usbcore: non-hub-specific uses of autosuspend

This patch (as741) makes the non-hub parts of usbcore actually use the
autosuspend facilities added by an earlier patch.

	Devices opened through usbfs are autoresumed and then
	autosuspended upon close.

	Likewise for usb-skeleton.

	Devices are autoresumed for usb_set_configuration.


Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 9b542a6ba97..1b51d3187a9 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -90,6 +90,11 @@ static int skel_open(struct inode *inode, struct file *file)
                 goto exit;
         }
 
+        /* prevent the device from being autosuspended */
+        retval = usb_autopm_get_interface(interface);
+        if (retval)
+                goto exit;
+
         /* increment our usage count for the device */
         kref_get(&dev->kref);
 
@@ -108,6 +113,12 @@ static int skel_release(struct inode *inode, struct file *file)
         if (dev == NULL)
                 return -ENODEV;
 
+        /* allow the device to be autosuspended */
+        mutex_lock(&dev->io_mutex);
+        if (dev->interface)
+                usb_autopm_put_interface(dev->interface);
+        mutex_unlock(&dev->io_mutex);
+
         /* decrement the count on our device */
         kref_put(&dev->kref, skel_delete);
         return 0;