3 files changed, 64 insertions, 2 deletions

diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index e04f6d6f5aff..22bfc025ae81 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -123,6 +123,8 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
 	INIT_LIST_HEAD(&sas_ha->defer_q);
 	INIT_LIST_HEAD(&sas_ha->eh_dev_q);
 
+	sas_ha->event_thres = SAS_PHY_SHUTDOWN_THRES;
+
 	error = sas_register_phys(sas_ha);
 	if (error) {
 		printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
@@ -557,14 +559,43 @@ EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
 
 struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy)
 {
+	struct asd_sas_event *event;
 	gfp_t flags = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
+	struct sas_ha_struct *sas_ha = phy->ha;
+	struct sas_internal *i =
+		to_sas_internal(sas_ha->core.shost->transportt);
+
+	event = kmem_cache_zalloc(sas_event_cache, flags);
+	if (!event)
+		return NULL;
 
-	return kmem_cache_zalloc(sas_event_cache, flags);
+	atomic_inc(&phy->event_nr);
+
+	if (atomic_read(&phy->event_nr) > phy->ha->event_thres) {
+		if (i->dft->lldd_control_phy) {
+			if (cmpxchg(&phy->in_shutdown, 0, 1) == 0) {
+				sas_printk("The phy%02d bursting events, shut it down.\n",
+					phy->id);
+				sas_notify_phy_event(phy, PHYE_SHUTDOWN);
+			}
+		} else {
+			/* Do not support PHY control, stop allocating events */
+			WARN_ONCE(1, "PHY control not supported.\n");
+			kmem_cache_free(sas_event_cache, event);
+			atomic_dec(&phy->event_nr);
+			event = NULL;
+		}
+	}
+
+	return event;
 }
 
 void sas_free_event(struct asd_sas_event *event)
 {
+	struct asd_sas_phy *phy = event->phy;
+
 	kmem_cache_free(sas_event_cache, event);
+	atomic_dec(&phy->event_nr);
 }
 
 /* ---------- SAS Class register/unregister ---------- */
diff --git a/drivers/scsi/libsas/sas_phy.c b/drivers/scsi/libsas/sas_phy.c
index 59f82929b0a3..bf3e1b979ca6 100644
--- a/drivers/scsi/libsas/sas_phy.c
+++ b/drivers/scsi/libsas/sas_phy.c
@@ -35,6 +35,7 @@ static void sas_phye_loss_of_signal(struct work_struct *work)
 	struct asd_sas_event *ev = to_asd_sas_event(work);
 	struct asd_sas_phy *phy = ev->phy;
 
+	phy->in_shutdown = 0;
 	phy->error = 0;
 	sas_deform_port(phy, 1);
 }
@@ -44,6 +45,7 @@ static void sas_phye_oob_done(struct work_struct *work)
 	struct asd_sas_event *ev = to_asd_sas_event(work);
 	struct asd_sas_phy *phy = ev->phy;
 
+	phy->in_shutdown = 0;
 	phy->error = 0;
 }
 
@@ -105,6 +107,28 @@ static void sas_phye_resume_timeout(struct work_struct *work)
 }
 
 
+static void sas_phye_shutdown(struct work_struct *work)
+{
+	struct asd_sas_event *ev = to_asd_sas_event(work);
+	struct asd_sas_phy *phy = ev->phy;
+	struct sas_ha_struct *sas_ha = phy->ha;
+	struct sas_internal *i =
+		to_sas_internal(sas_ha->core.shost->transportt);
+
+	if (phy->enabled) {
+		int ret;
+
+		phy->error = 0;
+		phy->enabled = 0;
+		ret = i->dft->lldd_control_phy(phy, PHY_FUNC_DISABLE, NULL);
+		if (ret)
+			sas_printk("lldd disable phy%02d returned %d\n",
+				phy->id, ret);
+	} else
+		sas_printk("phy%02d is not enabled, cannot shutdown\n",
+			phy->id);
+}
+
 /* ---------- Phy class registration ---------- */
 
 int sas_register_phys(struct sas_ha_struct *sas_ha)
@@ -116,6 +140,7 @@ int sas_register_phys(struct sas_ha_struct *sas_ha)
 		struct asd_sas_phy *phy = sas_ha->sas_phy[i];
 
 		phy->error = 0;
+		atomic_set(&phy->event_nr, 0);
 		INIT_LIST_HEAD(&phy->port_phy_el);
 
 		phy->port = NULL;
@@ -151,5 +176,5 @@ const work_func_t sas_phy_event_fns[PHY_NUM_EVENTS] = {
 	[PHYE_OOB_ERROR] = sas_phye_oob_error,
 	[PHYE_SPINUP_HOLD] = sas_phye_spinup_hold,
 	[PHYE_RESUME_TIMEOUT] = sas_phye_resume_timeout,
-
+	[PHYE_SHUTDOWN] = sas_phye_shutdown,
 };
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index ee1b25299dd6..de8f043475c2 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -75,6 +75,7 @@ enum phy_event {
 	PHYE_OOB_ERROR,
 	PHYE_SPINUP_HOLD,             /* hot plug SATA, no COMWAKE sent */
 	PHYE_RESUME_TIMEOUT,
+	PHYE_SHUTDOWN,
 	PHY_NUM_EVENTS,
 };
 
@@ -311,12 +312,15 @@ static inline void INIT_SAS_EVENT(struct asd_sas_event *ev,
 	ev->event = event;
 }
 
+#define SAS_PHY_SHUTDOWN_THRES   1024
 
 /* The phy pretty much is controlled by the LLDD.
  * The class only reads those fields.
  */
 struct asd_sas_phy {
 /* private: */
+	atomic_t event_nr;
+	int in_shutdown;
 	int error;
 	int suspended;
 
@@ -404,6 +408,8 @@ struct sas_ha_struct {
 
 	struct list_head eh_done_q;  /* complete via scsi_eh_flush_done_q */
 	struct list_head eh_ata_q; /* scmds to promote from sas to ata eh */
+
+	int event_thres;
 };
 
 #define SHOST_TO_SAS_HA(_shost) (*(struct sas_ha_struct **)(_shost)->hostdata)