PM: suspend: Do not pause cpuidle in the suspend-to-idle path

It is pointless to pause cpuidle in the suspend-to-idle path,
because it is going to be resumed in the same path later and
pausing it does not serve any particular purpose in that case.

Rework the code to avoid doing that.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Tested-by: Ulf Hansson <[email protected]>

Author: rafaeljw

drivers/base/power/main.c

@@ -747,8 +747,6 @@ void dpm_resume_noirq(pm_message_t state)
 
 	resume_device_irqs();
 	device_wakeup_disarm_wake_irqs();
-
-	cpuidle_resume();
 }
 
 /**
@@ -881,6 +879,7 @@ void dpm_resume_early(pm_message_t state)
 void dpm_resume_start(pm_message_t state)
 {
 	dpm_resume_noirq(state);
+	cpuidle_resume();
 	dpm_resume_early(state);
 }
 EXPORT_SYMBOL_GPL(dpm_resume_start);
@@ -1337,8 +1336,6 @@ int dpm_suspend_noirq(pm_message_t state)
 {
 	int ret;
 
-	cpuidle_pause();
-
 	device_wakeup_arm_wake_irqs();
 	suspend_device_irqs();
 
@@ -1522,9 +1519,13 @@ int dpm_suspend_end(pm_message_t state)
 	if (error)
 		goto out;
 
+	cpuidle_pause();
+
 	error = dpm_suspend_noirq(state);
-	if (error)
+	if (error) {
+		cpuidle_resume();
 		dpm_resume_early(resume_event(state));
+	}
 
 out:
 	dpm_show_time(starttime, state, error, "end");

kernel/power/suspend.c

@@ -97,15 +97,13 @@ static void s2idle_enter(void)
 	raw_spin_unlock_irq(&s2idle_lock);
 
 	cpus_read_lock();
-	cpuidle_resume();
 
 	/* Push all the CPUs into the idle loop. */
 	wake_up_all_idle_cpus();
 	/* Make the current CPU wait so it can enter the idle loop too. */
 	swait_event_exclusive(s2idle_wait_head,
 		    s2idle_state == S2IDLE_STATE_WAKE);
 
-	cpuidle_pause();
 	cpus_read_unlock();
 
 	raw_spin_lock_irq(&s2idle_lock);
@@ -405,6 +403,9 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (error)
 		goto Devices_early_resume;
 
+	if (state != PM_SUSPEND_TO_IDLE)
+		cpuidle_pause();
+
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
 		pr_err("noirq suspend of devices failed\n");
@@ -459,6 +460,9 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	dpm_resume_noirq(PMSG_RESUME);
 
  Platform_early_resume:
+	if (state != PM_SUSPEND_TO_IDLE)
+		cpuidle_resume();
+
 	platform_resume_early(state);
 
  Devices_early_resume: