diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index eab84c1..9b819c4 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -223,7 +223,6 @@ struct moschip_port {
 	__u8 shadowMCR;		/* last MCR value received */
 	char open;
 	char open_ports;
-	char zombie;
 	wait_queue_head_t wait_chase;	/* for handling sleeping while waiting for chase to finish */
 	wait_queue_head_t delta_msr_wait;	/* for handling sleeping while waiting for msr change to happen */
 	int delta_msr_cond;
@@ -692,14 +691,7 @@ static void mos7840_interrupt_callback(struct urb *urb)
 					wreg = MODEM_STATUS_REGISTER;
 					break;
 				}
-				spin_lock(&mos7840_port->pool_lock);
-				if (!mos7840_port->zombie) {
-					rv = mos7840_get_reg(mos7840_port, wval, wreg, &Data);
-				} else {
-					spin_unlock(&mos7840_port->pool_lock);
-					return;
-				}
-				spin_unlock(&mos7840_port->pool_lock);
+				rv = mos7840_get_reg(mos7840_port, wval, wreg, &Data);
 			}
 		}
 	}
@@ -2701,9 +2693,6 @@ static void mos7840_disconnect(struct usb_serial *serial)
 		mos7840_port = mos7840_get_port_private(serial->port[i]);
 		dbg ("mos7840_port %d = %p", i, mos7840_port);
 		if (mos7840_port) {
-			spin_lock_irqsave(&mos7840_port->pool_lock, flags);
-			mos7840_port->zombie = 1;
-			spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
 			usb_kill_urb(mos7840_port->control_urb);
 		}
 	}