diff --git a/include/linux/irq.h b/include/linux/irq.h
index f04ba20..60f8bc7 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -221,6 +221,17 @@
 extern int can_request_irq(unsigned int irq, unsigned long irqflags);
 
 extern void init_irq_proc(void);
+
+#ifdef CONFIG_AUTO_IRQ_AFFINITY
+extern int select_smp_affinity(unsigned int irq);
+#else
+static inline int
+select_smp_affinity(unsigned int irq)
+{
+	return 1;
+}
+#endif
+
 #endif
 
 extern hw_irq_controller no_irq_type;  /* needed in every arch ? */
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 81c49a4..97d5559 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -366,6 +366,8 @@
 	action->next = NULL;
 	action->dev_id = dev_id;
 
+	select_smp_affinity(irq);
+
 	retval = setup_irq(irq, action);
 	if (retval)
 		kfree(action);
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index f26e534..8a64a48 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -68,7 +68,9 @@
 	 */
 	cpus_and(tmp, new_value, cpu_online_map);
 	if (cpus_empty(tmp))
-		return -EINVAL;
+		/* Special case for empty set - allow the architecture
+		   code to set default SMP affinity. */
+		return select_smp_affinity(irq) ? -EINVAL : full_count;
 
 	proc_set_irq_affinity(irq, new_value);