Index: sys/dev/mps/mps_sas.c
===================================================================
--- sys/dev/mps/mps_sas.c
+++ sys/dev/mps/mps_sas.c
@@ -2220,18 +2220,6 @@
 		}
 	}
 
-	/*
-	 * If this is a Start Stop Unit command and it was issued by the driver
-	 * during shutdown, decrement the refcount to account for all of the
-	 * commands that were sent.  All SSU commands should be completed before
-	 * shutdown completes, meaning SSU_refcount will be 0 after SSU_started
-	 * is TRUE.
-	 */
-	if (sc->SSU_started && (csio->cdb_io.cdb_bytes[0] == START_STOP_UNIT)) {
-		mps_dprint(sc, MPS_INFO, "Decrementing SSU count.\n");
-		sc->SSU_refcount--;
-	}
-
 	/* Take the fast path to completion */
 	if (cm->cm_reply == NULL) {
 		if (mpssas_get_ccbstatus(ccb) == CAM_REQ_INPROG) {
Index: sys/dev/mps/mps_sas_lsi.c
===================================================================
--- sys/dev/mps/mps_sas_lsi.c
+++ sys/dev/mps/mps_sas_lsi.c
@@ -1117,13 +1117,13 @@
 	target_id_t targetid;
 	struct mpssas_target *target;
 	char path_str[64];
-	struct timeval cur_time, start_time;
 
 	/*
-	 * For each target, issue a StartStopUnit command to stop the device.
+	 * Disable interrupts now because shutdown is in progress and don't want
+	 * to rely on ISR to complete these. So polling must be done here as
+	 * well.
 	 */
-	sc->SSU_started = TRUE;
-	sc->SSU_refcount = 0;
+	mps_mask_intr(sc);
 	for (targetid = 0; targetid < sc->max_devices; targetid++) {
 		target = &sassc->targets[targetid];
 		if (target->handle == 0x0) {
@@ -1157,12 +1157,9 @@
 			    "handle %d\n", path_str, target->handle);
 			
 			/*
-			 * Issue a START STOP UNIT command for the target.
-			 * Increment the SSU counter to be used to count the
-			 * number of required replies.
+			 * Issue a START STOP UNIT command for the target and
+			 * poll for completion.
 			 */
-			mps_dprint(sc, MPS_INFO, "Incrementing SSU count\n");
-			sc->SSU_refcount++;
 			ccb->ccb_h.target_id =
 			    xpt_path_target_id(ccb->ccb_h.path);
 			ccb->ccb_h.ppriv_ptr1 = sassc;
@@ -1175,27 +1172,9 @@
 			    /*immediate*/FALSE,
 			    MPS_SENSE_LEN,
 			    /*timeout*/10000);
-			xpt_action(ccb);
+			xpt_polled_action(ccb);
 		}
 	}
-
-	/*
-	 * Wait until all of the SSU commands have completed or time has
-	 * expired (60 seconds).  Pause for 100ms each time through.  If any
-	 * command times out, the target will be reset in the SCSI command
-	 * timeout routine.
-	 */
-	getmicrotime(&start_time);
-	while (sc->SSU_refcount) {
-		pause("mpswait", hz/10);
-		
-		getmicrotime(&cur_time);
-		if ((cur_time.tv_sec - start_time.tv_sec) > 60) {
-			mps_dprint(sc, MPS_FAULT, "Time has expired waiting "
-			    "for SSU commands to complete.\n");
-			break;
-		}
-	}
 }
 
 static void
@@ -1214,9 +1193,7 @@
 	    path_str);
 
 	/*
-	 * Nothing more to do except free the CCB and path.  If the command
-	 * timed out, an abort reset, then target reset will be issued during
-	 * the SCSI Command process.
+	 * Nothing more to do except free the CCB and path.
 	 */
 	xpt_free_path(done_ccb->ccb_h.path);
 	xpt_free_ccb(done_ccb);
Index: sys/dev/mps/mpsvar.h
===================================================================
--- sys/dev/mps/mpsvar.h
+++ sys/dev/mps/mpsvar.h
@@ -421,10 +421,6 @@
 
 	char				exclude_ids[80];
 	struct timeval			lastfail;
-
-	/* StartStopUnit command handling at shutdown */
-	uint32_t			SSU_refcount;
-	uint8_t				SSU_started;
 };
 
 struct mps_config_params {