bcm63xx_enet: correct clock usage

BugLink: https://bugs.launchpad.net/bugs/1790884

commit 9c86b846 upstream.

Check the return code of prepare_enable and change one last instance of
enable only to prepare_enable. Also properly disable and release the
clock in error paths and on remove for enetsw.
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/net/ethernet/broadcom/bcm63xx_enet.c

@@ -1787,7 +1787,9 @@ static int bcm_enet_probe(struct platform_device *pdev)
 		ret = PTR_ERR(priv->mac_clk);
 		goto out;
 	}
-	clk_prepare_enable(priv->mac_clk);
+	ret = clk_prepare_enable(priv->mac_clk);
+	if (ret)
+		goto out_put_clk_mac;
 
 	/* initialize default and fetch platform data */
 	priv->rx_ring_size = BCMENET_DEF_RX_DESC;
@@ -1819,9 +1821,11 @@ static int bcm_enet_probe(struct platform_device *pdev)
 		if (IS_ERR(priv->phy_clk)) {
 			ret = PTR_ERR(priv->phy_clk);
 			priv->phy_clk = NULL;
-			goto out_put_clk_mac;
+			goto out_disable_clk_mac;
 		}
-		clk_prepare_enable(priv->phy_clk);
+		ret = clk_prepare_enable(priv->phy_clk);
+		if (ret)
+			goto out_put_clk_phy;
 	}
 
 	/* do minimal hardware init to be able to probe mii bus */
@@ -1921,13 +1925,16 @@ static int bcm_enet_probe(struct platform_device *pdev)
 out_uninit_hw:
 	/* turn off mdc clock */
 	enet_writel(priv, 0, ENET_MIISC_REG);
-	if (priv->phy_clk) {
+	if (priv->phy_clk)
 		clk_disable_unprepare(priv->phy_clk);
+
+out_put_clk_phy:
+	if (priv->phy_clk)
 		clk_put(priv->phy_clk);
-	}
 
-out_put_clk_mac:
+out_disable_clk_mac:
 	clk_disable_unprepare(priv->mac_clk);
+out_put_clk_mac:
 	clk_put(priv->mac_clk);
 out:
 	free_netdev(dev);
@@ -2772,7 +2779,9 @@ static int bcm_enetsw_probe(struct platform_device *pdev)
 		ret = PTR_ERR(priv->mac_clk);
 		goto out_unmap;
 	}
-	clk_enable(priv->mac_clk);
+	ret = clk_prepare_enable(priv->mac_clk);
+	if (ret)
+		goto out_put_clk;
 
 	priv->rx_chan = 0;
 	priv->tx_chan = 1;
@@ -2793,7 +2802,7 @@ static int bcm_enetsw_probe(struct platform_device *pdev)
 
 	ret = register_netdev(dev);
 	if (ret)
-		goto out_put_clk;
+		goto out_disable_clk;
 
 	netif_carrier_off(dev);
 	platform_set_drvdata(pdev, dev);
@@ -2802,6 +2811,9 @@ static int bcm_enetsw_probe(struct platform_device *pdev)
 
 	return 0;
 
+out_disable_clk:
+	clk_disable_unprepare(priv->mac_clk);
+
 out_put_clk:
 	clk_put(priv->mac_clk);
 
@@ -2833,6 +2845,9 @@ static int bcm_enetsw_remove(struct platform_device *pdev)
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(res->start, resource_size(res));
 
+	clk_disable_unprepare(priv->mac_clk);
+	clk_put(priv->mac_clk);
+
 	free_netdev(dev);
 	return 0;
 }