diff --git a/drivers/net/ethernet/agere/et131x.c b/drivers/net/ethernet/agere/et131x.c
index 5fab589b3ddf6..3d9220f9c9fe7 100644
--- a/drivers/net/ethernet/agere/et131x.c
+++ b/drivers/net/ethernet/agere/et131x.c
@@ -3982,8 +3982,7 @@ static int et131x_pci_setup(struct pci_dev *pdev,
 	}
 
 	adapter->mii_bus->name = "et131x_eth_mii";
-	snprintf(adapter->mii_bus->id, MII_BUS_ID_SIZE, "%x",
-		 (adapter->pdev->bus->number << 8) | adapter->pdev->devfn);
+	snprintf(adapter->mii_bus->id, MII_BUS_ID_SIZE, "%x", pci_dev_id(adapter->pdev));
 	adapter->mii_bus->priv = netdev;
 	adapter->mii_bus->read = et131x_mdio_read;
 	adapter->mii_bus->write = et131x_mdio_write;
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 5ef073a79ce94..7f956cf36337e 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -1539,8 +1539,7 @@ static int tg3_mdio_init(struct tg3 *tp)
 		return -ENOMEM;
 
 	tp->mdio_bus->name     = "tg3 mdio bus";
-	snprintf(tp->mdio_bus->id, MII_BUS_ID_SIZE, "%x",
-		 (tp->pdev->bus->number << 8) | tp->pdev->devfn);
+	snprintf(tp->mdio_bus->id, MII_BUS_ID_SIZE, "%x", pci_dev_id(tp->pdev));
 	tp->mdio_bus->priv     = tp;
 	tp->mdio_bus->parent   = &tp->pdev->dev;
 	tp->mdio_bus->read     = &tg3_mdio_read;
diff --git a/drivers/net/ethernet/smsc/smsc9420.c b/drivers/net/ethernet/smsc/smsc9420.c
index 3b26f1d86beba..e1c4a11c1f181 100644
--- a/drivers/net/ethernet/smsc/smsc9420.c
+++ b/drivers/net/ethernet/smsc/smsc9420.c
@@ -1144,8 +1144,7 @@ static int smsc9420_mii_init(struct net_device *dev)
 		goto err_out_1;
 	}
 	pd->mii_bus->name = DRV_MDIONAME;
-	snprintf(pd->mii_bus->id, MII_BUS_ID_SIZE, "%x",
-		(pd->pdev->bus->number << 8) | pd->pdev->devfn);
+	snprintf(pd->mii_bus->id, MII_BUS_ID_SIZE, "%x", pci_dev_id(pd->pdev));
 	pd->mii_bus->priv = pd;
 	pd->mii_bus->read = smsc9420_mii_read;
 	pd->mii_bus->write = smsc9420_mii_write;
diff --git a/drivers/net/ethernet/toshiba/tc35815.c b/drivers/net/ethernet/toshiba/tc35815.c
index b50be67b398b1..14cf6ecf6d0df 100644
--- a/drivers/net/ethernet/toshiba/tc35815.c
+++ b/drivers/net/ethernet/toshiba/tc35815.c
@@ -667,8 +667,7 @@ static int tc_mii_init(struct net_device *dev)
 	lp->mii_bus->name = "tc35815_mii_bus";
 	lp->mii_bus->read = tc_mdio_read;
 	lp->mii_bus->write = tc_mdio_write;
-	snprintf(lp->mii_bus->id, MII_BUS_ID_SIZE, "%x",
-		 (lp->pci_dev->bus->number << 8) | lp->pci_dev->devfn);
+	snprintf(lp->mii_bus->id, MII_BUS_ID_SIZE, "%x", pci_dev_id(lp->pci_dev));
 	lp->mii_bus->priv = dev;
 	lp->mii_bus->parent = &lp->pci_dev->dev;
 	err = mdiobus_register(lp->mii_bus);
diff --git a/drivers/net/ethernet/wangxun/ngbe/ngbe_mdio.c b/drivers/net/ethernet/wangxun/ngbe/ngbe_mdio.c
index cc2f325a52f78..fe20f02ecb3aa 100644
--- a/drivers/net/ethernet/wangxun/ngbe/ngbe_mdio.c
+++ b/drivers/net/ethernet/wangxun/ngbe/ngbe_mdio.c
@@ -266,8 +266,7 @@ int ngbe_mdio_init(struct wx *wx)
 		mii_bus->write_c45 = ngbe_phy_write_reg_mdi_c45;
 	}
 
-	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "ngbe-%x",
-		 (pdev->bus->number << 8) | pdev->devfn);
+	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "ngbe-%x", pci_dev_id(pdev));
 	ret = devm_mdiobus_register(&pdev->dev, mii_bus);
 	if (ret)
 		return ret;