diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c
index b3a5549..0cbff18 100644
--- a/kernel/irq/autoprobe.c
+++ b/kernel/irq/autoprobe.c
@@ -30,19 +30,16 @@
 unsigned long probe_irq_on(void)
 {
 	struct irq_desc *desc;
-	unsigned long mask;
-	unsigned int i;
+	unsigned long mask = 0;
+	unsigned int status;
+	int i;
 
 	mutex_lock(&probing_active);
 	/*
 	 * something may have generated an irq long ago and we want to
 	 * flush such a longstanding irq before considering it as spurious.
 	 */
-	for (i = nr_irqs-1; i > 0; i--) {
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
-
+	for_each_irq_desc_reverse(i, desc) {
 		spin_lock_irq(&desc->lock);
 		if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
 			/*
@@ -70,11 +67,7 @@
 	 * (we must startup again here because if a longstanding irq
 	 * happened in the previous stage, it may have masked itself)
 	 */
-	for (i = nr_irqs-1; i > 0; i--) {
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
-
+	for_each_irq_desc_reverse(i, desc) {
 		spin_lock_irq(&desc->lock);
 		if (!desc->action && !(desc->status & IRQ_NOPROBE)) {
 			desc->status |= IRQ_AUTODETECT | IRQ_WAITING;
@@ -92,13 +85,7 @@
 	/*
 	 * Now filter out any obviously spurious interrupts
 	 */
-	mask = 0;
-	for (i = 0; i < nr_irqs; i++) {
-		unsigned int status;
-
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
+	for_each_irq_desc(i, desc) {
 		spin_lock_irq(&desc->lock);
 		status = desc->status;
 
@@ -132,16 +119,11 @@
  */
 unsigned int probe_irq_mask(unsigned long val)
 {
-	unsigned int mask;
+	unsigned int status, mask = 0;
+	struct irq_desc *desc;
 	int i;
 
-	mask = 0;
-	for (i = 0; i < nr_irqs; i++) {
-		struct irq_desc *desc = irq_to_desc(i);
-		unsigned int status;
-
-		if (!desc)
-			continue;
+	for_each_irq_desc(i, desc) {
 		spin_lock_irq(&desc->lock);
 		status = desc->status;
 
@@ -180,13 +162,10 @@
 int probe_irq_off(unsigned long val)
 {
 	int i, irq_found = 0, nr_irqs = 0;
+	struct irq_desc *desc;
+	unsigned int status;
 
-	for (i = 0; i < nr_irqs; i++) {
-		struct irq_desc *desc = irq_to_desc(i);
-		unsigned int status;
-
-		if (!desc)
-			continue;
+	for_each_irq_desc(i, desc) {
 		spin_lock_irq(&desc->lock);
 		status = desc->status;