drivers: nrf_rtc_timer: Remove unnecessary interrupt locking

There is no need to disable interrupts while just checking if
a channel needs to be processed in the ISR, as that section
does not contain anything that needs to be protected against
overwriting from some other context. In particular, if a given
timeout is changed or even aborted while its event is being
checked, this will be correctly handled in the code that follows
and that checks the expiration time.

Signed-off-by: Andrzej Głąbek <[email protected]>

Author: anangl

drivers/timer/nrf_rtc_timer.c

@@ -424,25 +424,18 @@ static void sys_clock_timeout_handler(int32_t chan,
 
 static bool channel_processing_check_and_clear(int32_t chan)
 {
-	bool result = false;
-
-	uint32_t mcu_critical_state = full_int_lock();
-
 	if (nrf_rtc_int_enable_check(RTC, RTC_CHANNEL_INT_MASK(chan))) {
 		/* The processing of channel can be caused by CC match
 		 * or be forced.
 		 */
-		result = (atomic_and(&force_isr_mask, ~BIT(chan)) & BIT(chan)) ||
-			 event_check(chan);
-
-		if (result) {
+		if ((atomic_and(&force_isr_mask, ~BIT(chan)) & BIT(chan)) ||
+		    event_check(chan)) {
 			event_clear(chan);
+			return true;
 		}
 	}
 
-	full_int_unlock(mcu_critical_state);
-
-	return result;
+	return false;
 }
 
 static void process_channel(int32_t chan)