pmdomain/cpuidle: Add trace_prints about selected state for s2idle

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/pmdomain/governor.c

diff --git a/drivers/pmdomain/governor.c b/drivers/pmdomain/governor.c
index 96737ab..c36024c 100644
--- a/drivers/pmdomain/governor.c
+++ b/drivers/pmdomain/governor.c
@@ -443,11 +443,15 @@ static bool cpu_system_power_down_ok(struct dev_pm_domain *pd)
 
 		if (latency_ns <= constraint_ns) {
 			genpd->state_idx = state_idx;
+			trace_printk("Last CPU%d enters with state=%d\n",
+				     smp_processor_id(), state_idx);
 			return true;
 		}
 		state_idx--;
 	}
 
+	trace_printk("Last CPU%d failed to find a stated\n", smp_processor_id());
+
 	return false;
 }
 

kernel/sched/idle.c

diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index a83be0c..4ef2bdb 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -194,6 +194,10 @@ static void cpuidle_idle_call(bool stop_tick)
 	}
 
 	if (cpuidle_not_available(drv, dev)) {
+		if (idle_should_enter_s2idle())
+			trace_printk("s2idle: CPU%d enter with default idle call\n",
+				     smp_processor_id());
+
 		idle_call_stop_or_retain_tick(stop_tick);
 
 		default_idle_call();
@@ -217,17 +221,28 @@ static void cpuidle_idle_call(bool stop_tick)
 			max_latency_ns = cpu_wakeup_latency_qos_limit() *
 					 NSEC_PER_USEC;
 
+			trace_printk("s2idle-enter: max_latency_ns=%llu\n", max_latency_ns);
+
 			entered_state = call_cpuidle_s2idle(drv, dev,
 							    max_latency_ns);
+
+			trace_printk("s2idle-exit: state=%d\n", entered_state);
+
 			if (entered_state > 0)
 				goto exit_idle;
 		} else {
 			max_latency_ns = dev->forced_idle_latency_limit_ns;
 		}
 
+
+		trace_printk("s2idle-failed/forced: max_latency_ns=%llu\n", max_latency_ns);
+
 		tick_nohz_idle_stop_tick();
 
 		next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns);
+
+		trace_printk("s2idle-failed/forced: using state=%d\n", next_state);
+
 		call_cpuidle(drv, dev, next_state);
 	} else if (drv->state_count > 1) {
 		/*