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>

1 files changed, 27 insertions, 1 deletions

diff --git a/drivers/leds/ledtrig-heartbeat.c b/drivers/leds/ledtrig-heartbeat.c
index 1aacf4c6c3e4..41dc76db4311 100644
--- a/drivers/leds/ledtrig-heartbeat.c
+++ b/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);
 }