ath9k: Fix flushing in MCC mode

When we are attempting to switch to a new
channel context, the TX queues are flushed, but
the mac80211 queues are not stopped and traffic
can still come down to the driver.

This patch fixes it by stopping the queues
assigned to the current context/vif before
trying to flush.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/channel.c b/drivers/net/wireless/ath/ath9k/channel.c
index bf5ecd8..945c898 100644
--- a/drivers/net/wireless/ath/ath9k/channel.c
+++ b/drivers/net/wireless/ath/ath9k/channel.c
@@ -1044,9 +1044,11 @@
 void ath_chanctx_set_next(struct ath_softc *sc, bool force)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ath_chanctx *old_ctx;
 	struct timespec ts;
 	bool measure_time = false;
 	bool send_ps = false;
+	bool queues_stopped = false;
 
 	spin_lock_bh(&sc->chan_lock);
 	if (!sc->next_chan) {
@@ -1076,6 +1078,10 @@
 			getrawmonotonic(&ts);
 			measure_time = true;
 		}
+
+		ath9k_chanctx_stop_queues(sc, sc->cur_chan);
+		queues_stopped = true;
+
 		__ath9k_flush(sc->hw, ~0, true);
 
 		if (ath_chanctx_send_ps_frame(sc, true))
@@ -1089,6 +1095,7 @@
 			sc->cur_chan->tsf_val = ath9k_hw_gettsf64(sc->sc_ah);
 		}
 	}
+	old_ctx = sc->cur_chan;
 	sc->cur_chan = sc->next_chan;
 	sc->cur_chan->stopped = false;
 	sc->next_chan = NULL;
@@ -1111,7 +1118,16 @@
 		if (measure_time)
 			sc->sched.channel_switch_time =
 				ath9k_hw_get_tsf_offset(&ts, NULL);
+		/*
+		 * A reset will ensure that all queues are woken up,
+		 * so there is no need to awaken them again.
+		 */
+		goto out;
 	}
+
+	if (queues_stopped)
+		ath9k_chanctx_wake_queues(sc, old_ctx);
+out:
 	if (send_ps)
 		ath_chanctx_send_ps_frame(sc, false);