+static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
+ struct sk_buff *skb,
+ struct ieee80211_tx_info *info,
+ struct tid_ampdu_tx *tid_tx,
+ int tid)
+{
+ bool queued = false;
+
+ if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
+ info->flags |= IEEE80211_TX_CTL_AMPDU;
+ } else {
+ spin_lock(&tx->sta->lock);
+ /*
+ * Need to re-check now, because we may get here
+ *
+ * 1) in the window during which the setup is actually
+ * already done, but not marked yet because not all
+ * packets are spliced over to the driver pending
+ * queue yet -- if this happened we acquire the lock
+ * either before or after the splice happens, but
+ * need to recheck which of these cases happened.
+ *
+ * 2) during session teardown, if the OPERATIONAL bit
+ * was cleared due to the teardown but the pointer
+ * hasn't been assigned NULL yet (or we loaded it
+ * before it was assigned) -- in this case it may
+ * now be NULL which means we should just let the
+ * packet pass through because splicing the frames
+ * back is already done.
+ */
+ tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
+
+ if (!tid_tx) {
+ /* do nothing, let packet pass through */
+ } else if (test_bit(HT_AGG_STATE_OPERATIONAL, &tid_tx->state)) {
+ info->flags |= IEEE80211_TX_CTL_AMPDU;
+ } else {
+ queued = true;
+ info->control.vif = &tx->sdata->vif;
+ info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
+ __skb_queue_tail(&tid_tx->pending, skb);
+ }
+ spin_unlock(&tx->sta->lock);
+ }
+
+ return queued;
+}
+