diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 63d852c..f614ee6 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -136,6 +136,14 @@
 	ieee80211_tx_skb(sdata, skb);
 }
 
+void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
+			     struct tid_ampdu_tx *tid_tx)
+{
+	lockdep_assert_held(&sta->ampdu_mlme.mtx);
+	lockdep_assert_held(&sta->lock);
+	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
+}
+
 static void kfree_tid_tx(struct rcu_head *rcu_head)
 {
 	struct tid_ampdu_tx *tid_tx =
@@ -161,7 +169,7 @@
 
 	if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
 		/* not even started yet! */
-		rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
+		ieee80211_assign_tid_tx(sta, tid, NULL);
 		spin_unlock_bh(&sta->lock);
 		call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
 		return 0;
@@ -318,7 +326,7 @@
 					" tid %d\n", tid);
 #endif
 		spin_lock_bh(&sta->lock);
-		rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
+		ieee80211_assign_tid_tx(sta, tid, NULL);
 		spin_unlock_bh(&sta->lock);
 
 		ieee80211_wake_queue_agg(local, tid);
@@ -398,7 +406,7 @@
 
 	tid_tx = sta->ampdu_mlme.tid_tx[tid];
 	/* check if the TID is not in aggregation flow already */
-	if (tid_tx) {
+	if (tid_tx || sta->ampdu_mlme.tid_start_tx[tid]) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "BA request denied - session is not "
 				 "idle on tid %u\n", tid);
@@ -433,8 +441,11 @@
 	sta->ampdu_mlme.dialog_token_allocator++;
 	tid_tx->dialog_token = sta->ampdu_mlme.dialog_token_allocator;
 
-	/* finally, assign it to the array */
-	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
+	/*
+	 * Finally, assign it to the start array; the work item will
+	 * collect it and move it to the normal array.
+	 */
+	sta->ampdu_mlme.tid_start_tx[tid] = tid_tx;
 
 	ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work);
 
@@ -697,7 +708,7 @@
 	ieee80211_agg_splice_packets(local, tid_tx, tid);
 
 	/* future packets must not find the tid_tx struct any more */
-	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
+	ieee80211_assign_tid_tx(sta, tid, NULL);
 
 	ieee80211_agg_splice_finish(local, tid);