leds: heartbeat: stop on shutdown

A halted kernel should not show a heartbeat.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Cc: Shuah Khan <shuahkhan@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Bryan Wu <bryan.wu@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/leds/ledtrig-heartbeat.c

@@ -18,6 +18,7 @@
 #include <linux/timer.h>
 #include <linux/sched.h>
 #include <linux/leds.h>
+#include <linux/reboot.h>
 #include "leds.h"
 
 struct heartbeat_trig_data {
@@ -103,13 +104,38 @@ static struct led_trigger heartbeat_led_trigger = {
  .deactivate = heartbeat_trig_deactivate,
 };
 
+static int heartbeat_reboot_notifier(struct notifier_block *nb,
+ unsigned long code, void *unused)
+{
+ led_trigger_unregister(&heartbeat_led_trigger);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block heartbeat_reboot_nb = {
+ .notifier_call = heartbeat_reboot_notifier,
+};
+
+static struct notifier_block heartbeat_panic_nb = {
+ .notifier_call = heartbeat_reboot_notifier,
+};
+
 static int __init heartbeat_trig_init(void)
 {
- return led_trigger_register(&heartbeat_led_trigger);
+ int rc = led_trigger_register(&heartbeat_led_trigger);
+
+ if (!rc) {
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &heartbeat_panic_nb);
+ register_reboot_notifier(&heartbeat_reboot_nb);
+ }
+ return rc;
 }
 
 static void __exit heartbeat_trig_exit(void)
 {
+ unregister_reboot_notifier(&heartbeat_reboot_nb);
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &heartbeat_panic_nb);
  led_trigger_unregister(&heartbeat_led_trigger);
 }