mac80211: update A-MPDU flag on tx dequeue

The sequence number counter is used to derive the starting sequence
number. Since that counter is updated on tx dequeue, the A-MPDU flag
needs to be up to date at the tme of dequeue as well.

This patch prevents sending more A-MPDU frames after the session has
been terminated and also ensures that aggregation starts right after the
session has been established

Fixes: bb42f2d1 ("mac80211: Move reorder-sensitive TX handlers to after TXQ dequeue")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/tx.c

@@ -3426,6 +3426,11 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
 		goto begin;
 	}
 
+	if (test_bit(IEEE80211_TXQ_AMPDU, &txqi->flags))
+		info->flags |= IEEE80211_TX_CTL_AMPDU;
+	else
+		info->flags &= ~IEEE80211_TX_CTL_AMPDU;
+
 	if (info->control.flags & IEEE80211_TX_CTRL_FAST_XMIT) {
 		struct sta_info *sta = container_of(txq->sta, struct sta_info,
 						    sta);