The tty may be closed already when the read/write callbacks are called.
This patch checks that the ttys still exist before waking them up.
Signed-off-by: Olivier Blin <blino@mandriva.com>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Jari Tenhunen <jari.tenhunen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
                return;
        }
        hso_put_activity(serial->parent);
-       tty_wakeup(serial->tty);
+       if (serial->tty)
+               tty_wakeup(serial->tty);
        hso_kick_transmit(serial);
 
        D1(" ");
                        clear_bit(HSO_SERIAL_FLAG_RX_SENT, &serial->flags);
        } else {
                hso_put_activity(serial->parent);
-               tty_wakeup(serial->tty);
+               if (serial->tty)
+                       tty_wakeup(serial->tty);
                /* response to a write command */
                hso_kick_transmit(serial);
        }