[PATCH v2] PM: dpm_show_time changes to suspend/resume dmesg prints

[Todd Brandt <todd.e.brandt@linux.intel.com>]

Organize the optional dpm_show_time prints to focus on the 8 possible
suspend/resume callbacks devices can use and their associated phases
when they're called in suspend:

Remove "start suspend" as it is currently a combination of "suspend" and
"suspend prepare". Replace it with "prepare suspend" as a separate print.
Add "complete resume" over the dpm_complete call. For example:

[   66.680479] PM: suspend entry (s2idle)
[   66.826646] PM: prepare suspend of devices complete after 114.081 msecs
[   67.119306] PM: suspend of devices complete after 292.639 msecs
[   67.121309] PM: late suspend of devices complete after 1.983 msecs
[   67.190184] PM: noirq suspend of devices complete after 68.309 msecs
[   81.227706] PM: noirq resume of devices complete after 49.196 msecs
[   81.230847] PM: early resume of devices complete after 2.922 msecs
[   82.444735] PM: resume of devices complete after 1213.869 msecs
[   82.447943] PM: complete resume of devices complete after 2.850 msecs
[   82.457131] PM: suspend exit

v2 change: replace error variable with NULL in dpm_complete

Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
---
 drivers/base/power/main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index e130da428141..7496f76bf9f8 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1329,6 +1329,7 @@ static void device_complete(struct device *dev, pm_message_t state)
 void dpm_complete(pm_message_t state)
 {
 	struct list_head list;
+	ktime_t starttime = ktime_get();
 
 	trace_suspend_resume(TPS("dpm_complete"), state.event, true);
 
@@ -1358,6 +1359,7 @@ void dpm_complete(pm_message_t state)
 	thermal_pm_complete();
 	/* Allow device probing and trigger re-probing of deferred devices */
 	device_unblock_probing();
+	dpm_show_time(starttime, state, NULL, "complete");
 	trace_suspend_resume(TPS("dpm_complete"), state.event, false);
 }
 
@@ -2352,6 +2354,7 @@ int dpm_suspend_start(pm_message_t state)
 	int error;
 
 	error = dpm_prepare(state);
+	dpm_show_time(starttime, state, error, "prepare");
 	if (error)
 		dpm_save_failed_step(SUSPEND_PREPARE);
 	else {
@@ -2359,7 +2362,6 @@ int dpm_suspend_start(pm_message_t state)
 		error = dpm_suspend(state);
 	}
 
-	dpm_show_time(starttime, state, error, "start");
 	return error;
 }
 EXPORT_SYMBOL_GPL(dpm_suspend_start);
-- 
2.34.1