ba93cdce5b
This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which allows to mark a specific LED to be switched to the "panic" trigger, on a kernel panic. This is useful to allow the user to assign a regular trigger to a given LED, and still blink that LED on a kernel panic. Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Reviewed-by: Matthias Brugger <mbrugger@suse.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
78 lines
1.9 KiB
C
78 lines
1.9 KiB
C
/*
|
|
* 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);
|