diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 2758d05a802d..179ceb01e040 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -121,22 +121,13 @@ static struct bus_type ap_bus_type;
 /* Adapter interrupt definitions */
 static void ap_interrupt_handler(struct airq_struct *airq, bool floating);
 
-static int ap_airq_flag;
+static bool ap_irq_flag;
 
 static struct airq_struct ap_airq = {
 	.handler = ap_interrupt_handler,
 	.isc = AP_ISC,
 };
 
-/**
- * ap_using_interrupts() - Returns non-zero if interrupt support is
- * available.
- */
-static inline int ap_using_interrupts(void)
-{
-	return ap_airq_flag;
-}
-
 /**
  * ap_airq_ptr() - Get the address of the adapter interrupt indicator
  *
@@ -146,7 +137,7 @@ static inline int ap_using_interrupts(void)
  */
 void *ap_airq_ptr(void)
 {
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		return ap_airq.lsi_ptr;
 	return NULL;
 }
@@ -376,7 +367,7 @@ void ap_wait(enum ap_sm_wait wait)
 	switch (wait) {
 	case AP_SM_WAIT_AGAIN:
 	case AP_SM_WAIT_INTERRUPT:
-		if (ap_using_interrupts())
+		if (ap_irq_flag)
 			break;
 		if (ap_poll_kthread) {
 			wake_up(&ap_poll_wait);
@@ -451,7 +442,7 @@ static void ap_tasklet_fn(unsigned long dummy)
 	 * be received. Doing it in the beginning of the tasklet is therefor
 	 * important that no requests on any AP get lost.
 	 */
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		xchg(ap_airq.lsi_ptr, 0);
 
 	spin_lock_bh(&ap_queues_lock);
@@ -521,7 +512,7 @@ static int ap_poll_thread_start(void)
 {
 	int rc;
 
-	if (ap_using_interrupts() || ap_poll_kthread)
+	if (ap_irq_flag || ap_poll_kthread)
 		return 0;
 	mutex_lock(&ap_poll_thread_mutex);
 	ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
@@ -1119,7 +1110,7 @@ static BUS_ATTR_RO(ap_adapter_mask);
 static ssize_t ap_interrupts_show(struct bus_type *bus, char *buf)
 {
 	return scnprintf(buf, PAGE_SIZE, "%d\n",
-			 ap_using_interrupts() ? 1 : 0);
+			 ap_irq_flag ? 1 : 0);
 }
 
 static BUS_ATTR_RO(ap_interrupts);
@@ -1832,7 +1823,7 @@ static int __init ap_module_init(void)
 	/* enable interrupts if available */
 	if (ap_interrupts_available()) {
 		rc = register_adapter_interrupt(&ap_airq);
-		ap_airq_flag = (rc == 0);
+		ap_irq_flag = (rc == 0);
 	}
 
 	/* Create /sys/bus/ap. */
@@ -1876,7 +1867,7 @@ out_work:
 out_bus:
 	bus_unregister(&ap_bus_type);
 out:
-	if (ap_using_interrupts())
+	if (ap_irq_flag)
 		unregister_adapter_interrupt(&ap_airq);
 	kfree(ap_qci_info);
 	return rc;
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 472efd3a755c..2940bc8aa43d 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -77,12 +77,6 @@ static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
 #define AP_FUNC_EP11  5
 #define AP_FUNC_APXA  6
 
-/*
- * AP interrupt states
- */
-#define AP_INTR_DISABLED	0	/* AP interrupt disabled */
-#define AP_INTR_ENABLED		1	/* AP interrupt enabled */
-
 /*
  * AP queue state machine states
  */
@@ -109,7 +103,7 @@ enum ap_sm_event {
  * AP queue state wait behaviour
  */
 enum ap_sm_wait {
-	AP_SM_WAIT_AGAIN,	/* retry immediately */
+	AP_SM_WAIT_AGAIN = 0,	/* retry immediately */
 	AP_SM_WAIT_TIMEOUT,	/* wait for timeout */
 	AP_SM_WAIT_INTERRUPT,	/* wait for thin interrupt (if available) */
 	AP_SM_WAIT_NONE,	/* no wait */
@@ -182,7 +176,7 @@ struct ap_queue {
 	enum ap_dev_state dev_state;	/* queue device state */
 	bool config;			/* configured state */
 	ap_qid_t qid;			/* AP queue id. */
-	int interrupt;			/* indicate if interrupts are enabled */
+	bool interrupt;			/* indicate if interrupts are enabled */
 	int queue_count;		/* # messages currently on AP queue. */
 	int pendingq_count;		/* # requests on pendingq list. */
 	int requestq_count;		/* # requests on requestq list. */
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 337353c9655e..639f8d25679c 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -19,7 +19,7 @@
 static void __ap_flush_queue(struct ap_queue *aq);
 
 /**
- * ap_queue_enable_interruption(): Enable interruption on an AP queue.
+ * ap_queue_enable_irq(): Enable interrupt support on this AP queue.
  * @qid: The AP queue number
  * @ind: the notification indicator byte
  *
@@ -27,7 +27,7 @@ static void __ap_flush_queue(struct ap_queue *aq);
  * value it waits a while and tests the AP queue if interrupts
  * have been switched on using ap_test_queue().
  */
-static int ap_queue_enable_interruption(struct ap_queue *aq, void *ind)
+static int ap_queue_enable_irq(struct ap_queue *aq, void *ind)
 {
 	struct ap_queue_status status;
 	struct ap_qirq_ctrl qirqctrl = { 0 };
@@ -198,7 +198,8 @@ static enum ap_sm_wait ap_sm_read(struct ap_queue *aq)
 		return AP_SM_WAIT_NONE;
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		if (aq->queue_count > 0)
-			return AP_SM_WAIT_INTERRUPT;
+			return aq->interrupt ?
+				AP_SM_WAIT_INTERRUPT : AP_SM_WAIT_TIMEOUT;
 		aq->sm_state = AP_SM_STATE_IDLE;
 		return AP_SM_WAIT_NONE;
 	default:
@@ -252,7 +253,8 @@ static enum ap_sm_wait ap_sm_write(struct ap_queue *aq)
 		fallthrough;
 	case AP_RESPONSE_Q_FULL:
 		aq->sm_state = AP_SM_STATE_QUEUE_FULL;
-		return AP_SM_WAIT_INTERRUPT;
+		return aq->interrupt ?
+			AP_SM_WAIT_INTERRUPT : AP_SM_WAIT_TIMEOUT;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->sm_state = AP_SM_STATE_RESET_WAIT;
 		return AP_SM_WAIT_TIMEOUT;
@@ -302,7 +304,7 @@ static enum ap_sm_wait ap_sm_reset(struct ap_queue *aq)
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->sm_state = AP_SM_STATE_RESET_WAIT;
-		aq->interrupt = AP_INTR_DISABLED;
+		aq->interrupt = false;
 		return AP_SM_WAIT_TIMEOUT;
 	default:
 		aq->dev_state = AP_DEV_STATE_ERROR;
@@ -335,7 +337,7 @@ static enum ap_sm_wait ap_sm_reset_wait(struct ap_queue *aq)
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		lsi_ptr = ap_airq_ptr();
-		if (lsi_ptr && ap_queue_enable_interruption(aq, lsi_ptr) == 0)
+		if (lsi_ptr && ap_queue_enable_irq(aq, lsi_ptr) == 0)
 			aq->sm_state = AP_SM_STATE_SETIRQ_WAIT;
 		else
 			aq->sm_state = (aq->queue_count > 0) ?
@@ -376,7 +378,7 @@ static enum ap_sm_wait ap_sm_setirq_wait(struct ap_queue *aq)
 
 	if (status.irq_enabled == 1) {
 		/* Irqs are now enabled */
-		aq->interrupt = AP_INTR_ENABLED;
+		aq->interrupt = true;
 		aq->sm_state = (aq->queue_count > 0) ?
 			AP_SM_STATE_WORKING : AP_SM_STATE_IDLE;
 	}
@@ -566,7 +568,7 @@ static ssize_t interrupt_show(struct device *dev,
 	spin_lock_bh(&aq->lock);
 	if (aq->sm_state == AP_SM_STATE_SETIRQ_WAIT)
 		rc = scnprintf(buf, PAGE_SIZE, "Enable Interrupt pending.\n");
-	else if (aq->interrupt == AP_INTR_ENABLED)
+	else if (aq->interrupt)
 		rc = scnprintf(buf, PAGE_SIZE, "Interrupts enabled.\n");
 	else
 		rc = scnprintf(buf, PAGE_SIZE, "Interrupts disabled.\n");
@@ -747,7 +749,7 @@ struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type)
 	aq->ap_dev.device.type = &ap_queue_type;
 	aq->ap_dev.device_type = device_type;
 	aq->qid = qid;
-	aq->interrupt = AP_INTR_DISABLED;
+	aq->interrupt = false;
 	spin_lock_init(&aq->lock);
 	INIT_LIST_HEAD(&aq->pendingq);
 	INIT_LIST_HEAD(&aq->requestq);
