diff --git a/sys/dev/iscsi/iscsi.c b/sys/dev/iscsi/iscsi.c
--- a/sys/dev/iscsi/iscsi.c
+++ b/sys/dev/iscsi/iscsi.c
@@ -44,11 +44,13 @@
 #include <sys/mbuf.h>
 #include <sys/mutex.h>
 #include <sys/module.h>
+#include <sys/reboot.h>
 #include <sys/socket.h>
 #include <sys/sockopt.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/sx.h>
+
 #include <vm/uma.h>
 
 #include <cam/cam.h>
@@ -2711,10 +2713,10 @@
 }
 
 static void
-iscsi_shutdown_post(struct iscsi_softc *sc)
+iscsi_shutdown_post_sync(struct iscsi_softc *sc, int howto)
 {
 
-	if (!KERNEL_PANICKED()) {
+	if ((howto & RB_NOSYNC) == 0) {
 		ISCSI_DEBUG("removing all sessions due to shutdown");
 		iscsi_terminate_sessions(sc);
 	}
@@ -2751,7 +2753,7 @@
 	 * cam_periph_runccb().
 	 */
 	sc->sc_shutdown_post_eh = EVENTHANDLER_REGISTER(shutdown_post_sync,
-	    iscsi_shutdown_post, sc, SHUTDOWN_PRI_DEFAULT - 1);
+	    iscsi_shutdown_post_sync, sc, SHUTDOWN_PRI_DEFAULT - 1);
 
 	return (0);
 }
diff --git a/sys/dev/pst/pst-iop.c b/sys/dev/pst/pst-iop.c
--- a/sys/dev/pst/pst-iop.c
+++ b/sys/dev/pst/pst-iop.c
@@ -432,7 +432,7 @@
     int status, timeout = 10000;
 
     mtx_lock(&sc->mtx);
-    if (!(sc->reg->oqueue_intr_mask & 0x08)) {
+    if ((sc->reg->oqueue_intr_mask & I20_OUT_INTR_QUEUE) == 0) {
         msg->transaction_context = (u_int32_t)&request;
         msg->initiator_context = (u_int32_t)iop_done;
         sc->reg->iqueue = mfa;
diff --git a/sys/dev/pst/pst-raid.c b/sys/dev/pst/pst-raid.c
--- a/sys/dev/pst/pst-raid.c
+++ b/sys/dev/pst/pst-raid.c
@@ -73,7 +73,7 @@
 static disk_strategy_t pststrategy;
 static int pst_probe(device_t);
 static int pst_attach(device_t);
-static int pst_shutdown(device_t);
+static void pst_shutdown_post_sync(device_t, int);
 static void pst_start(struct pst_softc *);
 static void pst_done(struct iop_softc *, u_int32_t, struct i2o_single_reply *);
 static int pst_rw(struct pst_request *);
@@ -170,18 +170,23 @@
 	   name, psc->info->capacity/(512*255*63), 255, 63,
 	   device_get_nameunit(psc->iop->dev));
 
-    EVENTHANDLER_REGISTER(shutdown_post_sync, pst_shutdown,
+    EVENTHANDLER_REGISTER(shutdown_post_sync, pst_shutdown_post_sync,
 			  dev, SHUTDOWN_PRI_FIRST);
     return 0;
 }
 
-static int
-pst_shutdown(device_t dev)
+static void
+pst_shutdown_post_sync(device_t dev, int howto __unused)
 {
     struct pst_softc *psc = device_get_softc(dev);
     struct i2o_bsa_cache_flush_message *msg;
     int mfa;
 
+    if (SCHEDULER_STOPPED()) {
+	/* Request polled shutdown. */
+	psc->reg->oqueue_intr_mask = 0xffffffff;
+    }
+
     mfa = iop_get_mfa(psc->iop);
     msg = (struct i2o_bsa_cache_flush_message *)(psc->iop->ibase + mfa);
     bzero(msg, sizeof(struct i2o_bsa_cache_flush_message));
@@ -194,7 +199,6 @@
     msg->control_flags = 0x0; /* 0x80 = post progress reports */
     if (iop_queue_wait_msg(psc->iop, mfa, (struct i2o_basic_message *)msg))
 	printf("pst: shutdown failed!\n");
-    return 0;
 }
 
 static void
diff --git a/sys/geom/journal/g_journal.c b/sys/geom/journal/g_journal.c
--- a/sys/geom/journal/g_journal.c
+++ b/sys/geom/journal/g_journal.c
@@ -39,6 +39,7 @@
 #include <sys/mount.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/reboot.h>
 #include <sys/sbuf.h>
 #include <sys/sched.h>
 #include <sys/sysctl.h>
@@ -2655,13 +2656,14 @@
 static eventhandler_tag g_journal_event_lowmem = NULL;
 
 static void
-g_journal_shutdown(void *arg, int howto __unused)
+g_journal_shutdown_post_sync(void *arg, int howto)
 {
 	struct g_class *mp;
 	struct g_geom *gp, *gp2;
 
-	if (KERNEL_PANICKED())
+	if ((howto & RB_NOSYNC) != 0)
 		return;
+
 	mp = arg;
 	g_topology_lock();
 	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
@@ -2738,7 +2740,7 @@
 		    (g_journal_cache_limit / 100) * g_journal_cache_switch;
 	}
 	g_journal_event_shutdown = EVENTHANDLER_REGISTER(shutdown_post_sync,
-	    g_journal_shutdown, mp, EVENTHANDLER_PRI_FIRST);
+	    g_journal_shutdown_post_sync, mp, EVENTHANDLER_PRI_FIRST);
 	if (g_journal_event_shutdown == NULL)
 		GJ_DEBUG(0, "Warning! Cannot register shutdown event.");
 	g_journal_event_lowmem = EVENTHANDLER_REGISTER(vm_lowmem,
diff --git a/sys/geom/mirror/g_mirror.c b/sys/geom/mirror/g_mirror.c
--- a/sys/geom/mirror/g_mirror.c
+++ b/sys/geom/mirror/g_mirror.c
@@ -39,6 +39,7 @@
 #include <sys/malloc.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/reboot.h>
 #include <sys/sbuf.h>
 #include <sys/sched.h>
 #include <sys/sx.h>
@@ -3546,7 +3547,7 @@
 	struct g_mirror_softc *sc;
 	int error;
 
-	if (KERNEL_PANICKED())
+	if ((howto & RB_NOSYNC) != 0)
 		return;
 
 	mp = arg;
diff --git a/sys/geom/raid/g_raid.c b/sys/geom/raid/g_raid.c
--- a/sys/geom/raid/g_raid.c
+++ b/sys/geom/raid/g_raid.c
@@ -38,6 +38,7 @@
 #include <sys/module.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/reboot.h>
 #include <sys/sbuf.h>
 #include <sys/sched.h>
 #include <sys/sysctl.h>
@@ -2457,6 +2458,9 @@
 	struct g_raid_softc *sc;
 	struct g_raid_volume *vol;
 
+	if ((howto & RB_NOSYNC) != 0)
+		return;
+
 	mp = arg;
 	g_topology_lock();
 	g_raid_shutdown = 1;
diff --git a/sys/geom/raid3/g_raid3.c b/sys/geom/raid3/g_raid3.c
--- a/sys/geom/raid3/g_raid3.c
+++ b/sys/geom/raid3/g_raid3.c
@@ -38,6 +38,7 @@
 #include <sys/module.h>
 #include <sys/mutex.h>
 #include <sys/proc.h>
+#include <sys/reboot.h>
 #include <sys/sbuf.h>
 #include <sys/sched.h>
 #include <sys/sysctl.h>
@@ -3573,6 +3574,9 @@
 	struct g_raid3_softc *sc;
 	int error;
 
+	if ((howto & RB_NOSYNC) != 0)
+		return;
+
 	mp = arg;
 	g_topology_lock();
 	g_raid3_shutdown = 1;