diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c
index d91180ab5f3b..781b6723379f 100644
--- a/drivers/usb/serial/keyspan_pda.c
+++ b/drivers/usb/serial/keyspan_pda.c
@@ -647,8 +647,12 @@ error:
 }
 static void keyspan_pda_close(struct usb_serial_port *port)
 {
+	struct keyspan_pda_private *priv = usb_get_serial_port_data(port);
+
 	usb_kill_urb(port->write_urb);
 	usb_kill_urb(port->interrupt_in_urb);
+
+	cancel_work_sync(&priv->unthrottle_work);
 }