diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -755,7 +755,7 @@
 {
     int error;
 
-    GIANT_REQUIRED;
+    bus_topo_assert();
 
     error = bus_generic_suspend(dev);
     if (error == 0)
@@ -768,7 +768,7 @@
 acpi_resume(device_t dev)
 {
 
-    GIANT_REQUIRED;
+    bus_topo_assert();
 
     acpi_set_power_children(dev, ACPI_STATE_D0);
 
@@ -779,7 +779,7 @@
 acpi_shutdown(device_t dev)
 {
 
-    GIANT_REQUIRED;
+    bus_topo_assert();
 
     /* Allow children to shutdown first. */
     bus_generic_shutdown(dev);
diff --git a/sys/dev/bhnd/bhnd.c b/sys/dev/bhnd/bhnd.c
--- a/sys/dev/bhnd/bhnd.c
+++ b/sys/dev/bhnd/bhnd.c
@@ -374,7 +374,7 @@
 	u_int				 max_latency;
 	int				 error;
 
-	GIANT_REQUIRED;	/* for newbus */
+	bus_topo_assert();
 
 	if (device_get_parent(child) != dev)
 		return (EINVAL);
@@ -490,7 +490,7 @@
 	struct bhnd_resource	*r;
 	device_t		 pmu_dev;
 
-	GIANT_REQUIRED;	/* for newbus */
+	bus_topo_assert();
 
 	sc = device_get_softc(dev);
 
diff --git a/sys/dev/bhnd/bhnd_subr.c b/sys/dev/bhnd/bhnd_subr.c
--- a/sys/dev/bhnd/bhnd_subr.c
+++ b/sys/dev/bhnd/bhnd_subr.c
@@ -2185,8 +2185,7 @@
 	device_t	nvram;
 	device_t	parent;
 
-        /* Make sure we're holding Giant for newbus */
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	/* Look for a directly-attached NVRAM child */
 	if ((nvram = device_find_child(dev, "bhnd_nvram", -1)) != NULL)
diff --git a/sys/dev/hid/hidbus.c b/sys/dev/hid/hidbus.c
--- a/sys/dev/hid/hidbus.c
+++ b/sys/dev/hid/hidbus.c
@@ -544,7 +544,7 @@
 	device_t *children, child;
 	int ccount, i;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	/* Get a list of all hidbus children */
 	if (device_get_children(bus, &children, &ccount) != 0)
@@ -724,7 +724,7 @@
 	bool is_bus;
 	int error;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	is_bus = device_get_devclass(dev) == hidbus_devclass;
 	bus = is_bus ? dev : device_get_parent(dev);
diff --git a/sys/dev/hid/hmt.c b/sys/dev/hid/hmt.c
--- a/sys/dev/hid/hmt.c
+++ b/sys/dev/hid/hmt.c
@@ -869,7 +869,7 @@
 	device_t hconf;
 	int  err;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	/* Find touchpad's configuration TLC */
 	hconf = hidbus_find_child(device_get_parent(sc->dev),
@@ -886,7 +886,7 @@
 	if (device_get_devclass(hconf) != hconf_devclass)
 		return (ENXIO);
 
-	/* hconf_set_input_mode can drop the Giant while sleeping */
+	/* hconf_set_input_mode can drop the the topo lock while sleeping */
 	device_busy(hconf);
 	err = hconf_set_input_mode(hconf, mode);
 	device_unbusy(hconf);
diff --git a/sys/dev/mii/mii.c b/sys/dev/mii/mii.c
--- a/sys/dev/mii/mii.c
+++ b/sys/dev/mii/mii.c
@@ -377,6 +377,8 @@
 	int bmsr, first, i, nchildren, phymax, phymin, rv;
 	uint32_t phymask;
 
+	bus_topo_assert();
+
 	if (phyloc != MII_PHY_ANY && offloc != MII_OFFSET_ANY) {
 		printf("%s: phyloc and offloc specified\n", __func__);
 		return (EINVAL);
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -867,6 +867,13 @@
 
 DEFINE_CLASS(null, null_methods, 0);
 
+void
+bus_topo_assert()
+{
+
+	GIANT_REQUIRED;	
+}
+
 struct mtx *
 bus_topo_mtx(void)
 {
@@ -2102,7 +2109,7 @@
 	/* We should preserve the devclass (or lack of) set by the bus. */
 	int hasclass = (child->devclass != NULL);
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	dc = dev->devclass;
 	if (!dc)
@@ -2920,7 +2927,7 @@
 {
 	int error;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	if (dev->state >= DS_ALIVE)
 		return (-1);
@@ -2954,7 +2961,7 @@
 {
 	int error;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	error = device_probe(dev);
 	if (error == -1)
@@ -3052,7 +3059,7 @@
 {
 	int error;
 
-	GIANT_REQUIRED;
+	bus_topo_assert();
 
 	PDEBUG(("%s", DEVICENAME(dev)));
 	if (dev->busy > 0)
diff --git a/sys/sys/bus.h b/sys/sys/bus.h
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -745,6 +745,7 @@
 void bus_topo_lock(void);
 void bus_topo_unlock(void);
 struct mtx * bus_topo_mtx(void);
+void bus_topo_assert(void);
 
 /**
  * Shorthands for constructing method tables.