diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 60de662..43e8a1e 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -503,11 +503,10 @@ static void sas_revalidate_domain(struct work_struct *work)
 	struct domain_device *ddev = port->port_dev;
 
 	/* prevent revalidation from finding sata links in recovery */
-	mutex_lock(&ha->disco_mutex);
 	if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
 		SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
 			    port->id, task_pid_nr(current));
-		goto out;
+		return;
 	}
 
 	clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
@@ -521,20 +520,57 @@ static void sas_revalidate_domain(struct work_struct *work)
 
 	SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
 		    port->id, task_pid_nr(current), res);
- out:
-	mutex_unlock(&ha->disco_mutex);
+}
+
+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_devices,
+	[DISCE_SUSPEND] = sas_suspend_devices,
+	[DISCE_RESUME] = sas_resume_devices,
+	[DISCE_DESTRUCT] = sas_destruct_devices,
+};
+
+/* a simple wrapper for sas discover event funtions */
+static void sas_discover_common_fn(struct work_struct *work)
+{
+	struct sas_discovery_event *ev = to_sas_discovery_event(work);
+	struct asd_sas_port *port = ev->port;
+
+	sas_event_fns[ev->type](work);
+	sas_unbusy_port(port);
 }
 
 /* ---------- Events ---------- */
 
 static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
 {
+	int ret;
+	struct sas_discovery_event *ev = to_sas_discovery_event(&sw->work);
+	struct asd_sas_port *port = ev->port;
+
 	/* chained work is not subject to SA_HA_DRAINING or
 	 * SAS_HA_REGISTERED, because it is either submitted in the
 	 * workqueue, or known to be submitted from a context that is
 	 * not racing against draining
 	 */
-	scsi_queue_work(ha->core.shost, &sw->work);
+	sas_busy_port(port);
+
+	/*
+	 * discovery event probe and destruct would be called in other
+	 * discovery event like discover domain and revalidate domain
+	 * events, in some cases, we need to sync execute probe and destruct
+	 * events, so run discover events except probe/destruct in a new
+	 * workqueue.
+	 */
+	if (ev->type == DISCE_PROBE || ev->type == DISCE_DESTRUCT)
+		ret = scsi_queue_work(ha->core.shost, &sw->work);
+	else
+		ret = queue_work(ha->disc_q, &sw->work);
+
+	if (ret != 1)
+		/* queue a work fail, unbusy the ha before return */
+		sas_unbusy_port(port);
 }
 
 static void sas_chain_event(int event, unsigned long *pending,
@@ -575,18 +611,10 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
 {
 	int i;
 
-	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_devices,
-		[DISCE_SUSPEND] = sas_suspend_devices,
-		[DISCE_RESUME] = sas_resume_devices,
-		[DISCE_DESTRUCT] = sas_destruct_devices,
-	};
-
 	disc->pending = 0;
 	for (i = 0; i < DISC_NUM_EVENTS; i++) {
-		INIT_SAS_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
+		INIT_SAS_WORK(&disc->disc_work[i].work, sas_discover_common_fn);
 		disc->disc_work[i].port = port;
+		disc->disc_work[i].type = i;
 	}
 }
diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index 06c5c4b..c0fc07d 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -41,7 +41,7 @@ void sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
 		if (list_empty(&sw->drain_node))
 			list_add(&sw->drain_node, &ha->defer_q);
 	} else
-		scsi_queue_work(ha->core.shost, &sw->work);
+		queue_work(ha->event_q, &sw->work);
 }
 
 static void sas_queue_event(int event, struct sas_work *work,
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 570b2cb..7db4a28 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -822,7 +822,9 @@ static struct domain_device *sas_ex_discover_end_dev(
 
 		list_add_tail(&child->disco_list_node, &parent->port->disco_list);
 
+		sas_wait_discover_event_init(child->port);
 		res = sas_discover_sata(child);
+		sas_wait_for_discover_event_finish(child->port);
 		if (res) {
 			SAS_DPRINTK("sas_discover_sata() for device %16llx at "
 				    "%016llx:0x%x returned 0x%x\n",
@@ -847,7 +849,9 @@ static struct domain_device *sas_ex_discover_end_dev(
 
 		list_add_tail(&child->disco_list_node, &parent->port->disco_list);
 
+		sas_wait_discover_event_init(child->port);
 		res = sas_discover_end_dev(child);
+		sas_wait_for_discover_event_finish(child->port);
 		if (res) {
 			SAS_DPRINTK("sas_discover_end_dev() for device %16llx "
 				    "at %016llx:0x%x returned 0x%x\n",
@@ -1890,8 +1894,11 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent,
 				if (child->dev_type == SAS_EDGE_EXPANDER_DEVICE ||
 				    child->dev_type == SAS_FANOUT_EXPANDER_DEVICE)
 					sas_unregister_ex_tree(parent->port, child);
-				else
+				else {
+					sas_wait_discover_event_init(parent->port);
 					sas_unregister_dev(parent->port, child);
+					sas_wait_for_discover_event_finish(parent->port);
+				}
 				found = child;
 				break;
 			}
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index c227a8b..c9907ec1 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -38,6 +38,8 @@
 
 #include "../scsi_sas_internal.h"
 
+static DEFINE_IDA(sas_ida);
+
 static struct kmem_cache *sas_task_cache;
 
 struct sas_task *sas_alloc_task(gfp_t flags)
@@ -116,6 +118,7 @@ void sas_hae_reset(struct work_struct *work)
 int sas_register_ha(struct sas_ha_struct *sas_ha)
 {
 	int error = 0;
+	char name[64];
 
 	mutex_init(&sas_ha->disco_mutex);
 	spin_lock_init(&sas_ha->phy_port_lock);
@@ -146,6 +149,22 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
 		goto Undo_ports;
 	}
 
+	snprintf(name, 64, "%s_event_q", dev_name(sas_ha->dev));
+	sas_ha->event_q = create_singlethread_workqueue(name);
+	if (!sas_ha->event_q)
+		goto Undo_ports;
+
+	/*
+	 * sas-disc-xx workqueue run the discover work except
+	 * probe and destruct.
+	 */
+	snprintf(name, 64, "%s_disc_q", dev_name(sas_ha->dev));
+	sas_ha->disc_q = create_singlethread_workqueue(name);
+	if(!sas_ha->disc_q) {
+		destroy_workqueue(sas_ha->event_q);
+		goto Undo_ports;
+	}
+
 	INIT_LIST_HEAD(&sas_ha->eh_done_q);
 	INIT_LIST_HEAD(&sas_ha->eh_ata_q);
 
@@ -181,6 +200,9 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha)
 	__sas_drain_work(sas_ha);
 	mutex_unlock(&sas_ha->drain_mutex);
 
+	destroy_workqueue(sas_ha->event_q);
+	destroy_workqueue(sas_ha->disc_q);
+	ida_simple_remove(&sas_ida, sas_ha->id);
 	return 0;
 }
 
@@ -561,7 +583,6 @@ sas_domain_attach_transport(struct sas_domain_function_template *dft)
 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
 
 /* ---------- SAS Class register/unregister ---------- */
-
 static int __init sas_class_init(void)
 {
 	sas_task_cache = KMEM_CACHE(sas_task, SLAB_HWCACHE_ALIGN);
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 33ce7e5..d5fcae8 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -100,6 +100,67 @@ void sas_free_device(struct kref *kref);
 extern const work_func_t sas_phy_event_fns[PHY_NUM_EVENTS];
 extern const work_func_t sas_port_event_fns[PORT_NUM_EVENTS];
 
+static inline void sas_wait_discover_event_init(struct asd_sas_port *port)
+{
+	if (port) {
+		init_completion(&port->disc.completion);
+		port->disc.wait = 1;
+		port->disc.busy = 0;
+	}
+}
+
+static inline void sas_wait_for_discover_event_finish(
+		struct asd_sas_port *port)
+{
+	if (port && port->disc.busy > 0)
+		wait_for_completion(&port->disc.completion);
+}
+
+static inline void sas_wait_sas_event_init(struct asd_sas_port *port)
+{
+	if (port) {
+		init_completion(&port->completion);
+		kref_init(&port->ref);
+	}
+}
+
+static inline void sas_wait_for_sas_event_finish(
+		struct asd_sas_port *port)
+{
+	if (port && (kref_read(&port->ref) > 1))
+		wait_for_completion(&port->completion);
+}
+
+static inline void sas_busy_port(struct asd_sas_port *port)
+{
+	if (port)
+		kref_get(&port->ref);
+
+	if (port->disc.wait == 1)
+		port->disc.busy++;
+}
+
+static void sas_complete_event(struct kref *kref)
+{
+	struct asd_sas_port *port = container_of(kref, struct asd_sas_port, ref);
+
+	complete(&port->completion);
+}
+
+static inline void sas_unbusy_port(struct asd_sas_port *port)
+{
+	if (!port)
+		return;
+
+	kref_put(&port->ref, sas_complete_event);
+
+	if (port->disc.wait == 1) {
+		complete(&port->disc.completion);
+		port->disc.wait = 0;
+		port->disc.busy = 0;
+	}
+}
+
 #ifdef CONFIG_SCSI_SAS_HOST_SMP
 extern int sas_smp_host_handler(struct Scsi_Host *shost, struct request *req,
 				struct request *rsp);
diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index 9326628..459f852 100644
--- a/drivers/scsi/libsas/sas_port.c
+++ b/drivers/scsi/libsas/sas_port.c
@@ -191,7 +191,9 @@ static void sas_form_port(struct asd_sas_phy *phy)
 	if (si->dft->lldd_port_formed)
 		si->dft->lldd_port_formed(phy);
 
+	sas_wait_sas_event_init(port);
 	sas_discover_event(phy->port, DISCE_DISCOVER_DOMAIN);
+	sas_wait_for_sas_event_finish(port);
 }
 
 /**
@@ -218,7 +220,9 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone)
 		dev->pathways--;
 
 	if (port->num_phys == 1) {
+		sas_wait_sas_event_init(port);
 		sas_unregister_domain_devices(port, gone);
+		sas_wait_for_sas_event_finish(port);
 		sas_port_delete(port->port);
 		port->port = NULL;
 	} else {
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index e6ebad0..be09491 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -240,6 +240,7 @@ static inline void INIT_SAS_WORK(struct sas_work *sw, void (*fn)(struct work_str
 struct sas_discovery_event {
 	struct sas_work work;
 	struct asd_sas_port *port;
+	enum discover_event	type;
 };
 
 static inline struct sas_discovery_event *to_sas_discovery_event(struct work_struct *work)
@@ -256,6 +257,9 @@ struct sas_discovery {
 	u8     eeds_a[8];
 	u8     eeds_b[8];
 	int    max_level;
+	int    wait;
+	int    busy;
+	struct completion completion;
 };
 
 /* The port struct is Class:RW, driver:RO */
@@ -273,6 +277,8 @@ struct asd_sas_port {
 
 	struct sas_work work;
 	int suspended;
+	struct kref ref;
+	struct completion completion;
 
 /* public: */
 	int id;
@@ -387,6 +393,7 @@ struct sas_ha_struct {
 	int		  eh_active;
 	wait_queue_head_t eh_wait_q;
 	struct list_head  eh_dev_q;
+	int       id; /* for create workqueue */
 
 	struct mutex disco_mutex;
 
@@ -396,6 +403,8 @@ struct sas_ha_struct {
 	char *sas_ha_name;
 	struct device *dev;	  /* should be set */
 	struct module *lldd_module; /* should be set */
+	struct workqueue_struct	*event_q;
+	struct workqueue_struct	*disc_q;
 
 	u8 *sas_addr;		  /* must be set */
 	u8 hashed_sas_addr[HASHED_SAS_ADDR_SIZE];
