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| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2008-10-06 14:45:46 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-10-17 14:41:03 -0700 |
| commit | 49e7cc84a86784ef2ab4e651f1824093be8f5b2b (patch) | |
| tree | 0bd664b1df6cd48382bcb51771ca3eac362697ee | |
| parent | eafe5b99f2135488b21cf17a262c54997c44f784 (diff) | |
| download | linux-49e7cc84a86784ef2ab4e651f1824093be8f5b2b.tar.gz linux-49e7cc84a86784ef2ab4e651f1824093be8f5b2b.tar.bz2 linux-49e7cc84a86784ef2ab4e651f1824093be8f5b2b.zip | |
USB: Export if an interface driver supports autosuspend.
Create a new sysfs file per interface named supports_autosuspend. This
file returns true if an interface driver's .supports_autosuspend flag is
set. It also returns true if the interface is unclaimed (since the USB
core will autosuspend a device if an interface is not claimed).
This new sysfs file will be useful for user space scripts to test whether
a USB device correctly auto-suspends.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-usb | 16 | ||||
| -rw-r--r-- | drivers/usb/core/sysfs.c | 24 |
2 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index 11a3c1682cec..df6c8a0159f1 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -85,3 +85,19 @@ Description: Users: PowerTOP <power@bughost.org> http://www.lesswatts.org/projects/powertop/ + +What: /sys/bus/usb/device/<busnum>-<devnum>...:<config num>-<interface num>/supports_autosuspend +Date: January 2008 +KernelVersion: 2.6.27 +Contact: Sarah Sharp <sarah.a.sharp@intel.com> +Description: + When read, this file returns 1 if the interface driver + for this interface supports autosuspend. It also + returns 1 if no driver has claimed this interface, as an + unclaimed interface will not stop the device from being + autosuspended if all other interface drivers are idle. + The file returns 0 if autosuspend support has not been + added to the driver. +Users: + USB PM tool + git://git.moblin.org/users/sarah/usb-pm-tool/ diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 5e1f5d55bf04..f66fba11fbd5 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -743,6 +743,29 @@ static ssize_t show_modalias(struct device *dev, } static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); +static ssize_t show_supports_autosuspend(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct usb_interface *intf; + struct usb_device *udev; + int ret; + + intf = to_usb_interface(dev); + udev = interface_to_usbdev(intf); + + usb_lock_device(udev); + /* Devices will be autosuspended even when an interface isn't claimed */ + if (!intf->dev.driver || + to_usb_driver(intf->dev.driver)->supports_autosuspend) + ret = sprintf(buf, "%u\n", 1); + else + ret = sprintf(buf, "%u\n", 0); + usb_unlock_device(udev); + + return ret; +} +static DEVICE_ATTR(supports_autosuspend, S_IRUGO, show_supports_autosuspend, NULL); + static struct attribute *intf_attrs[] = { &dev_attr_bInterfaceNumber.attr, &dev_attr_bAlternateSetting.attr, @@ -751,6 +774,7 @@ static struct attribute *intf_attrs[] = { &dev_attr_bInterfaceSubClass.attr, &dev_attr_bInterfaceProtocol.attr, &dev_attr_modalias.attr, + &dev_attr_supports_autosuspend.attr, NULL, }; static struct attribute_group intf_attr_grp = { |