s390/qeth: free netdevice when removing a card

BugLink: http://bugs.launchpad.net/bugs/1764999

[ Upstream commit 6be68739 ]

On removal, a qeth card's netdevice is currently not properly freed
because the call chain looks as follows:

qeth_core_remove_device(card)
	lx_remove_device(card)
		unregister_netdev(card->dev)
		card->dev = NULL			!!!
	qeth_core_free_card(card)
		if (card->dev)				!!!
			free_netdev(card->dev)

Fix it by free'ing the netdev straight after unregistering. This also
fixes the sysfs-driven layer switch case (qeth_dev_layer2_store()),
where the need to free the current netdevice was not considered at all.

Note that free_netdev() takes care of the netif_napi_del() for us too.

Fixes: 4a71df50 ("qeth: new qeth device driver")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/s390/net/qeth_core_main.c

@@ -4970,8 +4970,6 @@ static void qeth_core_free_card(struct qeth_card *card)
 	QETH_DBF_HEX(SETUP, 2, &card, sizeof(void *));
 	qeth_clean_channel(&card->read);
 	qeth_clean_channel(&card->write);
-	if (card->dev)
-		free_netdev(card->dev);
 	kfree(card->ip_tbd_list);
 	qeth_free_qdio_buffers(card);
 	unregister_service_level(&card->qeth_service_level);

drivers/s390/net/qeth_l2_main.c

@@ -1062,8 +1062,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l2_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}
 	return;

drivers/s390/net/qeth_l3_main.c

@@ -3243,8 +3243,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev)
 		qeth_l3_set_offline(cgdev);
 
 	if (card->dev) {
-		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
+		free_netdev(card->dev);
 		card->dev = NULL;
 	}