net: stmmac: Fix WoL for PCI-based setups

WoL won't work in PCI-based setups because we are not saving the PCI EP
state before entering suspend state and not allowing D3 wake.

Fix this by using a wrapper around stmmac_{suspend/resume} which
correctly sets the PCI EP state.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -257,7 +257,7 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
 		return -ENOMEM;
 
 	/* Enable pci device */
-	ret = pcim_enable_device(pdev);
+	ret = pci_enable_device(pdev);
 	if (ret) {
 		dev_err(&pdev->dev, "%s: ERROR: failed to enable device\n",
 			__func__);
@@ -300,9 +300,45 @@ static int stmmac_pci_probe(struct pci_dev *pdev,
 static void stmmac_pci_remove(struct pci_dev *pdev)
 {
 	stmmac_dvr_remove(&pdev->dev);
+	pci_disable_device(pdev);
 }
 
-static SIMPLE_DEV_PM_OPS(stmmac_pm_ops, stmmac_suspend, stmmac_resume);
+static int stmmac_pci_suspend(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int ret;
+
+	ret = stmmac_suspend(dev);
+	if (ret)
+		return ret;
+
+	ret = pci_save_state(pdev);
+	if (ret)
+		return ret;
+
+	pci_disable_device(pdev);
+	pci_wake_from_d3(pdev, true);
+	return 0;
+}
+
+static int stmmac_pci_resume(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int ret;
+
+	pci_restore_state(pdev);
+	pci_set_power_state(pdev, PCI_D0);
+
+	ret = pci_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	pci_set_master(pdev);
+
+	return stmmac_resume(dev);
+}
+
+static SIMPLE_DEV_PM_OPS(stmmac_pm_ops, stmmac_pci_suspend, stmmac_pci_resume);
 
 /* synthetic ID, no official vendor */
 #define PCI_VENDOR_ID_STMMAC 0x700