PM: sleep: Integrate suspend-to-idle with generig suspend flow

After previous changes the suspend-to-idle code flow can be
integrated more tightly with the generic system suspend code flow
by making suspend_enter() call s2idle_loop() later and removing
the direct invocations of dpm_noirq_begin(),
dpm_noirq_suspend_devices(), dpm_noirq_end(), and
dpm_noirq_resume_devices() from the latter, so do that.

This change is not expected to alter functionality.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

kernel/power/suspend.c

@@ -119,13 +119,6 @@ static void s2idle_enter(void)
 
 static void s2idle_loop(void)
 {
-	int error;
-
-	dpm_noirq_begin();
-	error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
-	if (error)
-		goto resume;
-
 	pm_pr_dbg("suspend-to-idle\n");
 
 	/*
@@ -150,10 +143,6 @@ static void s2idle_loop(void)
 	}
 
 	pm_pr_dbg("resume from suspend-to-idle\n");
-
-resume:
-	dpm_noirq_resume_devices(PMSG_RESUME);
-	dpm_noirq_end();
 }
 
 void s2idle_wake(void)
@@ -408,11 +397,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (error)
 		goto Devices_early_resume;
 
-	if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
-		s2idle_loop();
-		goto Platform_early_resume;
-	}
-
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
 		pr_err("noirq suspend of devices failed\n");
@@ -425,6 +409,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (suspend_test(TEST_PLATFORM))
 		goto Platform_wake;
 
+	if (state == PM_SUSPEND_TO_IDLE) {
+		s2idle_loop();
+		goto Platform_wake;
+	}
+
 	error = suspend_disable_secondary_cpus();
 	if (error || suspend_test(TEST_CPUS))
 		goto Enable_cpus;