On Wed, Apr 29, 2009 at 12:00:58PM -0400, Alan Stern wrote:
> On Wed, 29 Apr 2009, Alan Stern wrote:
>
> > Looks like the ftdi_sio driver doesn't use proper reference counting
> > for its private data structure. Does this patch help?
>
> Oops, I forgot to initialize the kref. Try this patch instead.
Yep, that did it! Very good, thanks a lot.
Feel free to add my 'Tested-by' :)
Daniel
> Index: 2.6.30-rc3/drivers/usb/serial/ftdi_sio.c
> ===================================================================
> --- 2.6.30-rc3.orig/drivers/usb/serial/ftdi_sio.c
> +++ 2.6.30-rc3/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 */
> @@ -1352,6 +1353,7 @@ static int ftdi_sio_port_probe(struct us
> 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);
> @@ -1468,6 +1470,13 @@ static void ftdi_shutdown(struct usb_ser
> 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);
> @@ -1482,7 +1491,7 @@ static int ftdi_sio_port_remove(struct u
>
> if (priv) {
> usb_set_serial_port_data(port, NULL);
> - kfree(priv);
> + kref_put(&priv->kref, ftdi_sio_priv_release);
> }
>
> return 0;
> @@ -1547,7 +1556,8 @@ static int ftdi_open(struct tty_struct *
> dev_err(&port->dev,
> "%s - failed submitting read urb, error %d\n",
> __func__, result);
> -
> + else
> + kref_get(&priv->kref);
>
> return result;
> } /* ftdi_open */
> @@ -1589,11 +1599,11 @@ static void ftdi_close(struct tty_struct
> 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 */
>
>
>
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