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authorSarah Sharp <saharabeara@gmail.com>2007-12-21 16:54:15 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2008-02-01 14:35:00 -0800
commit1512300689426cb98bfd7e567ee9fdfaaf61b7c7 (patch)
treea275493675fe7bc6b666d1c6a8179e103c7a199c /drivers/usb/core/sysfs.c
parent228426edac844a2c9270528e9cd7ab6260ef7628 (diff)
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>
Diffstat (limited to 'drivers/usb/core/sysfs.c')
-rw-r--r--drivers/usb/core/sysfs.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 32bd130b1ee..021b1d37462 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -249,6 +249,41 @@ 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)
{
struct usb_device *udev = to_usb_device(dev);
@@ -365,6 +400,14 @@ 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;
}
@@ -372,6 +415,12 @@ static int add_power_attributes(struct device *dev)
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);
sysfs_remove_file_from_group(&dev->kobj,