diff --git a/drivers/net/dsa/mv88e6060.c b/drivers/net/dsa/mv88e6060.c
index 776e965dc9f45c886b5c23456a801d2a26bbc2cd..05b0ca3bf71d72f11515241f0cfac14ea1f2c4a6 100644
--- a/drivers/net/dsa/mv88e6060.c
+++ b/drivers/net/dsa/mv88e6060.c
@@ -21,8 +21,12 @@
 
 static int reg_read(struct dsa_switch *ds, int addr, int reg)
 {
-	return mdiobus_read(to_mii_bus(ds->master_dev),
-			    ds->pd->sw_addr + addr, reg);
+	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
+
+	if (bus == NULL)
+		return -EINVAL;
+
+	return mdiobus_read(bus, ds->pd->sw_addr + addr, reg);
 }
 
 #define REG_READ(addr, reg)					\
@@ -38,8 +42,12 @@ static int reg_read(struct dsa_switch *ds, int addr, int reg)
 
 static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
 {
-	return mdiobus_write(to_mii_bus(ds->master_dev),
-			     ds->pd->sw_addr + addr, reg, val);
+	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
+
+	if (bus == NULL)
+		return -EINVAL;
+
+	return mdiobus_write(bus, ds->pd->sw_addr + addr, reg, val);
 }
 
 #define REG_WRITE(addr, reg, val)				\
diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index d6f6428b27dcc02dbce52a3f0666d58b8ccbf385..a6c90cf5634d899e745f97b763299018d49e049c 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -75,11 +75,14 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg)
 int mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
 {
 	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
 	int ret;
 
+	if (bus == NULL)
+		return -EINVAL;
+
 	mutex_lock(&ps->smi_mutex);
-	ret = __mv88e6xxx_reg_read(to_mii_bus(ds->master_dev),
-				   ds->pd->sw_addr, addr, reg);
+	ret = __mv88e6xxx_reg_read(bus, ds->pd->sw_addr, addr, reg);
 	mutex_unlock(&ps->smi_mutex);
 
 	return ret;
@@ -119,11 +122,14 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,
 int mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
 {
 	struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+	struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
 	int ret;
 
+	if (bus == NULL)
+		return -EINVAL;
+
 	mutex_lock(&ps->smi_mutex);
-	ret = __mv88e6xxx_reg_write(to_mii_bus(ds->master_dev),
-				    ds->pd->sw_addr, addr, reg, val);
+	ret = __mv88e6xxx_reg_write(bus, ds->pd->sw_addr, addr, reg, val);
 	mutex_unlock(&ps->smi_mutex);
 
 	return ret;