diff options
| author | Sarah Sharp <saharabeara@gmail.com> | 2007-12-21 16:54:15 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-02-01 14:35:00 -0800 |
| commit | 1512300689426cb98bfd7e567ee9fdfaaf61b7c7 (patch) | |
| tree | a275493675fe7bc6b666d1c6a8179e103c7a199c /drivers/usb/core/sysfs.c | |
| parent | 228426edac844a2c9270528e9cd7ab6260ef7628 (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.c | 49 |
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, |