ath9k: add txq locking for ath_tx_aggr_start

Prevents race conditions when un-aggregated frames are pending in the
driver.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 9b3736ea2aafdd871707dd44e6724c1198e7a253..5ac713d2ff5d22dc6d976291c6d97098bfbceafd 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1390,11 +1390,15 @@ int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
                      u16 tid, u16 *ssn)
 {
        struct ath_atx_tid *txtid;
+       struct ath_txq *txq;
        struct ath_node *an;
        u8 density;
 
        an = (struct ath_node *)sta->drv_priv;
        txtid = ATH_AN_2_TID(an, tid);
+       txq = txtid->ac->txq;
+
+       ath_txq_lock(sc, txq);
 
        /* update ampdu factor/density, they may have changed. This may happen
         * in HT IBSS when a beacon with HT-info is received after the station
@@ -1418,6 +1422,8 @@ int ath_tx_aggr_start(struct ath_softc *sc, struct ieee80211_sta *sta,
        memset(txtid->tx_buf, 0, sizeof(txtid->tx_buf));
        txtid->baw_head = txtid->baw_tail = 0;
 
+       ath_txq_unlock_complete(sc, txq);
+
        return 0;
 }