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/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 28315b0..3ce98e8 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -634,6 +634,7 @@
serial->type = driver;
serial->interface = interface;
kref_init(&serial->kref);
+ mutex_init(&serial->disc_mutex);
return serial;
}
@@ -1089,20 +1090,22 @@
usb_serial_console_disconnect(serial);
dbg ("%s", __FUNCTION__);
+ mutex_lock(&serial->disc_mutex);
usb_set_intfdata (interface, NULL);
- if (serial) {
- for (i = 0; i < serial->num_ports; ++i) {
- port = serial->port[i];
- if (port) {
- if (port->tty)
- tty_hangup(port->tty);
- kill_traffic(port);
- }
+ /* must set a flag, to signal subdrivers */
+ serial->disconnected = 1;
+ for (i = 0; i < serial->num_ports; ++i) {
+ port = serial->port[i];
+ if (port) {
+ if (port->tty)
+ tty_hangup(port->tty);
+ kill_traffic(port);
}
- /* let the last holder of this object
- * cause it to be cleaned up */
- usb_serial_put(serial);
}
+ /* let the last holder of this object
+ * cause it to be cleaned up */
+ mutex_unlock(&serial->disc_mutex);
+ usb_serial_put(serial);
dev_info(dev, "device disconnected\n");
}
@@ -1112,9 +1115,6 @@
struct usb_serial_port *port;
int i, r = 0;
- if (!serial) /* device has been disconnected */
- return 0;
-
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
if (port)
