PM / s2idle: Rearrange the main suspend-to-idle loop

As a preparation for subsequent changes, rearrange the core
suspend-to-idle code by moving the initial invocation of
dpm_suspend_noirq() into s2idle_loop().

This also causes debug messages from that code to appear in
a less confusing order.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/power/power.h

@@ -245,7 +245,11 @@ enum {
 #define TEST_FIRST	TEST_NONE
 #define TEST_MAX	(__TEST_AFTER_LAST - 1)
 
+#ifdef CONFIG_PM_DEBUG
 extern int pm_test_level;
+#else
+#define pm_test_level	(TEST_NONE)
+#endif
 
 #ifdef CONFIG_SUSPEND_FREEZER
 static inline int suspend_freeze_processes(void)

kernel/power/suspend.c

@@ -108,7 +108,13 @@ static void s2idle_loop(void)
 {
 	pm_pr_dbg("suspend-to-idle\n");
 
-	do {
+	while (!dpm_suspend_noirq(PMSG_SUSPEND)) {
+		/*
+		 * Suspend-to-idle equals
+		 * frozen processes + suspended devices + idle processors.
+		 * Thus freeze_enter() should be called right after
+		 * all devices have been suspended.
+		 */
 		freeze_enter();
 
 		if (freeze_ops && freeze_ops->wake)
@@ -122,7 +128,7 @@ static void s2idle_loop(void)
 			break;
 
 		pm_wakeup_clear(false);
-	} while (!dpm_suspend_noirq(PMSG_SUSPEND));
+	}
 
 	pm_pr_dbg("resume from suspend-to-idle\n");
 }
@@ -379,6 +385,11 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (error)
 		goto Devices_early_resume;
 
+	if (state == PM_SUSPEND_FREEZE && pm_test_level != TEST_PLATFORM) {
+		s2idle_loop();
+		goto Platform_early_resume;
+	}
+
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
 		pr_err("PM: noirq suspend of devices failed\n");
@@ -391,17 +402,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	if (suspend_test(TEST_PLATFORM))
 		goto Platform_wake;
 
-	/*
-	 * PM_SUSPEND_FREEZE equals
-	 * frozen processes + suspended devices + idle processors.
-	 * Thus we should invoke freeze_enter() soon after
-	 * all the devices are suspended.
-	 */
-	if (state == PM_SUSPEND_FREEZE) {
-		s2idle_loop();
-		goto Platform_early_resume;
-	}
-
 	error = disable_nonboot_cpus();
 	if (error || suspend_test(TEST_CPUS))
 		goto Enable_cpus;