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| 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 /include/linux/usb.h | |
| parent | 228426edac844a2c9270528e9cd7ab6260ef7628 (diff) | |
| download | lwn-1512300689426cb98bfd7e567ee9fdfaaf61b7c7.tar.gz lwn-1512300689426cb98bfd7e567ee9fdfaaf61b7c7.zip | |
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 'include/linux/usb.h')
| -rw-r--r-- | include/linux/usb.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h index 8aae045e9a2e..f8a60756fe2a 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -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 */ |