USB: Export suspend statistics
This patch exports two statistics to userspace:
/sys/bus/usb/device/.../power/connected_duration
/sys/bus/usb/device/.../power/active_duration
connected_duration is the total time (in msec) that the device has
been connected. active_duration is the total time the device has not
been suspended. With these two statistics, tools like PowerTOP can
calculate the percentage time that a device is active, i.e. not
suspended or auto-suspended.
Users can also use the active_duration to check if a device is actually
autosuspended. Currently, they can set power/level to auto and
power/autosuspend to a positive timeout, but there's no way to know from
userspace if a device was actually autosuspended without looking at the
dmesg output. These statistics will be useful in creating an automated
userspace script to test autosuspend for USB devices.
Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 8aae045..f8a60756 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -419,12 +419,15 @@
u32 quirks; /* quirks of the whole device */
atomic_t urbnum; /* number of URBs submitted for the whole device */
+ unsigned long active_duration; /* total time device is not suspended */
+
#ifdef CONFIG_PM
struct delayed_work autosuspend; /* for delayed autosuspends */
struct mutex pm_mutex; /* protects PM operations */
unsigned long last_busy; /* time of last use */
int autosuspend_delay; /* in jiffies */
+ unsigned long connect_time; /* time device was first connected */
unsigned auto_pm:1; /* autosuspend/resume in progress */
unsigned do_remote_wakeup:1; /* remote wakeup should be enabled */