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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/hub.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/hub.c')
-rw-r--r--drivers/usb/core/hub.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index cc93aa9336f..53fe049b40f 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1034,8 +1034,10 @@ static void recursively_mark_NOTATTACHED(struct usb_device *udev)
if (udev->children[i])
recursively_mark_NOTATTACHED(udev->children[i]);
}
- if (udev->state == USB_STATE_SUSPENDED)
+ if (udev->state == USB_STATE_SUSPENDED) {
udev->discon_suspended = 1;
+ udev->active_duration -= jiffies;
+ }
udev->state = USB_STATE_NOTATTACHED;
}
@@ -1084,6 +1086,12 @@ void usb_set_device_state(struct usb_device *udev,
else
device_init_wakeup(&udev->dev, 0);
}
+ if (udev->state == USB_STATE_SUSPENDED &&
+ new_state != USB_STATE_SUSPENDED)
+ udev->active_duration -= jiffies;
+ else if (new_state == USB_STATE_SUSPENDED &&
+ udev->state != USB_STATE_SUSPENDED)
+ udev->active_duration += jiffies;
udev->state = new_state;
} else
recursively_mark_NOTATTACHED(udev);