mac80211: send control port protocol frames to the VO queue

Improves reliability of wifi connections with WPA, since authentication
frames are prioritized over normal traffic and also typically exempt
from aggregation.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/wme.c

@@ -154,6 +154,11 @@ u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 		return IEEE80211_AC_BE;
 	}
 
+	if (skb->protocol == sdata->control_port_protocol) {
+		skb->priority = 7;
+		return ieee80211_downgrade_queue(sdata, skb);
+	}
+
 	/* use the data classifier to determine what 802.1d tag the
 	 * data frame has */
 	rcu_read_lock();