v4.19.13 snapshot.
diff --git a/drivers/leds/trigger/ledtrig-panic.c b/drivers/leds/trigger/ledtrig-panic.c
new file mode 100644
index 0000000..d735526
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-panic.c
@@ -0,0 +1,77 @@
+/*
+ * Kernel Panic LED Trigger
+ *
+ * Copyright 2016 Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/notifier.h>
+#include <linux/leds.h>
+#include "../leds.h"
+
+static struct led_trigger *trigger;
+
+/*
+ * This is called in a special context by the atomic panic
+ * notifier. This means the trigger can be changed without
+ * worrying about locking.
+ */
+static void led_trigger_set_panic(struct led_classdev *led_cdev)
+{
+ struct led_trigger *trig;
+
+ list_for_each_entry(trig, &trigger_list, next_trig) {
+ if (strcmp("panic", trig->name))
+ continue;
+ if (led_cdev->trigger)
+ list_del(&led_cdev->trig_list);
+ list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
+
+ /* Avoid the delayed blink path */
+ led_cdev->blink_delay_on = 0;
+ led_cdev->blink_delay_off = 0;
+
+ led_cdev->trigger = trig;
+ if (trig->activate)
+ trig->activate(led_cdev);
+ break;
+ }
+}
+
+static int led_trigger_panic_notifier(struct notifier_block *nb,
+ unsigned long code, void *unused)
+{
+ struct led_classdev *led_cdev;
+
+ list_for_each_entry(led_cdev, &leds_list, node)
+ if (led_cdev->flags & LED_PANIC_INDICATOR)
+ led_trigger_set_panic(led_cdev);
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block led_trigger_panic_nb = {
+ .notifier_call = led_trigger_panic_notifier,
+};
+
+static long led_panic_blink(int state)
+{
+ led_trigger_event(trigger, state ? LED_FULL : LED_OFF);
+ return 0;
+}
+
+static int __init ledtrig_panic_init(void)
+{
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &led_trigger_panic_nb);
+
+ led_trigger_register_simple("panic", &trigger);
+ panic_blink = led_panic_blink;
+ return 0;
+}
+device_initcall(ledtrig_panic_init);