2 files changed, 31 insertions, 6 deletions

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 27f4332..ae21682 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -985,6 +985,23 @@ int irq_chip_set_affinity_parent(struct irq_data *data,
 }
 
 /**
+ * irq_chip_set_type_parent - Set IRQ type on the parent interrupt
+ * @data:	Pointer to interrupt specific data
+ * @type:	IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
+ *
+ * Conditional, as the underlying parent chip might not implement it.
+ */
+int irq_chip_set_type_parent(struct irq_data *data, unsigned int type)
+{
+	data = data->parent_data;
+
+	if (data->chip->irq_set_type)
+		return data->chip->irq_set_type(data, type);
+
+	return -ENOSYS;
+}
+
+/**
  * irq_chip_retrigger_hierarchy - Retrigger an interrupt in hardware
  * @data:	Pointer to interrupt specific data
  *
@@ -997,7 +1014,7 @@ int irq_chip_retrigger_hierarchy(struct irq_data *data)
 		if (data->chip && data->chip->irq_retrigger)
 			return data->chip->irq_retrigger(data);
 
-	return -ENOSYS;
+	return 0;
 }
 
 /**
diff --git a/kernel/irq/resend.c b/kernel/irq/resend.c
index 9065107..7a5237a 100644
--- a/kernel/irq/resend.c
+++ b/kernel/irq/resend.c
@@ -75,13 +75,21 @@ void check_irq_resend(struct irq_desc *desc, unsigned int irq)
 		    !desc->irq_data.chip->irq_retrigger(&desc->irq_data)) {
 #ifdef CONFIG_HARDIRQS_SW_RESEND
 			/*
-			 * If the interrupt has a parent irq and runs
-			 * in the thread context of the parent irq,
-			 * retrigger the parent.
+			 * If the interrupt is running in the thread
+			 * context of the parent irq we need to be
+			 * careful, because we cannot trigger it
+			 * directly.
 			 */
-			if (desc->parent_irq &&
-			    irq_settings_is_nested_thread(desc))
+			if (irq_settings_is_nested_thread(desc)) {
+				/*
+				 * If the parent_irq is valid, we
+				 * retrigger the parent, otherwise we
+				 * do nothing.
+				 */
+				if (!desc->parent_irq)
+					return;
 				irq = desc->parent_irq;
+			}
 			/* Set it pending and activate the softirq: */
 			set_bit(irq, irqs_resend);
 			tasklet_schedule(&resend_tasklet);