[PATCH 4.4 034/101] USB: serial: io_ti: fix I/O after disconnect

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 2330d0a853da260d8a9834a70df448032b9ff623 upstream.

Cancel the heartbeat work on driver unbind in order to avoid I/O after
disconnect in case the port is held open.

Note that the cancel in release() is still needed to stop the heartbeat
after late probe errors.

Fixes: 26c78daade0f ("USB: io_ti: Add heartbeat to keep idle EP/416 ports from disconnecting")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/serial/io_ti.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -2593,6 +2593,9 @@ static int edge_startup(struct usb_seria
 
 static void edge_disconnect(struct usb_serial *serial)
 {
+	struct edgeport_serial *edge_serial = usb_get_serial_data(serial);
+
+	cancel_delayed_work_sync(&edge_serial->heartbeat_work);
 }
 
 static void edge_release(struct usb_serial *serial)