ath9k: tx queue enable is read only for EDMA chipsets

for EDMA chip AR_Q_TXE (tx enable for each queue) is read only
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/beacon.c

@@ -356,6 +356,7 @@ void ath_beacon_tasklet(unsigned long data)
 	struct ath_buf *bf = NULL;
 	struct ieee80211_vif *vif;
 	struct ath_tx_status ts;
+	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
 	int slot;
 	u32 bfaddr, bc = 0;
 
@@ -456,10 +457,12 @@ void ath_beacon_tasklet(unsigned long data)
 	if (bfaddr != 0) {
 		/* NB: cabq traffic should already be queued and primed */
 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bfaddr);
-		ath9k_hw_txstart(ah, sc->beacon.beaconq);
+
+		if (!edma)
+			ath9k_hw_txstart(ah, sc->beacon.beaconq);
 
 		sc->beacon.ast_be_xmit += bc;     /* XXX per-vif? */
-		if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
+		if (edma) {
 			spin_lock_bh(&sc->sc_pcu_lock);
 			ath9k_hw_txprocdesc(ah, bf->bf_desc, (void *)&ts);
 			spin_unlock_bh(&sc->sc_pcu_lock);