USB: opticon: fix abuse of interface data

Fix abuse of interface data which was used to signal device disconnect.

Use the usb_serial disconnect flag and mutex where appropriate.

Note that tiocmget does not need to check for disconnect as it does not
access the device.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/drivers/usb/serial/opticon.c b/drivers/usb/serial/opticon.c
index 82cc9d202b83..d31e997ebd27 100644
--- a/drivers/usb/serial/opticon.c
+++ b/drivers/usb/serial/opticon.c
@@ -401,8 +401,6 @@ static int opticon_tiocmget(struct tty_struct *tty)
         int result = 0;
 
         dbg("%s - port %d", __func__, port->number);
-        if (!usb_get_intfdata(port->serial->interface))
-                return -ENODEV;
 
         spin_lock_irqsave(&priv->lock, flags);
         if (priv->rts)
@@ -419,13 +417,13 @@ static int opticon_tiocmset(struct tty_struct *tty,
                            unsigned int set, unsigned int clear)
 {
         struct usb_serial_port *port = tty->driver_data;
+        struct usb_serial *serial = port->serial;
         struct opticon_private *priv = usb_get_serial_data(port->serial);
         unsigned long flags;
         bool rts;
         bool changed = false;
+        int ret;
 
-        if (!usb_get_intfdata(port->serial->interface))
-                return -ENODEV;
         /* We only support RTS so we only handle that */
         spin_lock_irqsave(&priv->lock, flags);
 
@@ -441,7 +439,14 @@ static int opticon_tiocmset(struct tty_struct *tty,
                 return 0;
 
         /* Send the new RTS state to the connected device */
-        return send_control_msg(port, CONTROL_RTS, !rts);
+        mutex_lock(&serial->disc_mutex);
+        if (!serial->disconnected)
+                ret = send_control_msg(port, CONTROL_RTS, !rts);
+        else
+                ret = -ENODEV;
+        mutex_unlock(&serial->disc_mutex);
+
+        return ret;
 }
 
 static int get_serial_info(struct opticon_private *priv,