stmmac: intel: Fix clock handling on error and remove paths

clk_prepare_enable() might fail, we have to check its returned value.
Besides that we have to call clk_disable_unprepare() on the error and
remove paths. Do above in the dwmac-intel driver.

While at it, remove leftover in stmmac_pci and remove unneeded condition
for NULL-aware clk_unregister_fixed_rate() call.

Fixes: 58da0cf ("net: stmmac: create dwmac-intel.c to contain all Intel platform")
Cc: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -252,6 +252,7 @@ static void common_default_data(struct plat_stmmacenet_data *plat)
 static int intel_mgbe_common_data(struct pci_dev *pdev,
 				  struct plat_stmmacenet_data *plat)
 {
+	int ret;
 	int i;
 
 	plat->clk_csr = 5;
@@ -324,7 +325,12 @@ static int intel_mgbe_common_data(struct pci_dev *pdev,
 		dev_warn(&pdev->dev, "Fail to register stmmac-clk\n");
 		plat->stmmac_clk = NULL;
 	}
-	clk_prepare_enable(plat->stmmac_clk);
+
+	ret = clk_prepare_enable(plat->stmmac_clk);
+	if (ret) {
+		clk_unregister_fixed_rate(plat->stmmac_clk);
+		return ret;
+	}
 
 	/* Set default value for multicast hash bins */
 	plat->multicast_filter_bins = HASH_TABLE_SIZE;
@@ -657,7 +663,13 @@ static int intel_eth_pci_probe(struct pci_dev *pdev,
 	res.wol_irq = pdev->irq;
 	res.irq = pdev->irq;
 
-	return stmmac_dvr_probe(&pdev->dev, plat, &res);
+	ret = stmmac_dvr_probe(&pdev->dev, plat, &res);
+	if (ret) {
+		clk_disable_unprepare(plat->stmmac_clk);
+		clk_unregister_fixed_rate(plat->stmmac_clk);
+	}
+
+	return ret;
 }
 
 /**
@@ -675,8 +687,8 @@ static void intel_eth_pci_remove(struct pci_dev *pdev)
 
 	stmmac_dvr_remove(&pdev->dev);
 
-	if (priv->plat->stmmac_clk)
-		clk_unregister_fixed_rate(priv->plat->stmmac_clk);
+	clk_disable_unprepare(priv->plat->stmmac_clk);
+	clk_unregister_fixed_rate(priv->plat->stmmac_clk);
 
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)

drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c

@@ -217,15 +217,10 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
  */
 static void stmmac_pci_remove(struct pci_dev *pdev)
 {
-	struct net_device *ndev = dev_get_drvdata(&pdev->dev);
-	struct stmmac_priv *priv = netdev_priv(ndev);
 	int i;
 
 	stmmac_dvr_remove(&pdev->dev);
 
-	if (priv->plat->stmmac_clk)
-		clk_unregister_fixed_rate(priv->plat->stmmac_clk);
-
 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 		if (pci_resource_len(pdev, i) == 0)
 			continue;