[SCSI] libsas: restore scan order

ata devices are always scanned after ssp.  Prior to the ata error
handling reworks libsas would tend to scan devices in ascending expander
phy order.  Restore this ordering by deferring ssp discovery to a
DISCE_PROBE event, and keep the probe order consistent with the
discovery order, not the placement of sata devices.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/libsas/sas_ata.c

@@ -683,35 +683,6 @@ static void sas_get_ata_command_set(struct domain_device *dev)
 		dev->sata_dev.command_set = ATAPI_COMMAND_SET;
 }
 
-void sas_probe_sata(struct work_struct *work)
-{
-	struct domain_device *dev, *n;
-	struct sas_discovery_event *ev =
-		container_of(work, struct sas_discovery_event, work);
-	struct asd_sas_port *port = ev->port;
-
-	clear_bit(DISCE_PROBE, &port->disc.pending);
-
-	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
-		int err;
-
-		spin_lock_irq(&port->dev_list_lock);
-		list_add_tail(&dev->dev_list_node, &port->dev_list);
-		spin_unlock_irq(&port->dev_list_lock);
-
-		err = sas_rphy_add(dev->rphy);
-
-		if (err) {
-			SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
-				    __func__, dev->parent ? "exp-attached" :
-							    "direct-attached",
-				    SAS_ADDR(dev->sas_addr), err);
-			sas_unregister_dev(port, dev);
-		} else
-			list_del_init(&dev->disco_list_node);
-	}
-}
-
 /**
  * sas_discover_sata -- discover an STP/SATA domain device
  * @dev: pointer to struct domain_device of interest

drivers/scsi/libsas/sas_discover.c

@@ -152,7 +152,7 @@ static int sas_get_port_device(struct asd_sas_port *port)
 
 	dev->rphy = rphy;
 
-	if (dev_is_sata(dev))
+	if (dev_is_sata(dev) || dev->dev_type == SAS_END_DEV)
 		list_add_tail(&dev->disco_list_node, &port->disco_list);
 	else {
 		spin_lock_irq(&port->dev_list_lock);
@@ -198,8 +198,34 @@ void sas_notify_lldd_dev_gone(struct domain_device *dev)
 	}
 }
 
-/* ---------- Common/dispatchers ---------- */
+static void sas_probe_devices(struct work_struct *work)
+{
+	struct domain_device *dev, *n;
+	struct sas_discovery_event *ev =
+		container_of(work, struct sas_discovery_event, work);
+	struct asd_sas_port *port = ev->port;
+
+	clear_bit(DISCE_PROBE, &port->disc.pending);
+
+	list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+		int err;
+
+		spin_lock_irq(&port->dev_list_lock);
+		list_add_tail(&dev->dev_list_node, &port->dev_list);
+		spin_unlock_irq(&port->dev_list_lock);
 
+		err = sas_rphy_add(dev->rphy);
+
+		if (err) {
+			SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
+				    __func__, dev->parent ? "exp-attached" :
+							    "direct-attached",
+				    SAS_ADDR(dev->sas_addr), err);
+			sas_unregister_dev(port, dev);
+		} else
+			list_del_init(&dev->disco_list_node);
+	}
+}
 
 /**
  * sas_discover_end_dev -- discover an end device (SSP, etc)
@@ -213,18 +239,10 @@ int sas_discover_end_dev(struct domain_device *dev)
 
 	res = sas_notify_lldd_dev_found(dev);
 	if (res)
-		goto out_err2;
-
-	res = sas_rphy_add(dev->rphy);
-	if (res)
-		goto out_err;
+		return res;
+	sas_discover_event(dev->port, DISCE_PROBE);
 
 	return 0;
-
-out_err:
-	sas_notify_lldd_dev_gone(dev);
-out_err2:
-	return res;
 }
 
 /* ---------- Device registration and unregistration ---------- */
@@ -491,7 +509,7 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 	static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
 		[DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
 		[DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
-		[DISCE_PROBE] = sas_probe_sata,
+		[DISCE_PROBE] = sas_probe_devices,
 		[DISCE_DESTRUCT] = sas_destruct_devices,
 	};
 

drivers/scsi/libsas/sas_expander.c

@@ -806,9 +806,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 		child->rphy = rphy;
 		sas_fill_in_rphy(child, rphy);
 
-		spin_lock_irq(&parent->port->dev_list_lock);
-		list_add_tail(&child->dev_list_node, &parent->port->dev_list);
-		spin_unlock_irq(&parent->port->dev_list_lock);
+		list_add_tail(&child->disco_list_node, &parent->port->disco_list);
 
 		res = sas_discover_end_dev(child);
 		if (res) {

include/scsi/sas_ata.h

@@ -44,7 +44,6 @@ void sas_ata_task_abort(struct sas_task *task);
 void sas_ata_strategy_handler(struct Scsi_Host *shost);
 void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 		struct list_head *done_q);
-void sas_probe_sata(struct work_struct *work);
 void sas_ata_schedule_reset(struct domain_device *dev);
 void sas_ata_wait_eh(struct domain_device *dev);
 #else
@@ -72,10 +71,6 @@ static inline void sas_ata_eh(struct Scsi_Host *shost, struct list_head *work_q,
 {
 }
 
-static inline void sas_probe_sata(struct work_struct *work)
-{
-}
-
 static inline void sas_ata_schedule_reset(struct domain_device *dev)
 {
 }