2 files changed, 5 insertions, 1 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 81c49a4d679e..97d5559997d2 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -366,6 +366,8 @@ int request_irq(unsigned int irq,
         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 f26e534c6585..8a64a4844cde 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -68,7 +68,9 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
          */
         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);