pegasus: add blacklist support to fix Belkin bluetooth dongle.

Reference: https://launchpad.net/bugs/140511

The Belkin bluetooth dongle unfortunately shares the vendor and device id
with the network adapter which causes lockups whenever the bluetooth
dongle is inserted.
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Ben Collins <ben.collins@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/usb/pegasus.c

@@ -1285,6 +1285,21 @@ static void check_carrier(struct work_struct *work)
 	}
 }
 
+static int pegasus_blacklisted(struct usb_device *udev)
+{
+	struct usb_device_descriptor *udd = &udev->descriptor;
+
+	/* Special quirk to keep the driver from handling the Belkin Bluetooth
+	 * dongle which happens to have the same ID.
+	 */
+	if ((udd->idVendor == VENDOR_BELKIN && udd->idProduct == 0x0121) &&
+	    (udd->bDeviceClass == USB_CLASS_WIRELESS_CONTROLLER) &&
+	    (udd->bDeviceProtocol == 1))
+		return 1;
+
+	return 0;
+}
+
 static int pegasus_probe(struct usb_interface *intf,
 			 const struct usb_device_id *id)
 {
@@ -1296,6 +1311,12 @@ static int pegasus_probe(struct usb_interface *intf,
 	DECLARE_MAC_BUF(mac);
 
 	usb_get_dev(dev);
+
+	if (pegasus_blacklisted(dev)) {
+		res = -ENODEV;
+		goto out;
+	}
+
 	net = alloc_etherdev(sizeof(struct pegasus));
 	if (!net) {
 		dev_err(&intf->dev, "can't allocate %s\n", "device");