--- /dev/null
+--- a/drivers/net/wireless/ath/ath9k/init.c
++++ b/drivers/net/wireless/ath/ath9k/init.c
+@@ -667,8 +667,10 @@ static void ath9k_init_band_txpower(stru
+ static void ath9k_init_txpower_limits(struct ath_softc *sc)
+ {
+ struct ath_hw *ah = sc->sc_ah;
++ struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+ struct ath9k_channel *curchan = ah->curchan;
+
++ ah->txchainmask = common->tx_chainmask;
+ if (ah->caps.hw_caps & ATH9K_HW_CAP_2GHZ)
+ ath9k_init_band_txpower(sc, IEEE80211_BAND_2GHZ);
+ if (ah->caps.hw_caps & ATH9K_HW_CAP_5GHZ)