Commit 15123006 authored by Sarah Sharp's avatar Sarah Sharp Committed by Greg Kroah-Hartman
Browse files

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: default avatarSarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 228426ed

drivers/usb/core/hub.c

+9 −1
Original line number Diff line number Diff line
@@ -1034,8 +1034,10 @@ static void recursively_mark_NOTATTACHED(struct usb_device *udev) 
		if (udev->children[i])

			recursively_mark_NOTATTACHED(udev->children[i]);

	}

	if (udev->state == USB_STATE_SUSPENDED)

	if (udev->state == USB_STATE_SUSPENDED) {

		udev->discon_suspended = 1;

		udev->active_duration -= jiffies;

	}

	udev->state = USB_STATE_NOTATTACHED;

}
@@ -1084,6 +1086,12 @@ void usb_set_device_state(struct usb_device *udev, 
			else

				device_init_wakeup(&udev->dev, 0);

		}

		if (udev->state == USB_STATE_SUSPENDED &&

			new_state != USB_STATE_SUSPENDED)

			udev->active_duration -= jiffies;

		else if (new_state == USB_STATE_SUSPENDED &&

				udev->state != USB_STATE_SUSPENDED)

			udev->active_duration += jiffies;

		udev->state = new_state;

	} else

		recursively_mark_NOTATTACHED(udev);

drivers/usb/core/sysfs.c

+49 −0
Original line number Diff line number Diff line
@@ -248,6 +248,41 @@ static void remove_persist_attributes(struct device *dev) 


#ifdef	CONFIG_USB_SUSPEND



static ssize_t

show_connected_duration(struct device *dev, struct device_attribute *attr,

		char *buf)

{

	struct usb_device *udev = to_usb_device(dev);



	return sprintf(buf, "%u\n",

			jiffies_to_msecs(jiffies - udev->connect_time));

}



static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);



/*

 * If the device is resumed, the last time the device was suspended has

 * been pre-subtracted from active_duration.  We add the current time to

 * get the duration that the device was actually active.

 *

 * If the device is suspended, the active_duration is up-to-date.

 */

static ssize_t

show_active_duration(struct device *dev, struct device_attribute *attr,

		char *buf)

{

	struct usb_device *udev = to_usb_device(dev);

	int duration;



	if (udev->state != USB_STATE_SUSPENDED)

		duration = jiffies_to_msecs(jiffies + udev->active_duration);

	else

		duration = jiffies_to_msecs(udev->active_duration);

	return sprintf(buf, "%u\n", duration);

}



static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);



static ssize_t

show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)

{
@@ -365,12 +400,26 @@ static int add_power_attributes(struct device *dev) 
			rc = sysfs_add_file_to_group(&dev->kobj,

					&dev_attr_level.attr,

					power_group);

		if (rc == 0)

			rc = sysfs_add_file_to_group(&dev->kobj,

					&dev_attr_connected_duration.attr,

					power_group);

		if (rc == 0)

			rc = sysfs_add_file_to_group(&dev->kobj,

					&dev_attr_active_duration.attr,

					power_group);

	}

	return rc;

}



static void remove_power_attributes(struct device *dev)

{

	sysfs_remove_file_from_group(&dev->kobj,

			&dev_attr_active_duration.attr,

			power_group);

	sysfs_remove_file_from_group(&dev->kobj,

			&dev_attr_connected_duration.attr,

			power_group);

	sysfs_remove_file_from_group(&dev->kobj,

			&dev_attr_level.attr,

			power_group);

drivers/usb/core/usb.c

+2 −0
Original line number Diff line number Diff line
@@ -339,6 +339,8 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) 
	mutex_init(&dev->pm_mutex);

	INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);

	dev->autosuspend_delay = usb_autosuspend_delay * HZ;

	dev->connect_time = jiffies;

	dev->active_duration = -jiffies;

#endif

	if (root_hub)	/* Root hub always ok [and always wired] */

		dev->authorized = 1;

include/linux/usb.h

+3 −0
Original line number Diff line number Diff line
@@ -419,12 +419,15 @@ struct usb_device { 
	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 */

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