rt2x00: Block adhoc & master mode

rt2x00 is broken when it comes down to adhoc and master mode.
The main problem is the beaconing, which is completely failing.
Untill a solution has been found, both beacon requiring modes
must be disabled to prevent numerous bug reports.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2x00mac.c

@@ -196,6 +196,14 @@ int rt2x00mac_add_interface(struct ieee80211_hw *hw,
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 	struct interface *intf = &rt2x00dev->interface;
 
+	/* FIXME: Beaconing is broken in rt2x00. */
+	if (conf->type == IEEE80211_IF_TYPE_IBSS ||
+	    conf->type == IEEE80211_IF_TYPE_AP) {
+		ERROR(rt2x00dev,
+		      "rt2x00 does not support Adhoc or Master mode");
+		return -EOPNOTSUPP;
+	}
+
 	/*
 	 * Don't allow interfaces to be added while
 	 * either the device has disappeared or when