USB: stop io performed by mos7720 upon close()
This fixes a problem where the mos7720 driver will make io to a device from
which it has been logically disconnected. It does so by introducing a flag by
which the generic usb serial code can signal the subdrivers their
disconnection and appropriate locking.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/mos7720.c b/drivers/usb/serial/mos7720.c
index 725991f..40f3a01 100644
--- a/drivers/usb/serial/mos7720.c
+++ b/drivers/usb/serial/mos7720.c
@@ -564,22 +564,25 @@
}
/* While closing port, shutdown all bulk read, write *
- * and interrupt read if they exists */
- if (serial->dev) {
- dbg("Shutdown bulk write");
- usb_kill_urb(port->write_urb);
- dbg("Shutdown bulk read");
- usb_kill_urb(port->read_urb);
+ * and interrupt read if they exists, otherwise nop */
+ dbg("Shutdown bulk write");
+ usb_kill_urb(port->write_urb);
+ dbg("Shutdown bulk read");
+ usb_kill_urb(port->read_urb);
+
+ mutex_lock(&serial->disc_mutex);
+ /* these commands must not be issued if the device has
+ * been disconnected */
+ if (!serial->disconnected) {
+ data = 0x00;
+ send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
+ 0x04, &data);
+
+ data = 0x00;
+ send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
+ 0x01, &data);
}
-
- data = 0x00;
- send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
- 0x04, &data);
-
- data = 0x00;
- send_mos_cmd(serial, MOS_WRITE, port->number - port->serial->minor,
- 0x01, &data);
-
+ mutex_unlock(&serial->disc_mutex);
mos7720_port->open = 0;
dbg("Leaving %s", __FUNCTION__);