USB: ftdi_sio: use port_probe / port_remove thereby fixing access to the latency_timer

Convert all the port specific code in attach / shutdown to use the new
port_probe / port_register callbacks from device_register /
device_unregister allowing adding the sysfs attributes to be added at
the correct time and to the serial port device itself, instead of to
the unadorned usb device, avoiding a NULL dereference.

Signed-off-by: Jim Radford <radford@blackbean.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 07884e0803b9ce1bb5430a38768a0be907f7d23b..ada4e6c6f9ccb145ad35de3d52c08f37d535f4c1 100644 (file)
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -597,6 +597,8 @@ struct ftdi_private {
 static int  ftdi_sio_probe     (struct usb_serial *serial, const struct usb_device_id *id);
 static int  ftdi_sio_attach            (struct usb_serial *serial);
 static void ftdi_shutdown              (struct usb_serial *serial);
+static int  ftdi_sio_port_probe        (struct usb_serial_port *port);
+static int  ftdi_sio_port_remove       (struct usb_serial_port *port);
 static int  ftdi_open                  (struct usb_serial_port *port, struct file *filp);
 static void ftdi_close                 (struct usb_serial_port *port, struct file *filp);
 static int  ftdi_write                 (struct usb_serial_port *port, const unsigned char *buf, int count);
@@ -631,6 +633,8 @@ static struct usb_serial_driver ftdi_sio_device = {
        .num_bulk_out =         1,
        .num_ports =            1,
        .probe =                ftdi_sio_probe,
+       .port_probe =           ftdi_sio_port_probe,
+       .port_remove =          ftdi_sio_port_remove,
        .open =                 ftdi_open,
        .close =                ftdi_close,
        .throttle =             ftdi_throttle,
@@ -1033,11 +1037,10 @@ static ssize_t show_latency_timer(struct device *dev, struct device_attribute *a
 {
        struct usb_serial_port *port = to_usb_serial_port(dev);
        struct ftdi_private *priv = usb_get_serial_port_data(port);
-       struct usb_device *udev;
+       struct usb_device *udev = port->serial->dev;
        unsigned short latency = 0;
        int rv = 0;
 
-       udev = to_usb_device(dev);
 
        dbg("%s",__FUNCTION__);
 
@@ -1061,13 +1064,11 @@ static ssize_t store_latency_timer(struct device *dev, struct device_attribute *
 {
        struct usb_serial_port *port = to_usb_serial_port(dev);
        struct ftdi_private *priv = usb_get_serial_port_data(port);
-       struct usb_device *udev;
+       struct usb_device *udev = port->serial->dev;
        char buf[1];
        int v = simple_strtoul(valbuf, NULL, 10);
        int rv = 0;
 
-       udev = to_usb_device(dev);
-
        dbg("%s: setting latency timer = %i", __FUNCTION__, v);
 
        rv = usb_control_msg(udev,
@@ -1092,13 +1093,11 @@ static ssize_t store_event_char(struct device *dev, struct device_attribute *att
 {
        struct usb_serial_port *port = to_usb_serial_port(dev);
        struct ftdi_private *priv = usb_get_serial_port_data(port);
-       struct usb_device *udev;
+       struct usb_device *udev = port->serial->dev;
        char buf[1];
        int v = simple_strtoul(valbuf, NULL, 10);
        int rv = 0;
 
-       udev = to_usb_device(dev);
-
        dbg("%s: setting event char = %i", __FUNCTION__, v);
 
        rv = usb_control_msg(udev,
@@ -1119,46 +1118,38 @@ static ssize_t store_event_char(struct device *dev, struct device_attribute *att
 static DEVICE_ATTR(latency_timer, S_IWUSR | S_IRUGO, show_latency_timer, store_latency_timer);
 static DEVICE_ATTR(event_char, S_IWUSR, NULL, store_event_char);
 
-static int create_sysfs_attrs(struct usb_serial *serial)
+static int create_sysfs_attrs(struct usb_serial_port *port)
 {
-       struct ftdi_private *priv;
-       struct usb_device *udev;
+       struct ftdi_private *priv = usb_get_serial_port_data(port);
        int retval = 0;
 
        dbg("%s",__FUNCTION__);
 
-       priv = usb_get_serial_port_data(serial->port[0]);
-       udev = serial->dev;
-
        /* XXX I've no idea if the original SIO supports the event_char
         * sysfs parameter, so I'm playing it safe.  */
        if (priv->chip_type != SIO) {
                dbg("sysfs attributes for %s", ftdi_chip_name[priv->chip_type]);
-               retval = device_create_file(&udev->dev, &dev_attr_event_char);
+               retval = device_create_file(&port->dev, &dev_attr_event_char);
                if ((!retval) &&
                    (priv->chip_type == FT232BM || priv->chip_type == FT2232C)) {
-                       retval = device_create_file(&udev->dev,
+                       retval = device_create_file(&port->dev,
                                                    &dev_attr_latency_timer);
                }
        }
        return retval;
 }
 
-static void remove_sysfs_attrs(struct usb_serial *serial)
+static void remove_sysfs_attrs(struct usb_serial_port *port)
 {
-       struct ftdi_private *priv;
-       struct usb_device *udev;
+       struct ftdi_private *priv = usb_get_serial_port_data(port);
 
        dbg("%s",__FUNCTION__);
 
-       priv = usb_get_serial_port_data(serial->port[0]);
-       udev = serial->dev;
-
        /* XXX see create_sysfs_attrs */
        if (priv->chip_type != SIO) {
-               device_remove_file(&udev->dev, &dev_attr_event_char);
+               device_remove_file(&port->dev, &dev_attr_event_char);
                if (priv->chip_type == FT232BM || priv->chip_type == FT2232C) {
-                       device_remove_file(&udev->dev, &dev_attr_latency_timer);
+                       device_remove_file(&port->dev, &dev_attr_latency_timer);
                }
        }
 
@@ -1178,13 +1169,9 @@ static int ftdi_sio_probe (struct usb_serial *serial, const struct usb_device_id
        return (0);
 }
 
-/* attach subroutine */
-static int ftdi_sio_attach (struct usb_serial *serial)
+static int ftdi_sio_port_probe(struct usb_serial_port *port)
 {
-       struct usb_serial_port *port = serial->port[0];
        struct ftdi_private *priv;
-       struct ftdi_sio_quirk *quirk;
-       int retval;
 
        dbg("%s",__FUNCTION__);
 
@@ -1224,19 +1211,21 @@ static int ftdi_sio_attach (struct usb_serial *serial)
        kfree(port->bulk_out_buffer);
        port->bulk_out_buffer = NULL;
 
-       usb_set_serial_port_data(serial->port[0], priv);
+       usb_set_serial_port_data(port, priv);
 
-       ftdi_determine_type (serial->port[0]);
-       retval = create_sysfs_attrs(serial);
-       if (retval)
-               dev_err(&serial->dev->dev, "Error creating sysfs files, "
-                       "continuing\n");
+       ftdi_determine_type (port);
+       create_sysfs_attrs(port);
+       return 0;
+}
 
+/* attach subroutine */
+static int ftdi_sio_attach (struct usb_serial *serial)
+{
        /* Check for device requiring special set up. */
-       quirk = (struct ftdi_sio_quirk *)usb_get_serial_data(serial);
-       if (quirk && quirk->setup) {
+       struct ftdi_sio_quirk *quirk = usb_get_serial_data(serial);
+
+       if (quirk && quirk->setup)
                quirk->setup(serial);
-       }
 
        return 0;
 } /* ftdi_sio_attach */
@@ -1280,17 +1269,18 @@ static void ftdi_HE_TIRA1_setup (struct usb_serial *serial)
  *      calls __serial_close for each open of the port
  *      shutdown is called then (ie ftdi_shutdown)
  */
-
-
 static void ftdi_shutdown (struct usb_serial *serial)
-{ /* ftdi_shutdown */
+{
+       dbg("%s", __FUNCTION__);
+}
 
-       struct usb_serial_port *port = serial->port[0];
+static int ftdi_sio_port_remove(struct usb_serial_port *port)
+{
        struct ftdi_private *priv = usb_get_serial_port_data(port);
 
        dbg("%s", __FUNCTION__);
 
-       remove_sysfs_attrs(serial);
+       remove_sysfs_attrs(port);
 
        /* all open ports are closed at this point
          *    (by usbserial.c:__serial_close, which calls ftdi_close)
@@ -1300,8 +1290,9 @@ static void ftdi_shutdown (struct usb_serial *serial)
                usb_set_serial_port_data(port, NULL);
                kfree(priv);
        }
-} /* ftdi_shutdown */
 
+       return 0;
+}
 
 static int  ftdi_open (struct usb_serial_port *port, struct file *filp)
 { /* ftdi_open */