PM / Sleep: add knob for printing device resume times

Added a new knob called /sys/power/pm_print_times. Setting it to 1
enables printing of time taken by devices to suspend and resume.
Setting it to 0 disables this printing (unless overridden by
initcall_debug kernel command line option).

Signed-off-by: Sameer Nanda <snanda@chromium.org>
Acked-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

2 files changed, 13 insertions, 2 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 9cb845e49334..6e4db96958d1 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -166,7 +166,7 @@ static ktime_t initcall_debug_start(struct device *dev)
 {
         ktime_t calltime = ktime_set(0, 0);
 
-        if (initcall_debug) {
+        if (pm_print_times) {
                 pr_info("calling  %s+ @ %i, parent: %s\n",
                         dev_name(dev), task_pid_nr(current),
                         dev->parent ? dev_name(dev->parent) : "none");
@@ -181,7 +181,7 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime,
 {
         ktime_t delta, rettime;
 
-        if (initcall_debug) {
+        if (pm_print_times) {
                 rettime = ktime_get();
                 delta = ktime_sub(rettime, calltime);
                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h
index eeb4bff9505c..12c77b7ff8e8 100644
--- a/drivers/base/power/power.h
+++ b/drivers/base/power/power.h
@@ -85,3 +85,14 @@ static inline int pm_qos_sysfs_add(struct device *dev) { return 0; }
 static inline void pm_qos_sysfs_remove(struct device *dev) {}
 
 #endif
+
+#ifdef CONFIG_PM_DEBUG
+
+extern int pm_print_times_enabled;
+#define pm_print_times (initcall_debug || pm_print_times_enabled)
+
+#else /* CONFIG_PM_DEBUG */
+
+#define pm_print_times initcall_debug
+
+#endif /* CONFIG_PM_DEBUG */