diff --git a/[refs] b/[refs]
index ede617676824..21eeeb9bf356 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6ac8579b96e3bc3581c3a42b326647594e5bbb03
+refs/heads/master: 29473822943ab5357cf3fcb718483f07f3188b83
diff --git a/trunk/arch/mips/ralink/irq.c b/trunk/arch/mips/ralink/irq.c
index d9807d0587cd..320b1f1043ff 100644
--- a/trunk/arch/mips/ralink/irq.c
+++ b/trunk/arch/mips/ralink/irq.c
@@ -166,6 +166,7 @@ static int __init intc_of_init(struct device_node *node,
 	irq_set_chained_handler(irq, ralink_intc_irq_handler);
 	irq_set_handler_data(irq, domain);
 
+	/* tell the kernel which irq is used for performance monitoring */
 	cp0_perfcount_irq = irq_create_mapping(domain, 9);
 
 	return 0;