ARM: Move leds idle start/stop calls to idle notifiers

Change-Id: I5d8e4e85b17bbab7992ecb477f0bdb5e4138b166
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>

arch/arm/kernel/leds.c

@@ -9,6 +9,8 @@
  */
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
 #include <linux/sysdev.h>
 
 #include <asm/leds.h>
@@ -99,6 +101,25 @@ static struct sys_device leds_device = {
 	.cls		= &leds_sysclass,
 };
 
+static int leds_idle_notifier(struct notifier_block *nb, unsigned long val,
+                                void *data)
+{
+	switch (val) {
+	case IDLE_START:
+		leds_event(led_idle_start);
+		break;
+	case IDLE_END:
+		leds_event(led_idle_end);
+		break;
+	}
+
+	return 0;
+}
+
+static struct notifier_block leds_idle_nb = {
+	.notifier_call = leds_idle_notifier,
+};
+
 static int __init leds_init(void)
 {
 	int ret;
@@ -107,6 +128,9 @@ static int __init leds_init(void)
 		ret = sysdev_register(&leds_device);
 	if (ret == 0)
 		ret = sysdev_create_file(&leds_device, &attr_event);
+	if (ret == 0)
+		idle_notifier_register(&leds_idle_nb);
+
 	return ret;
 }
 

arch/arm/kernel/process.c

@@ -29,7 +29,6 @@
 #include <linux/utsname.h>
 #include <linux/uaccess.h>
 
-#include <asm/leds.h>
 #include <asm/processor.h>
 #include <asm/system.h>
 #include <asm/thread_notify.h>
@@ -147,7 +146,6 @@ void cpu_idle(void)
 	/* endless idle loop with no priority at all */
 	while (1) {
 		tick_nohz_stop_sched_tick(1);
-		leds_event(led_idle_start);
 		idle_notifier_call_chain(IDLE_START);
 		while (!need_resched()) {
 #ifdef CONFIG_HOTPLUG_CPU
@@ -172,7 +170,6 @@ void cpu_idle(void)
 				local_irq_enable();
 			}
 		}
-		leds_event(led_idle_end);
 		idle_notifier_call_chain(IDLE_END);
 		tick_nohz_restart_sched_tick();
 		preempt_enable_no_resched();