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Sarah Sharp authored
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>
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