cfg80211: disable CSA for all drivers

The channel switch announcement code has some major locking problems
which can cause a deadlock in worst case. A series of fixes has been
proposed, but these are non-trivial and need to be tested first.
Therefore disable CSA completely for 3.13.

Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/core.c

@@ -454,6 +454,12 @@ int wiphy_register(struct wiphy *wiphy)
 	/* support for 5/10 MHz is broken due to nl80211 API mess - disable */
 	wiphy->flags &= ~WIPHY_FLAG_SUPPORTS_5_10_MHZ;
 
+	/*
+	 * There are major locking problems in nl80211/mac80211 for CSA,
+	 * disable for all drivers until this has been reworked.
+	 */
+	wiphy->flags &= ~WIPHY_FLAG_HAS_CHANNEL_SWITCH;
+
 #ifdef CONFIG_PM
 	if (WARN_ON(wiphy->wowlan &&
 		    (wiphy->wowlan->flags & WIPHY_WOWLAN_GTK_REKEY_FAILURE) &&