cpuidle: menu: Compute first_idx when latency_req is known

Since menu_select() can only set first_idx to 1 if the exit latency
of the second state is not greater than the latency limit, it should
first determine that limit.  Thus first_idx should be computed after
the "interactivity" factor has been taken into account.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewedy-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/cpuidle/governors/menu.c

@@ -322,22 +322,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	expected_interval = get_typical_interval(data);
 	expected_interval = min(expected_interval, data->next_timer_us);
 
-	first_idx = 0;
-	if (drv->states[0].flags & CPUIDLE_FLAG_POLLING) {
-		struct cpuidle_state *s = &drv->states[1];
-		unsigned int polling_threshold;
-
-		/*
-		 * Default to a physical idle state, not to busy polling, unless
-		 * a timer is going to trigger really really soon.
-		 */
-		polling_threshold = max_t(unsigned int, 20, s->target_residency);
-		if (data->next_timer_us > polling_threshold &&
-		    latency_req > s->exit_latency && !s->disabled &&
-		    !dev->states_usage[1].disable)
-			first_idx = 1;
-	}
-
 	/*
 	 * Use the lowest expected idle interval to pick the idle state.
 	 */
@@ -364,6 +348,22 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 			latency_req = interactivity_req;
 	}
 
+	first_idx = 0;
+	if (drv->states[0].flags & CPUIDLE_FLAG_POLLING) {
+		struct cpuidle_state *s = &drv->states[1];
+		unsigned int polling_threshold;
+
+		/*
+		 * Default to a physical idle state, not to busy polling, unless
+		 * a timer is going to trigger really really soon.
+		 */
+		polling_threshold = max_t(unsigned int, 20, s->target_residency);
+		if (data->next_timer_us > polling_threshold &&
+		    latency_req > s->exit_latency && !s->disabled &&
+		    !dev->states_usage[1].disable)
+			first_idx = 1;
+	}
+
 	/*
 	 * Find the idle state with the lowest power while satisfying
 	 * our constraints.