1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
index 953bdf8827d2..4c925e3e8a63 100644
--- a/drivers/usb/serial/sierra.c
+++ b/drivers/usb/serial/sierra.c
@@ -597,7 +597,10 @@ static void sierra_close(struct usb_serial_port *port, struct file *filp)
         portdata->dtr_state = 0;
 
         if (serial->dev) {
-                sierra_send_setup(port);
+                mutex_lock(&serial->disc_mutex);
+                if (!serial->disconnected)
+                        sierra_send_setup(port);
+                mutex_unlock(&serial->disc_mutex);
 
                 /* Stop reading/writing urbs */
                 for (i = 0; i < N_IN_URB; i++)