linkrate = port->linkrate;