core: callout: disable obsolete timeouts

In callout_service_cb() when a timeout interrupt is received there's a
check to see if this is the last scheduled CPU. If not the interrupt is
ignored, but not disabled causing it to trigger again and again. So fix
this by disabling the timeout too.

Fixes: cf707bd ("core: add callout service")
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>

core/kernel/callout.c

@@ -158,10 +158,13 @@ void callout_service_cb(void)
 		 * schedule_next_timeout() saves the core it was last
 		 * called on. If there's a mismatch here it means that
 		 * another core has been scheduled for the next callout, so
-		 * there's no work to be done for this core.
+		 * there's no work to be done for this core and we can
+		 * disable the timeout on this CPU.
 		 */
 		cpu_spin_lock(&callout_sched_lock);
 		do_callout = (get_core_pos() == callout_sched_core);
+		if (!do_callout)
+			desc->disable_timeout(desc);
 		cpu_spin_unlock(&callout_sched_lock);
 		if (!do_callout)
 			return;