Revert "leds: handle suspend/resume in heartbeat trigger"

This reverts commit 5ab92a7c.

System cannot enter suspend mode because of heartbeat led trigger.
In autosleep_wq, try_to_suspend function will try to enter suspend
mode in specific period. it will get wakeup_count then call pm_notifier
chain callback function and freeze processes.
Heartbeat_pm_notifier is called and it call led_trigger_unregister to
change the trigger of led device to none. It will send uevent message
and the wakeup source count changed. As wakeup_count changed, suspend
will abort.

Fixes: 5ab92a7c ("leds: handle suspend/resume in heartbeat trigger")
Signed-off-by: Zhang Bo <bo.zhang@nxp.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

drivers/leds/trigger/ledtrig-heartbeat.c

@@ -20,7 +20,6 @@
 #include <linux/sched/loadavg.h>
 #include <linux/leds.h>
 #include <linux/reboot.h>
-#include <linux/suspend.h>
 #include "../leds.h"
 
 static int panic_heartbeats;
@@ -163,30 +162,6 @@ static struct led_trigger heartbeat_led_trigger = {
 	.deactivate = heartbeat_trig_deactivate,
 };
 
-static int heartbeat_pm_notifier(struct notifier_block *nb,
-				 unsigned long pm_event, void *unused)
-{
-	int rc;
-
-	switch (pm_event) {
-	case PM_SUSPEND_PREPARE:
-	case PM_HIBERNATION_PREPARE:
-	case PM_RESTORE_PREPARE:
-		led_trigger_unregister(&heartbeat_led_trigger);
-		break;
-	case PM_POST_SUSPEND:
-	case PM_POST_HIBERNATION:
-	case PM_POST_RESTORE:
-		rc = led_trigger_register(&heartbeat_led_trigger);
-		if (rc)
-			pr_err("could not re-register heartbeat trigger\n");
-		break;
-	default:
-		break;
-	}
-	return NOTIFY_DONE;
-}
-
 static int heartbeat_reboot_notifier(struct notifier_block *nb,
 				     unsigned long code, void *unused)
 {
@@ -201,10 +176,6 @@ static int heartbeat_panic_notifier(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block heartbeat_pm_nb = {
-	.notifier_call = heartbeat_pm_notifier,
-};
-
 static struct notifier_block heartbeat_reboot_nb = {
 	.notifier_call = heartbeat_reboot_notifier,
 };
@@ -221,14 +192,12 @@ static int __init heartbeat_trig_init(void)
 		atomic_notifier_chain_register(&panic_notifier_list,
 					       &heartbeat_panic_nb);
 		register_reboot_notifier(&heartbeat_reboot_nb);
-		register_pm_notifier(&heartbeat_pm_nb);
 	}
 	return rc;
 }
 
 static void __exit heartbeat_trig_exit(void)
 {
-	unregister_pm_notifier(&heartbeat_pm_nb);
 	unregister_reboot_notifier(&heartbeat_reboot_nb);
 	atomic_notifier_chain_unregister(&panic_notifier_list,
 					 &heartbeat_panic_nb);