1 files changed, 19 insertions, 3 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index a250d3a0af12..6f6644f819dd 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -206,6 +206,14 @@ struct irq_desc * __ref irq_to_desc_alloc_node(unsigned int irq, int node)
         return NULL;
 }
 
+static int irq_expand_nr_irqs(unsigned int cnt)
+{
+        if (nr_irqs + cnt > IRQ_BITMAP_BITS)
+                return -ENOMEM;
+        nr_irqs += cnt;
+        return 0;
+}
+
 int __init early_irq_init(void)
 {
         int i, initcnt, node = first_online_node;
@@ -287,6 +295,12 @@ static inline int alloc_descs(unsigned int start, unsigned int cnt, int node)
 {
         return start;
 }
+
+static int irq_expand_nr_irqs(unsigned int cnt)
+{
+        return -ENOMEM;
+}
+
 #endif /* !CONFIG_SPARSE_IRQ */
 
 /* Dynamic interrupt handling */
@@ -335,9 +349,11 @@ irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node)
         if (irq >=0 && start != irq)
                 goto err;
 
-        ret = -ENOMEM;
-        if (start >= nr_irqs)
-                goto err;
+        if (start >= nr_irqs) {
+                ret = irq_expand_nr_irqs(cnt);
+                if (ret)
+                        goto err;
+        }
 
         bitmap_set(allocated_irqs, start, cnt);
         mutex_unlock(&sparse_irq_lock);