From 1512300689426cb98bfd7e567ee9fdfaaf61b7c7 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Fri, 21 Dec 2007 16:54:15 -0800 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/sysfs.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'drivers/usb/core/sysfs.c') 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 @@ -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); -- cgit v1.2.3-18-g5258