s390/qeth: when thread completes, wake up all waiters

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

[ Upstream commit 1063e432 ]

qeth_wait_for_threads() is potentially called by multiple users, make
sure to notify all of them after qeth_clear_thread_running_bit()
adjusted the thread_running_mask. With no timeout, callers would
otherwise stall.
Signed-off-by: Julian Wiedmann <jwi@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

@@ -952,7 +952,7 @@ void qeth_clear_thread_running_bit(struct qeth_card *card, unsigned long thread)
 	spin_lock_irqsave(&card->thread_mask_lock, flags);
 	card->thread_running_mask &= ~thread;
 	spin_unlock_irqrestore(&card->thread_mask_lock, flags);
-	wake_up(&card->wait_q);
+	wake_up_all(&card->wait_q);
 }
 EXPORT_SYMBOL_GPL(qeth_clear_thread_running_bit);