PM / sleep: Mark suspend/hibernation start and finish

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@intel.com>
Acked-by: Mark Salyzyn <salyzyn@android.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index e19ee179d211..a5c36e9c56a6 100644
--- a/kernel/power/hibernate.c
+++ b/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:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 4f10773322fa..18cdb1596d27 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -584,6 +584,7 @@ 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++;
@@ -591,6 +592,7 @@ int pm_suspend(suspend_state_t state)
         } else {
                 suspend_stats.success++;
         }
+        pr_info("PM: suspend exit\n");
         return error;
 }
 EXPORT_SYMBOL(pm_suspend);