diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 98af5c3..ee17556 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -220,6 +220,8 @@
 static void hpsa_wait_for_mode_change_ack(struct ctlr_info *h);
 #define BOARD_NOT_READY 0
 #define BOARD_READY 1
+static void hpsa_drain_commands(struct ctlr_info *h);
+static void hpsa_flush_cache(struct ctlr_info *h);
 
 static inline struct ctlr_info *sdev_to_hba(struct scsi_device *sdev)
 {
@@ -5025,6 +5027,23 @@
 	writel(dma_prefetch, h->vaddr + I2O_DMA1_CFG);
 }
 
+static void hpsa_wait_for_clear_event_notify_ack(struct ctlr_info *h)
+{
+	int i;
+	u32 doorbell_value;
+	unsigned long flags;
+	/* wait until the clear_event_notify bit 6 is cleared by controller. */
+	for (i = 0; i < MAX_CONFIG_WAIT; i++) {
+		spin_lock_irqsave(&h->lock, flags);
+		doorbell_value = readl(h->vaddr + SA5_DOORBELL);
+		spin_unlock_irqrestore(&h->lock, flags);
+		if (!(doorbell_value & DOORBELL_CLEAR_EVENTS))
+			break;
+		/* delay and try again */
+		msleep(20);
+	}
+}
+
 static void hpsa_wait_for_mode_change_ack(struct ctlr_info *h)
 {
 	int i;
@@ -5401,6 +5420,79 @@
 	h->last_heartbeat_timestamp = now;
 }
 
+static int hpsa_kickoff_rescan(struct ctlr_info *h)
+{
+	int i;
+	char *event_type;
+
+	/* Ask the controller to clear the events we're handling. */
+	if (h->transMethod & (CFGTBL_Trans_io_accel1) &&
+		(h->events & HPSA_EVENT_NOTIFY_ACCEL_IO_PATH_STATE_CHANGE ||
+		 h->events & HPSA_EVENT_NOTIFY_ACCEL_IO_PATH_CONFIG_CHANGE)) {
+
+		if (h->events & HPSA_EVENT_NOTIFY_ACCEL_IO_PATH_STATE_CHANGE)
+			event_type = "state change";
+		if (h->events & HPSA_EVENT_NOTIFY_ACCEL_IO_PATH_CONFIG_CHANGE)
+			event_type = "configuration change";
+		/* Stop sending new RAID offload reqs via the IO accelerator */
+		scsi_block_requests(h->scsi_host);
+		for (i = 0; i < h->ndevices; i++)
+			h->dev[i]->offload_enabled = 0;
+		hpsa_drain_commands(h);
+		/* Set 'accelerator path config change' bit */
+		dev_warn(&h->pdev->dev,
+			"Acknowledging event: 0x%08x (HP SSD Smart Path %s)\n",
+			h->events, event_type);
+		writel(h->events, &(h->cfgtable->clear_event_notify));
+		/* Set the "clear event notify field update" bit 6 */
+		writel(DOORBELL_CLEAR_EVENTS, h->vaddr + SA5_DOORBELL);
+		/* Wait until ctlr clears 'clear event notify field', bit 6 */
+		hpsa_wait_for_clear_event_notify_ack(h);
+		scsi_unblock_requests(h->scsi_host);
+	} else {
+		/* Acknowledge controller notification events. */
+		writel(h->events, &(h->cfgtable->clear_event_notify));
+		writel(DOORBELL_CLEAR_EVENTS, h->vaddr + SA5_DOORBELL);
+		hpsa_wait_for_clear_event_notify_ack(h);
+#if 0
+		writel(CFGTBL_ChangeReq, h->vaddr + SA5_DOORBELL);
+		hpsa_wait_for_mode_change_ack(h);
+#endif
+	}
+
+	/* Something in the device list may have changed to trigger
+	 * the event, so do a rescan.
+	 */
+	hpsa_scan_start(h->scsi_host);
+	/* release reference taken on scsi host in check_controller_events */
+	scsi_host_put(h->scsi_host);
+	return 0;
+}
+
+/* Check a register on the controller to see if there are configuration
+ * changes (added/changed/removed logical drives, etc.) which mean that
+ * we should rescan the controller for devices.  If so, add the controller
+ * to the list of controllers needing to be rescanned, and gets a
+ * reference to the associated scsi_host.
+ */
+static void hpsa_ctlr_needs_rescan(struct ctlr_info *h)
+{
+	if (!(h->fw_support & MISC_FW_EVENT_NOTIFY))
+		return;
+
+	h->events = readl(&(h->cfgtable->event_notify));
+	if (!h->events)
+		return;
+
+	/*
+	 * Take a reference on scsi host for the duration of the scan
+	 * Release in hpsa_kickoff_rescan().  No lock needed for scan_list
+	 * as only a single thread accesses this list.
+	 */
+	scsi_host_get(h->scsi_host);
+	hpsa_kickoff_rescan(h);
+}
+
 static void hpsa_monitor_ctlr_worker(struct work_struct *work)
 {
 	unsigned long flags;
@@ -5409,6 +5501,7 @@
 	detect_controller_lockup(h);
 	if (h->lockup_detected)
 		return;
+	hpsa_ctlr_needs_rescan(h);
 	spin_lock_irqsave(&h->lock, flags);
 	if (h->remove_in_progress) {
 		spin_unlock_irqrestore(&h->lock, flags);
@@ -5950,6 +6043,21 @@
 	kfree(h->blockFetchTable);
 }
 
+static void hpsa_drain_commands(struct ctlr_info *h)
+{
+	int cmds_out;
+	unsigned long flags;
+
+	do { /* wait for all outstanding commands to drain out */
+		spin_lock_irqsave(&h->lock, flags);
+		cmds_out = h->commands_outstanding;
+		spin_unlock_irqrestore(&h->lock, flags);
+		if (cmds_out <= 0)
+			break;
+		msleep(100);
+	} while (1);
+}
+
 /*
  *  This is it.  Register the PCI driver information for the cards we control
  *  the OS will call our registered routines when it finds one of our cards.