diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index b162f7a..40dbaaa 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -1008,6 +1008,8 @@
 static int
 mptsas_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
+	MPT_SCSI_HOST	*hd;
+	MPT_ADAPTER	*ioc;
 	VirtDevice	*vdevice = SCpnt->device->hostdata;
 
 	if (!vdevice || !vdevice->vtarget || vdevice->vtarget->deleted) {
@@ -1016,6 +1018,12 @@
 		return 0;
 	}
 
+	hd = shost_priv(SCpnt->device->host);
+	ioc = hd->ioc;
+
+	if (ioc->sas_discovery_quiesce_io)
+		return SCSI_MLQUEUE_HOST_BUSY;
+
 //	scsi_print_command(SCpnt);
 
 	return mptscsih_qcmd(SCpnt,done);
@@ -3009,6 +3017,7 @@
 	EVENT_DATA_SAS_DISCOVERY *discovery_data)
 {
 	struct mptsas_discovery_event *ev;
+	u32 discovery_status;
 
 	/*
 	 * DiscoveryStatus
@@ -3017,7 +3026,9 @@
 	 * kicks off discovery, and return to zero
 	 * once its completed.
 	 */
-	if (discovery_data->DiscoveryStatus)
+	discovery_status = le32_to_cpu(discovery_data->DiscoveryStatus);
+	ioc->sas_discovery_quiesce_io = discovery_status ? 1 : 0;
+	if (discovery_status)
 		return;
 
 	ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
@@ -3299,12 +3310,22 @@
 	return error;
 }
 
+void
+mptsas_shutdown(struct pci_dev *pdev)
+{
+	MPT_ADAPTER *ioc = pci_get_drvdata(pdev);
+
+	ioc->sas_discovery_quiesce_io = 0;
+}
+
 static void __devexit mptsas_remove(struct pci_dev *pdev)
 {
 	MPT_ADAPTER *ioc = pci_get_drvdata(pdev);
 	struct mptsas_portinfo *p, *n;
 	int i;
 
+	mptsas_shutdown(pdev);
+
 	ioc->sas_discovery_ignore_events = 1;
 	sas_remove_host(ioc->sh);
 
@@ -3342,7 +3363,7 @@
 	.id_table	= mptsas_pci_table,
 	.probe		= mptsas_probe,
 	.remove		= __devexit_p(mptsas_remove),
-	.shutdown	= mptscsih_shutdown,
+	.shutdown	= mptsas_shutdown,
 #ifdef CONFIG_PM
 	.suspend	= mptscsih_suspend,
 	.resume		= mptscsih_resume,