4.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ursula Braun <redacted>

commit 7831b4ff0d926e0deeaabef9db8800ed069a2757 upstream.

A qeth_card contains a napi_struct linked to the net_device during
device probing. This struct must be deleted when removing the qeth
device, otherwise Panic on oops can occur when qeth devices are
repeatedly removed and added.

Fixes: a1c3ed4c9ca ("qeth: NAPI support for l2 and l3 discipline")
Signed-off-by: Ursula Braun <redacted>
Tested-by: Alexander Klein <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/s390/net/qeth_l2_main.c |    1 +
 drivers/s390/net/qeth_l3_main.c |    1 +
 2 files changed, 2 insertions(+)

--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c

@@ -1051,6 +1051,7 @@ static void qeth_l2_remove_device(struct
 		qeth_l2_set_offline(cgdev);
 
 	if (card->dev) {
+		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
 		card->dev = NULL;
 	}
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c

@@ -3226,6 +3226,7 @@ static void qeth_l3_remove_device(struct
 		qeth_l3_set_offline(cgdev);
 
 	if (card->dev) {
+		netif_napi_del(&card->napi);
 		unregister_netdev(card->dev);
 		card->dev = NULL;
 	}