[PATCH v2 2/3] PM / sleep: Mark suspend/hibernation start and finish

From: Rafael J. Wysocki
Date: Wed Jul 19 2017 - 21:46:06 EST


From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Regardless of whether or not debug messages from the core system
suspend/hibernation code are enabled, it is useful to know when
system-wide transitions start and finish (or fail), so print "info"
messages at these points.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---

-> v2: Smiplified the messages as suggested by Mark.

---
kernel/power/hibernate.c | 5 +++++
kernel/power/suspend.c | 2 ++
2 files changed, 7 insertions(+)

Index: linux-pm/kernel/power/hibernate.c
===================================================================
--- linux-pm.orig/kernel/power/hibernate.c
+++ linux-pm/kernel/power/hibernate.c
@@ -692,6 +692,7 @@ int hibernate(void)
goto Unlock;
}

+ pr_info("hibernation entry\n");
pm_prepare_console();
error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
if (error) {
@@ -762,6 +763,8 @@ int hibernate(void)
atomic_inc(&snapshot_device_available);
Unlock:
unlock_system_sleep();
+ pr_info("hibernation exit\n");
+
return error;
}

@@ -868,6 +871,7 @@ static int software_resume(void)
goto Unlock;
}

+ pr_info("resume from hibernation\n");
pm_prepare_console();
error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
if (error) {
@@ -884,6 +888,7 @@ static int software_resume(void)
Finish:
__pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
pm_restore_console();
+ pr_info("resume from hibernation failed (%d)\n", error);
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
Index: linux-pm/kernel/power/suspend.c
===================================================================
--- linux-pm.orig/kernel/power/suspend.c
+++ linux-pm/kernel/power/suspend.c
@@ -579,6 +579,7 @@ int pm_suspend(suspend_state_t state)
if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
return -EINVAL;

+ pr_info("PM: suspend entry (%s)\n", pm_states[state]);
error = enter_state(state);
if (error) {
suspend_stats.fail++;
@@ -586,6 +587,7 @@ int pm_suspend(suspend_state_t state)
} else {
suspend_stats.success++;
}
+ pr_info("PM: suspend exit\n");
return error;
}
EXPORT_SYMBOL(pm_suspend);