ath9k_hw: enable interrupts for beacon tx completion events

Not doing so could cause the tx status queue to overflow during longer
periods of time without non-beacon tx. These events are also required
for proper drv_tx_last_beacon handling.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -745,7 +745,11 @@ int ath9k_hw_beaconq_setup(struct ath_hw *ah)
 	qi.tqi_aifs = 1;
 	qi.tqi_cwmin = 0;
 	qi.tqi_cwmax = 0;
-	/* NB: don't enable any interrupts */
+
+	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
+		qi.tqi_qflags = TXQ_FLAG_TXOKINT_ENABLE |
+				TXQ_FLAG_TXERRINT_ENABLE;
+
 	return ath9k_hw_setuptxqueue(ah, ATH9K_TX_QUEUE_BEACON, &qi);
 }
 EXPORT_SYMBOL(ath9k_hw_beaconq_setup);