NET/ixgbe: Fix powering off during shutdown

Prevent ixgbe from putting the adapter into D3 during shutdown except when
we're going to power off the system, since doing that may generally cause
problems with kexec to happen (such problems were observed for igb and
forcedeth).  For this purpose seperate ixgbe_shutdown() from ixgbe_suspend()
and use the appropriate PCI PM callbacks in both of them.
Signed-off-by: N"Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_main.c

@@ -3612,9 +3612,9 @@ static int ixgbe_resume(struct pci_dev *pdev)
 
 	return 0;
 }
-
 #endif /* CONFIG_PM */
-static int ixgbe_suspend(struct pci_dev *pdev, pm_message_t state)
+
+static int __ixgbe_shutdown(struct pci_dev *pdev, bool *enable_wake)
 {
 	struct net_device *netdev = pci_get_drvdata(pdev);
 	struct ixgbe_adapter *adapter = netdev_priv(netdev);
@@ -3673,18 +3673,46 @@ static int ixgbe_suspend(struct pci_dev *pdev, pm_message_t state)
 		pci_enable_wake(pdev, PCI_D3cold, 0);
 	}
 
+	*enable_wake = !!wufc;
+
 	ixgbe_release_hw_control(adapter);
 
 	pci_disable_device(pdev);
 
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int ixgbe_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	int retval;
+	bool wake;
+
+	retval = __ixgbe_shutdown(pdev, &wake);
+	if (retval)
+		return retval;
+
+	if (wake) {
+		pci_prepare_to_sleep(pdev);
+	} else {
+		pci_wake_from_d3(pdev, false);
+		pci_set_power_state(pdev, PCI_D3hot);
+	}
 
 	return 0;
 }
+#endif /* CONFIG_PM */
 
 static void ixgbe_shutdown(struct pci_dev *pdev)
 {
-	ixgbe_suspend(pdev, PMSG_SUSPEND);
+	bool wake;
+
+	__ixgbe_shutdown(pdev, &wake);
+
+	if (system_state == SYSTEM_POWER_OFF) {
+		pci_wake_from_d3(pdev, wake);
+		pci_set_power_state(pdev, PCI_D3hot);
+	}
 }
 
 /**