PM: sleep: Move some assignments from under a lock

The async_error and pm_transition variables are set under dpm_list_mtx
in multiple places in the system-wide device PM core code, which is
unnecessary and confusing, so rearrange the code so that the variables
in question are set before acquiring the lock.

While at it, add some empty code lines around locking to improve the
consistency of the code.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Author: rafaeljw

drivers/base/power/main.c

@@ -707,9 +707,9 @@ static void dpm_noirq_resume_devices(pm_message_t state)
 	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 
 	async_error = 0;
+	pm_transition = state;
 
 	mutex_lock(&dpm_list_mtx);
-	pm_transition = state;
 
 	/*
 	 * Trigger the resume of "async" devices upfront so they don't have to
@@ -847,9 +847,9 @@ void dpm_resume_early(pm_message_t state)
 	trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 
 	async_error = 0;
+	pm_transition = state;
 
 	mutex_lock(&dpm_list_mtx);
-	pm_transition = state;
 
 	/*
 	 * Trigger the resume of "async" devices upfront so they don't have to
@@ -1012,10 +1012,11 @@ void dpm_resume(pm_message_t state)
 	trace_suspend_resume(TPS("dpm_resume"), state.event, true);
 	might_sleep();
 
-	mutex_lock(&dpm_list_mtx);
 	pm_transition = state;
 	async_error = 0;
 
+	mutex_lock(&dpm_list_mtx);
+
 	/*
 	 * Trigger the resume of "async" devices upfront so they don't have to
 	 * wait for the "non-async" ones they don't depend on.
@@ -1294,10 +1295,12 @@ static int dpm_noirq_suspend_devices(pm_message_t state)
 	int error = 0;
 
 	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
-	mutex_lock(&dpm_list_mtx);
+
 	pm_transition = state;
 	async_error = 0;
 
+	mutex_lock(&dpm_list_mtx);
+
 	while (!list_empty(&dpm_late_early_list)) {
 		struct device *dev = to_device(dpm_late_early_list.prev);
 
@@ -1320,7 +1323,9 @@ static int dpm_noirq_suspend_devices(pm_message_t state)
 		if (error || async_error)
 			break;
 	}
+
 	mutex_unlock(&dpm_list_mtx);
+
 	async_synchronize_full();
 	if (!error)
 		error = async_error;
@@ -1470,11 +1475,14 @@ int dpm_suspend_late(pm_message_t state)
 	int error = 0;
 
 	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
-	wake_up_all_idle_cpus();
-	mutex_lock(&dpm_list_mtx);
+
 	pm_transition = state;
 	async_error = 0;
 
+	wake_up_all_idle_cpus();
+
+	mutex_lock(&dpm_list_mtx);
+
 	while (!list_empty(&dpm_suspended_list)) {
 		struct device *dev = to_device(dpm_suspended_list.prev);
 
@@ -1498,7 +1506,9 @@ int dpm_suspend_late(pm_message_t state)
 		if (error || async_error)
 			break;
 	}
+
 	mutex_unlock(&dpm_list_mtx);
+
 	async_synchronize_full();
 	if (!error)
 		error = async_error;
@@ -1745,9 +1755,11 @@ int dpm_suspend(pm_message_t state)
 	devfreq_suspend();
 	cpufreq_suspend();
 
-	mutex_lock(&dpm_list_mtx);
 	pm_transition = state;
 	async_error = 0;
+
+	mutex_lock(&dpm_list_mtx);
+
 	while (!list_empty(&dpm_prepared_list)) {
 		struct device *dev = to_device(dpm_prepared_list.prev);
 
@@ -1771,7 +1783,9 @@ int dpm_suspend(pm_message_t state)
 		if (error || async_error)
 			break;
 	}
+
 	mutex_unlock(&dpm_list_mtx);
+
 	async_synchronize_full();
 	if (!error)
 		error = async_error;