diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index fa5de5e..451f9d0 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Alarmtimer interface
  *
@@ -10,10 +11,6 @@
  * Copyright (C) 2010 IBM Corperation
  *
  * Author: John Stultz <john.stultz@linaro.org>
- *
- * 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/time.h>
 #include <linux/hrtimer.h>
@@ -100,7 +97,7 @@
 	if (!device_may_wakeup(rtc->dev.parent))
 		return -1;
 
-	__ws = wakeup_source_register("alarmtimer");
+	__ws = wakeup_source_register(dev, "alarmtimer");
 
 	spin_lock_irqsave(&rtcdev_lock, flags);
 	if (!rtcdev) {
@@ -236,7 +233,6 @@
 /**
  * alarmtimer_suspend - Suspend time callback
  * @dev: unused
- * @state: unused
  *
  * When we are going into suspend, we look through the bases
  * to see which is the soonest timer to expire. We then
@@ -436,7 +432,7 @@
 		int ret = alarm_try_to_cancel(alarm);
 		if (ret >= 0)
 			return ret;
-		cpu_relax();
+		hrtimer_cancel_wait_running(&alarm->timer);
 	}
 }
 EXPORT_SYMBOL_GPL(alarm_cancel);
@@ -597,7 +593,7 @@
 {
 	struct alarm *alarm = &timr->it.alarm.alarmtimer;
 
-	return ktime_sub(now, alarm->node.expires);
+	return ktime_sub(alarm->node.expires, now);
 }
 
 /**
@@ -610,6 +606,19 @@
 }
 
 /**
+ * alarm_timer_wait_running - Posix timer callback to wait for a timer
+ * @timr:	Pointer to the posixtimer data struct
+ *
+ * Called from the core code when timer cancel detected that the callback
+ * is running. @timr is unlocked and rcu read lock is held to prevent it
+ * from being freed.
+ */
+static void alarm_timer_wait_running(struct k_itimer *timr)
+{
+	hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer);
+}
+
+/**
  * alarm_timer_arm - Posix timer callback to arm a timer
  * @timr:	Pointer to the posixtimer data struct
  * @expires:	The new expiry time
@@ -676,7 +685,7 @@
 	enum  alarmtimer_type type;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (!capable(CAP_WAKE_ALARM))
 		return -EPERM;
@@ -794,7 +803,7 @@
 	int ret = 0;
 
 	if (!alarmtimer_get_rtcdev())
-		return -ENOTSUPP;
+		return -EOPNOTSUPP;
 
 	if (flags & ~TIMER_ABSTIME)
 		return -EINVAL;
@@ -838,6 +847,7 @@
 	.timer_forward		= alarm_timer_forward,
 	.timer_remaining	= alarm_timer_remaining,
 	.timer_try_to_cancel	= alarm_timer_try_to_cancel,
+	.timer_wait_running	= alarm_timer_wait_running,
 	.nsleep			= alarm_timer_nsleep,
 };
 #endif /* CONFIG_POSIX_TIMERS */