net: axienet: stop interface during shutdown

On some platforms, such as iMX6 with PCIe devices, crashes or hangs can
occur if the axienet device continues to perform DMA transfers after
parent devices/busses have been shut down. Shut down the axienet
interface during its shutdown callback in order to avoid this.
Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/xilinx_axienet_main.c

@@ -1797,9 +1797,23 @@ static int axienet_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static void axienet_shutdown(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+
+	rtnl_lock();
+	netif_device_detach(ndev);
+
+	if (netif_running(ndev))
+		dev_close(ndev);
+
+	rtnl_unlock();
+}
+
 static struct platform_driver axienet_driver = {
 	.probe = axienet_probe,
 	.remove = axienet_remove,
+	.shutdown = axienet_shutdown,
 	.driver = {
 		 .name = "xilinx_axienet",
 		 .of_match_table = axienet_of_match,