mpsl: init: Stop triggering sched and PM from ZLI ISRs

Zero latensy interrupt handlers are not allowed to use kernel APIs.
Zephyr documentation states that use of kernel APIs must be considered
as undefined behavior. The same goes for triggering kernel scheduler
by `return 1;` at end of an ISR and use of PM subsystem related macros
like ISR_DIRECT_PM.

Signed-off-by: Piotr Pryga <[email protected]>

Author: ppryga-nordic

subsys/mpsl/init/mpsl_init.c

@@ -222,8 +222,6 @@ static void mpsl_timer0_isr_wrapper(const void *args)
 	ARG_UNUSED(args);
 
 	MPSL_IRQ_TIMER0_Handler();
-
-	ISR_DIRECT_PM();
 }
 
 static void mpsl_rtc0_isr_wrapper(const void *args)
@@ -236,17 +234,13 @@ static void mpsl_rtc0_isr_wrapper(const void *args)
 	}
 
 	MPSL_IRQ_RTC0_Handler();
-
-	ISR_DIRECT_PM();
 }
 
 static void mpsl_radio_isr_wrapper(const void *args)
 {
 	ARG_UNUSED(args);
 
 	MPSL_IRQ_RADIO_Handler();
-
-	ISR_DIRECT_PM();
 }
 
 static void mpsl_lib_irq_disable(void)
@@ -277,12 +271,7 @@ ISR_DIRECT_DECLARE(mpsl_timer0_isr_wrapper)
 {
 	MPSL_IRQ_TIMER0_Handler();
 
-	ISR_DIRECT_PM();
-
-	/* We may need to reschedule in case a radio timeslot callback
-	 * accesses zephyr primitives.
-	 */
-	return 1;
+	return 0;
 }
 
 ISR_DIRECT_DECLARE(mpsl_rtc0_isr_wrapper)
@@ -293,24 +282,14 @@ ISR_DIRECT_DECLARE(mpsl_rtc0_isr_wrapper)
 	}
 	MPSL_IRQ_RTC0_Handler();
 
-	ISR_DIRECT_PM();
-
-	/* No need for rescheduling, because the interrupt handler
-	 * does not access zephyr primitives.
-	 */
 	return 0;
 }
 
 ISR_DIRECT_DECLARE(mpsl_radio_isr_wrapper)
 {
 	MPSL_IRQ_RADIO_Handler();
 
-	ISR_DIRECT_PM();
-
-	/* We may need to reschedule in case a radio timeslot callback
-	 * accesses zephyr primitives.
-	 */
-	return 1;
+	return 0;
 }
 #endif /* IS_ENABLED(CONFIG_MPSL_DYNAMIC_INTERRUPTS) */
 
@@ -492,18 +471,12 @@ static int mpsl_lib_init_sys(void)
 	/* Ensure IRQs are disabled before attaching. */
 	mpsl_lib_irq_disable();
 
-	/* We may need to reschedule in case a radio timeslot callback
-	 * accesses Zephyr primitives.
-	 * The RTC0 interrupt handler does not access zephyr primitives,
-	 * however, as this decision needs to be made during build-time,
-	 * rescheduling is performed to account for user-provided handlers.
-	 */
 	ARM_IRQ_DIRECT_DYNAMIC_CONNECT(MPSL_TIMER_IRQn, MPSL_HIGH_IRQ_PRIORITY, IRQ_CONNECT_FLAGS,
-				       reschedule);
+				       no_reschedule);
 	ARM_IRQ_DIRECT_DYNAMIC_CONNECT(MPSL_RTC_IRQn, MPSL_HIGH_IRQ_PRIORITY, IRQ_CONNECT_FLAGS,
-				       reschedule);
+				       no_reschedule);
 	ARM_IRQ_DIRECT_DYNAMIC_CONNECT(MPSL_RADIO_IRQn, MPSL_HIGH_IRQ_PRIORITY, IRQ_CONNECT_FLAGS,
-				       reschedule);
+				       no_reschedule);
 
 	mpsl_lib_irq_connect();
 #else /* !IS_ENABLED(CONFIG_MPSL_DYNAMIC_INTERRUPTS) */