s390/qeth: detach netdevice while card is offline

When a qeth card is offline, it has no connection to the HW. So none of
our control callbacks can run IO against it, and we can only cache the
input (eg a new MAC address) without providing proper feedback to the
caller. In this context, it seems much more reasonable to simply detach
the netdevice and let the kernel reject any interaction with it.

This also makes all sorts of internal state checks and locking obsolete.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 49 deletions

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 06bd42a846fa..f7c097a613fc 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -193,23 +193,6 @@ const char *qeth_get_cardname_short(struct qeth_card *card)
 	return "n/a";
 }
 
-void qeth_set_recovery_task(struct qeth_card *card)
-{
-	card->recovery_task = current;
-}
-EXPORT_SYMBOL_GPL(qeth_set_recovery_task);
-
-void qeth_clear_recovery_task(struct qeth_card *card)
-{
-	card->recovery_task = NULL;
-}
-EXPORT_SYMBOL_GPL(qeth_clear_recovery_task);
-
-static bool qeth_is_recovery_task(const struct qeth_card *card)
-{
-	return card->recovery_task == current;
-}
-
 void qeth_set_allowed_threads(struct qeth_card *card, unsigned long threads,
 			 int clear_start_mask)
 {
@@ -236,15 +219,6 @@ int qeth_threads_running(struct qeth_card *card, unsigned long threads)
 }
 EXPORT_SYMBOL_GPL(qeth_threads_running);
 
-int qeth_wait_for_threads(struct qeth_card *card, unsigned long threads)
-{
-	if (qeth_is_recovery_task(card))
-		return 0;
-	return wait_event_interruptible(card->wait_q,
-			qeth_threads_running(card, threads) == 0);
-}
-EXPORT_SYMBOL_GPL(qeth_wait_for_threads);
-
 void qeth_clear_working_pool_list(struct qeth_card *card)
 {
 	struct qeth_buffer_pool_entry *pool_entry, *tmp;
@@ -5923,9 +5897,6 @@ int qeth_do_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 	if (!card)
 		return -ENODEV;
 
-	if (!qeth_card_hw_is_reachable(card))
-		return -ENODEV;
-
 	if (card->info.type == QETH_CARD_TYPE_OSN)
 		return -EPERM;
 
@@ -6236,8 +6207,6 @@ int qeth_core_ethtool_get_link_ksettings(struct net_device *netdev,
 	/* Check if we can obtain more accurate information.	 */
 	/* If QUERY_CARD_INFO command is not supported or fails, */
 	/* just return the heuristics that was filled above.	 */
-	if (!qeth_card_hw_is_reachable(card))
-		return -ENODEV;
 	rc = qeth_query_card_info(card, &carrier_info);
 	if (rc == -EOPNOTSUPP) /* for old hardware, return heuristic */
 		return 0;
@@ -6608,10 +6577,7 @@ netdev_features_t qeth_fix_features(struct net_device *dev,
 		features &= ~NETIF_F_TSO;
 	if (!qeth_is_supported6(card, IPA_OUTBOUND_TSO))
 		features &= ~NETIF_F_TSO6;
-	/* if the card isn't up, remove features that require hw changes */
-	if (card->state == CARD_STATE_DOWN ||
-	    card->state == CARD_STATE_RECOVER)
-		features &= ~QETH_HW_FEATURES;
+
 	QETH_DBF_HEX(SETUP, 2, &features, sizeof(features));
 	return features;
 }
@@ -6643,7 +6609,7 @@ netdev_features_t qeth_features_check(struct sk_buff *skb,
 }
 EXPORT_SYMBOL_GPL(qeth_features_check);
 
-int qeth_open_internal(struct net_device *dev)
+int qeth_open(struct net_device *dev)
 {
 	struct qeth_card *card = dev->ml_priv;
 
@@ -6667,19 +6633,6 @@ int qeth_open_internal(struct net_device *dev)
 	local_bh_enable();
 	return 0;
 }
-EXPORT_SYMBOL_GPL(qeth_open_internal);
-
-int qeth_open(struct net_device *dev)
-{
-	struct qeth_card *card = dev->ml_priv;
-
-	QETH_CARD_TEXT(card, 5, "qethope_");
-	if (qeth_wait_for_threads(card, QETH_RECOVER_THREAD)) {
-		QETH_CARD_TEXT(card, 3, "openREC");
-		return -ERESTARTSYS;
-	}
-	return qeth_open_internal(dev);
-}
 EXPORT_SYMBOL_GPL(qeth_open);
 
 int qeth_stop(struct net_device *dev)