usb-serial: ftdi_sio: fix reference counting of ftdi_private

[deliverable/linux.git] / drivers / usb / serial / ftdi_sio.c

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index aab567644b99a9438abd9f7bd6b176ec70cb0d2a..0ab8474b00cb4d69ff893fa443144e957077b2bf 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -56,6 +56,7 @@ static __u16 vendor = FTDI_VID;
 static __u16 product;
 
 struct ftdi_private {
+       struct kref kref;
        ftdi_chip_type_t chip_type;
                                /* type of device, either SIO or FT8U232AM */
        int baud_base;          /* baud base clock for divisor setting */
@@ -1354,6 +1355,7 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
                return -ENOMEM;
        }
 
+       kref_init(&priv->kref);
        spin_lock_init(&priv->rx_lock);
        spin_lock_init(&priv->tx_lock);
        init_waitqueue_head(&priv->delta_msr_wait);
@@ -1470,6 +1472,13 @@ static void ftdi_shutdown(struct usb_serial *serial)
        dbg("%s", __func__);
 }
 
+static void ftdi_sio_priv_release(struct kref *k)
+{
+       struct ftdi_private *priv = container_of(k, struct ftdi_private, kref);
+
+       kfree(priv);
+}
+
 static int ftdi_sio_port_remove(struct usb_serial_port *port)
 {
        struct ftdi_private *priv = usb_get_serial_port_data(port);
@@ -1484,7 +1493,7 @@ static int ftdi_sio_port_remove(struct usb_serial_port *port)
 
        if (priv) {
                usb_set_serial_port_data(port, NULL);
-               kfree(priv);
+               kref_put(&priv->kref, ftdi_sio_priv_release);
        }
 
        return 0;
@@ -1549,7 +1558,8 @@ static int ftdi_open(struct tty_struct *tty,
                dev_err(&port->dev,
                        "%s - failed submitting read urb, error %d\n",
                        __func__, result);
-
+       else
+               kref_get(&priv->kref);
 
        return result;
 } /* ftdi_open */
@@ -1591,11 +1601,11 @@ static void ftdi_close(struct tty_struct *tty,
        mutex_unlock(&port->serial->disc_mutex);
 
        /* cancel any scheduled reading */
-       cancel_delayed_work(&priv->rx_work);
-       flush_scheduled_work();
+       cancel_delayed_work_sync(&priv->rx_work);
 
        /* shutdown our bulk read */
        usb_kill_urb(port->read_urb);
+       kref_put(&priv->kref, ftdi_sio_priv_release);
 } /* ftdi_close */