diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index ecab934dc8d95b330a623727dcb51e04a0cb0773..a990338a766eb95e53695441d0d375d5806292ad 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3047,9 +3047,11 @@ enum ieee80211_reconfig_type {
  * 	ieee80211_ampdu_mlme_action. Starting sequence number (@ssn)
  * 	is the first frame we expect to perform the action on. Notice
  * 	that TX/RX_STOP can pass NULL for this parameter.
- *	The @buf_size parameter is only valid when the action is set to
- *	%IEEE80211_AMPDU_TX_OPERATIONAL and indicates the peer's reorder
- *	buffer size (number of subframes) for this session -- the driver
+ *	The @buf_size parameter is valid only when the action is set to
+ *	%IEEE80211_AMPDU_RX_START or %IEEE80211_AMPDU_TX_OPERATIONAL and
+ *	indicates the reorder buffer size (number of subframes) for this
+ *	session.
+ *	When the action is set to %IEEE80211_AMPDU_TX_OPERATIONAL the driver
  *	may neither send aggregates containing more subframes than this
  *	nor send aggregates in a way that lost frames would exceed the
  *	buffer size. If just limiting the aggregate size, this would be
diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 10ad4ac1fa0ba8ebd04e793595fab47d326194ce..78672737fe3eef1c3f93f6a394217f8aa1853739 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -323,7 +323,7 @@ void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 		__skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 
 	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
-			       &sta->sta, tid, &start_seq_num, 0, false);
+			       &sta->sta, tid, &start_seq_num, buf_size, false);
 	ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 	       sta->sta.addr, tid, ret);
 	if (ret) {