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 <[EMAIL PROTECTED]>
---
drivers/usb/core/hub.c | 10 ++++++++-
drivers/usb/core/sysfs.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/usb/core/usb.c | 2 +
include/linux/usb.h | 3 ++
4 files changed, 63 insertions(+), 1 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index b04d232..ea93842 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1027,8 +1027,10 @@ 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;
}
@@ -1077,6 +1079,12 @@ 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);
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 32bd130..021b1d3 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,
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 8f14237..fd35394 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -339,6 +339,8 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus
*bus, unsigned port1)
mutex_init(&dev->pm_mutex);
INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
dev->autosuspend_delay = usb_autosuspend_delay * HZ;
+ dev->connect_time = jiffies;
+ dev->active_duration = -jiffies;
#endif
if (root_hub) /* Root hub always ok [and always wired] */
dev->authorized = 1;
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 5fc8ff7..b031455 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 */
--
1.5.2.5
-
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