Index: sys/dev/scsipi/scsipi_base.c
===================================================================
RCS file: /cvsroot/src/sys/dev/scsipi/scsipi_base.c,v
retrieving revision 1.175
diff -u -p -r1.175 scsipi_base.c
--- sys/dev/scsipi/scsipi_base.c	22 Dec 2016 11:19:21 -0000	1.175
+++ sys/dev/scsipi/scsipi_base.c	3 Jan 2017 07:32:42 -0000
@@ -493,6 +498,12 @@ scsipi_get_xs(struct scsipi_periph *peri
 				periph->periph_flags &= ~PERIPH_RECOVERY_ACTIVE;
 		} else
 			periph->periph_active--;
+		KASSERT(mutex_owned(chan_mtx(periph->periph_channel)));
+		if (periph->periph_active == 0 &&
+		    (periph->periph_flags & PERIPH_WAITDRAIN) != 0) {
+			periph->periph_flags &= ~PERIPH_WAITDRAIN;
+			cv_broadcast(periph_cv_active(periph));
+		}
 		if (lock)
 			mutex_exit(chan_mtx(periph->periph_channel));
 		scsipi_printaddr(periph);
@@ -535,6 +549,8 @@ scsipi_put_xs(struct scsipi_xfer *xs)
 
 	SC_DEBUG(periph, SCSIPI_DB3, ("scsipi_free_xs\n"));
 
+	KASSERT(mutex_owned(chan_mtx(periph->periph_channel)));
+
 	TAILQ_REMOVE(&periph->periph_xferq, xs, device_q);
 	callout_destroy(&xs->xs_callout);
 	pool_put(&scsipi_xfer_pool, xs);
@@ -682,8 +688,10 @@ scsipi_periph_thaw_locked(struct scsipi_
 	}
 #endif
 	if (periph->periph_qfreeze == 0 &&
-	    (periph->periph_flags & PERIPH_WAITING) != 0)
+	    (periph->periph_flags & PERIPH_WAITING) != 0) {
+		periph->periph_flags &= ~PERIPH_WAITING;
 		cv_broadcast(periph_cv_periph(periph));
+	}
 }
 
 void
@@ -767,6 +775,7 @@ scsipi_kill_pending(struct scsipi_periph
 {
 	struct scsipi_channel *chan = periph->periph_channel;
 
+	KASSERT(mutex_owned(chan_mtx(chan)));
 	(*chan->chan_bustype->bustype_kill_pending)(periph);
 	while (periph->periph_active != 0) {
 		periph->periph_flags |= PERIPH_WAITDRAIN;
@@ -1587,10 +1596,12 @@ scsipi_complete(struct scsipi_xfer *xs)
 			 */
 			mo.mo_target = periph->periph_target;
 			mo.mo_lun = periph->periph_lun;
+			mutex_enter(chan_mtx(chan));
 			if (periph->periph_active < periph->periph_openings)
 				mo.mo_openings = periph->periph_active - 1;
 			else
 				mo.mo_openings = periph->periph_openings - 1;
+			mutex_exit(chan_mtx(chan));
 #ifdef DIAGNOSTIC
 			if (mo.mo_openings < 0) {
 				scsipi_printaddr(periph);
@@ -2158,9 +2169,9 @@ scsipi_completion_thread(void *arg)
 			scsipi_adapter_request(chan,
 			    ADAPTER_REQ_GROW_RESOURCES, NULL);
 			scsipi_channel_thaw(chan, 1);
-			if (chan->chan_tflags & SCSIPI_CHANT_GROWRES)
-				kpause("scsizzz", FALSE, hz/10, NULL);
 			mutex_enter(chan_mtx(chan));
+			if (chan->chan_tflags & SCSIPI_CHANT_GROWRES)
+				kpause("scsizzz", FALSE, hz/10, chan_mtx(chan));
 			continue;
 		}
 		if (chan->chan_tflags & SCSIPI_CHANT_KICK) {