[PATCH 4.4 62/79] USB: legousbtower: fix open after failed reset request

[Greg Kroah-Hartman]

From: Johan Hovold <johan@xxxxxxxxxx>

commit 0b074f6986751361ff442bc1127c1648567aa8d6 upstream.

The driver would return with a nonzero open count in case the reset
control request failed. This would prevent any further attempts to open
the char dev until the device was disconnected.

Fix this by incrementing the open count only on successful open.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20190919083039.30898-5-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/misc/legousbtower.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -354,7 +354,6 @@ static int tower_open (struct inode *ino
 		retval = -EBUSY;
 		goto unlock_exit;
 	}
-	dev->open_count = 1;
 
 	/* reset the tower */
 	result = usb_control_msg (dev->udev,
@@ -394,13 +393,14 @@ static int tower_open (struct inode *ino
 		dev_err(&dev->udev->dev,
 			"Couldn't submit interrupt_in_urb %d\n", retval);
 		dev->interrupt_in_running = 0;
-		dev->open_count = 0;
 		goto unlock_exit;
 	}
 
 	/* save device in the file's private structure */
 	file->private_data = dev;
 
+	dev->open_count = 1;
+
 unlock_exit:
 	mutex_unlock(&dev->lock);