ath9k: Fix HW scan abort

Instead of using ATH_CHANCTX_EVENT_ASSIGN to abort
a HW scan when a new interface becomes active, use the
mgd_prepare_tx() callback. This allows us to make
sure that the GO's channel becomes operational by
using flush_work().
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -743,22 +743,6 @@ void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
 		ieee80211_queue_work(sc->hw, &sc->chanctx_work);
 		break;
 	case ATH_CHANCTX_EVENT_ASSIGN:
-		/*
-		 * When adding a new channel context, check if a scan
-		 * is in progress and abort it since the addition of
-		 * a new channel context is usually followed by VIF
-		 * assignment, in which case we have to start multi-channel
-		 * operation.
-		 */
-		if (test_bit(ATH_OP_SCANNING, &common->op_flags)) {
-			ath_dbg(common, CHAN_CTX,
-				"Aborting HW scan to add new context\n");
-
-			spin_unlock_bh(&sc->chan_lock);
-			del_timer_sync(&sc->offchannel.timer);
-			ath_scan_complete(sc, true);
-			spin_lock_bh(&sc->chan_lock);
-		}
 		break;
 	case ATH_CHANCTX_EVENT_CHANGE:
 		break;

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

@@ -2365,7 +2365,6 @@ static int ath9k_add_chanctx(struct ieee80211_hw *hw,
 			conf->def.chan->center_freq);
 
 		ath_chanctx_set_channel(sc, ctx, &conf->def);
-		ath_chanctx_event(sc, NULL, ATH_CHANCTX_EVENT_ASSIGN);
 
 		mutex_unlock(&sc->mutex);
 		return 0;
@@ -2496,6 +2495,19 @@ static void ath9k_mgd_prepare_tx(struct ieee80211_hw *hw,
 	if (!changed)
 		goto out;
 
+	if (test_bit(ATH_OP_SCANNING, &common->op_flags)) {
+		ath_dbg(common, CHAN_CTX,
+			"%s: Aborting HW scan\n", __func__);
+
+		mutex_unlock(&sc->mutex);
+
+		del_timer_sync(&sc->offchannel.timer);
+		ath_scan_complete(sc, true);
+		flush_work(&sc->chanctx_work);
+
+		mutex_lock(&sc->mutex);
+	}
+
 	go_ctx = ath_is_go_chanctx_present(sc);
 
 	if (go_ctx) {