1 files changed, 29 insertions, 10 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index c03f71d5ec10..e3e245a4fd70 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1249,6 +1249,31 @@ static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action)
 }
 
 /*
+ * Internal function to notify that a interrupt thread is ready.
+ */
+static void irq_thread_set_ready(struct irq_desc *desc,
+				 struct irqaction *action)
+{
+	set_bit(IRQTF_READY, &action->thread_flags);
+	wake_up(&desc->wait_for_threads);
+}
+
+/*
+ * Internal function to wake up a interrupt thread and wait until it is
+ * ready.
+ */
+static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc,
+						  struct irqaction *action)
+{
+	if (!action || !action->thread)
+		return;
+
+	wake_up_process(action->thread);
+	wait_event(desc->wait_for_threads,
+		   test_bit(IRQTF_READY, &action->thread_flags));
+}
+
+/*
  * Interrupt handler thread
  */
 static int irq_thread(void *data)
@@ -1259,6 +1284,8 @@ static int irq_thread(void *data)
 	irqreturn_t (*handler_fn)(struct irq_desc *desc,
 			struct irqaction *action);
 
+	irq_thread_set_ready(desc, action);
+
 	sched_set_fifo(current);
 
 	if (force_irqthreads() && test_bit(IRQTF_FORCED_THREAD,
@@ -1683,8 +1710,6 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 	}
 
 	if (!shared) {
-		init_waitqueue_head(&desc->wait_for_threads);
-
 		/* Setup the type (level, edge polarity) if configured: */
 		if (new->flags & IRQF_TRIGGER_MASK) {
 			ret = __irq_set_trigger(desc,
@@ -1780,14 +1805,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
 	irq_setup_timings(desc, new);
 
-	/*
-	 * Strictly no need to wake it up, but hung_task complains
-	 * when no hard interrupt wakes the thread up.
-	 */
-	if (new->thread)
-		wake_up_process(new->thread);
-	if (new->secondary)
-		wake_up_process(new->secondary->thread);
+	wake_up_and_wait_for_irq_thread_ready(desc, new);
+	wake_up_and_wait_for_irq_thread_ready(desc, new->secondary);
 
 	register_irq_proc(irq, desc);
 	new->dir = NULL;