diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 48ea0004a56d..f07632da815e 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -1334,6 +1334,16 @@ static int __match_queue_device_with_qid(struct device *dev, void *data)
 	return is_queue_dev(dev) && to_ap_queue(dev)->qid == (int)(long) data;
 }
 
+/*
+ * Helper function to be used with bus_find_dev
+ * matches any queue device with given queue id
+ */
+static int __match_queue_device_with_queue_id(struct device *dev, void *data)
+{
+	return is_queue_dev(dev)
+		&& AP_QID_QUEUE(to_ap_queue(dev)->qid) == (int)(long) data;
+}
+
 /*
  * Helper function for ap_scan_bus().
  * Does the scan bus job for the given adapter id.
@@ -1434,8 +1444,13 @@ static void _ap_scan_bus_adapter(int id)
 				borked = aq->state == AP_STATE_BORKED;
 				spin_unlock_bh(&aq->lock);
 			}
-			if (borked)	/* Remove broken device */
+			if (borked) {
+				/* Remove broken device */
+				AP_DBF(DBF_DEBUG,
+				       "removing broken queue=%02x.%04x\n",
+				       id, dom);
 				device_unregister(dev);
+			}
 			put_device(dev);
 			continue;
 		}
@@ -1505,7 +1520,7 @@ static void ap_scan_bus(struct work_struct *unused)
 		struct device *dev =
 			bus_find_device(&ap_bus_type, NULL,
 					(void *)(long) ap_domain_index,
-					__match_queue_device_with_qid);
+					__match_queue_device_with_queue_id);
 		if (dev)
 			put_device(dev);
 		else
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index bfc66e4a9de1..d0059eae5d94 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -91,7 +91,8 @@ enum ap_state {
 	AP_STATE_WORKING,
 	AP_STATE_QUEUE_FULL,
 	AP_STATE_SUSPEND_WAIT,
-	AP_STATE_BORKED,
+	AP_STATE_UNBOUND,	/* momentary not bound to a driver */
+	AP_STATE_BORKED,	/* broken */
 	NR_AP_STATES
 };
 
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 576ac08777c5..ba261210c6da 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -420,6 +420,10 @@ static ap_func_t *ap_jumptable[NR_AP_STATES][NR_AP_EVENTS] = {
 		[AP_EVENT_POLL] = ap_sm_suspend_read,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
+	[AP_STATE_UNBOUND] = {
+		[AP_EVENT_POLL] = ap_sm_nop,
+		[AP_EVENT_TIMEOUT] = ap_sm_nop,
+	},
 	[AP_STATE_BORKED] = {
 		[AP_EVENT_POLL] = ap_sm_nop,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
@@ -725,6 +729,7 @@ static void __ap_flush_queue(struct ap_queue *aq)
 		ap_msg->rc = -EAGAIN;
 		ap_msg->receive(aq, ap_msg, NULL);
 	}
+	aq->queue_count = 0;
 }
 
 void ap_flush_queue(struct ap_queue *aq)
@@ -743,7 +748,7 @@ void ap_queue_remove(struct ap_queue *aq)
 	/* reset with zero, also clears irq registration */
 	spin_lock_bh(&aq->lock);
 	ap_zapq(aq->qid);
-	aq->state = AP_STATE_BORKED;
+	aq->state = AP_STATE_UNBOUND;
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_queue_remove);