PM: sleep: Show how long dpm_suspend_start() and dpm_suspend_end() take

When debugging device driver power management code it is convenient to
know how much time is spent in the "suspend start" and "suspend end"
phases. Hence log the time spent in these phases.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index dcfc0a36c8f7e7408867f19c296b9897e31ecc39..1e84b8aa220f2f194b883126012df28dbc8ddf86 100644 (file)
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1631,17 +1631,20 @@ int dpm_suspend_late(pm_message_t state)
  */
 int dpm_suspend_end(pm_message_t state)
 {
-       int error = dpm_suspend_late(state);
+       ktime_t starttime = ktime_get();
+       int error;
+
+       error = dpm_suspend_late(state);
        if (error)
-               return error;
+               goto out;
 
        error = dpm_suspend_noirq(state);
-       if (error) {
+       if (error)
                dpm_resume_early(resume_event(state));
-               return error;
-       }
 
-       return 0;
+out:
+       dpm_show_time(starttime, state, error, "end");
+       return error;
 }
 EXPORT_SYMBOL_GPL(dpm_suspend_end);
 
@@ -2034,6 +2037,7 @@ int dpm_prepare(pm_message_t state)
  */
 int dpm_suspend_start(pm_message_t state)
 {
+       ktime_t starttime = ktime_get();
        int error;
 
        error = dpm_prepare(state);
@@ -2042,6 +2046,7 @@ int dpm_suspend_start(pm_message_t state)
                dpm_save_failed_step(SUSPEND_PREPARE);
        } else
                error = dpm_suspend(state);
+       dpm_show_time(starttime, state, error, "start");
        return error;
 }
 EXPORT_SYMBOL_GPL(dpm_suspend_start);