diff --git a/[refs] b/[refs]
index 12c4ad84f230..87f8c67cea9b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8b8f319fc7f4ab59f567d6a401a62659b3d37007
+refs/heads/master: 243c7621aac4ed1aa79524c9a1cecf7c05a28124
diff --git a/trunk/include/linux/lockdep.h b/trunk/include/linux/lockdep.h
index 80ec7a4dbc98..316e0fb8d7b1 100644
--- a/trunk/include/linux/lockdep.h
+++ b/trunk/include/linux/lockdep.h
@@ -270,6 +270,12 @@ static inline int lockdep_internal(void)
 struct lock_class_key { };
 #endif /* !LOCKDEP */
 
+#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
+extern void early_init_irq_lock_class(void);
+#else
+# define early_init_irq_lock_class()		do { } while (0)
+#endif
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 extern void early_boot_irqs_off(void);
 extern void early_boot_irqs_on(void);
diff --git a/trunk/init/main.c b/trunk/init/main.c
index fc473d4b56fd..628b8e9e841a 100644
--- a/trunk/init/main.c
+++ b/trunk/init/main.c
@@ -466,6 +466,7 @@ asmlinkage void __init start_kernel(void)
 
 	local_irq_disable();
 	early_boot_irqs_off();
+	early_init_irq_lock_class();
 
 /*
  * Interrupts are still disabled. Do necessary setups, then
diff --git a/trunk/kernel/irq/handle.c b/trunk/kernel/irq/handle.c
index aeb6e391276c..a7b497ee919e 100644
--- a/trunk/kernel/irq/handle.c
+++ b/trunk/kernel/irq/handle.c
@@ -249,3 +249,19 @@ fastcall unsigned int __do_IRQ(unsigned int irq, struct pt_regs *regs)
 	return 1;
 }
 
+#ifdef CONFIG_TRACE_IRQFLAGS
+
+/*
+ * lockdep: we want to handle all irq_desc locks as a single lock-class:
+ */
+static struct lock_class_key irq_desc_lock_class;
+
+void early_init_irq_lock_class(void)
+{
+	int i;
+
+	for (i = 0; i < NR_IRQS; i++)
+		lockdep_set_class(&irq_desc[i].lock, &irq_desc_lock_class);
+}
+
+#endif