USB: usb-skeleton.c: fix compilation error and restored kref_put on fail in skel_open

Fixing compilaton error.
Incrementing usage counter only on successful execution of skel_open.
Removing redundant locking

Some last changes in function skel_open and finally commit
52a7499 Revert "USB: usb-skeleton.c: fix open/disconnect race"
introduced a bug in function skel_open, which this patch fixes.

Changes since v2:
- refactoring
- Removing redundant mutex synchronization.

Changes since v1:
- Fixed accordingly feedback of Oliver Neukum oneukum@suse.de: also need to drop the lock.

Signed-off-by: Constantine Shulyupin <const@MakeLinux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 0616f23..ce31017 100644 (file)
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -105,20 +105,15 @@ static int skel_open(struct inode *inode, struct file *file)
                goto exit;
        }
 
-       /* increment our usage count for the device */
-       kref_get(&dev->kref);
-
-       /* lock the device to allow correctly handling errors
-        * in resumption */
-       mutex_lock(&dev->io_mutex);
-
        retval = usb_autopm_get_interface(interface);
        if (retval)
-               goto out_err;
+               goto exit;
+
+       /* increment our usage count for the device */
+       kref_get(&dev->kref);
 
        /* save our object in the file's private structure */
        file->private_data = dev;
-       mutex_unlock(&dev->io_mutex);
 
 exit:
        return retval;