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>
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power
index 31725ff..2177726 100644
--- a/Documentation/ABI/testing/sysfs-power
+++ b/Documentation/ABI/testing/sysfs-power
@@ -231,3 +231,16 @@
Reads from this file return a string consisting of the names of
wakeup sources created with the help of /sys/power/wake_lock
that are inactive at the moment, separated with spaces.
+
+What: /sys/power/pm_print_times
+Date: May 2012
+Contact: Sameer Nanda <snanda@chromium.org>
+Description:
+ The /sys/power/pm_print_times file allows user space to
+ control whether the time taken by devices to suspend and
+ resume is printed. These prints are useful for hunting down
+ devices that take too long to suspend or resume.
+
+ Writing a "1" enables this printing while writing a "0"
+ disables it. The default value is "0". Reading from this file
+ will display the current value.