ath9k: Pause other virtual wiphys on channel change

For now, allow channel changes immediately and just force the other
virtual wiphys to paused state. This is needed to allow
mac80211-controlled scan to control channel changes.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath9k/ath9k.h

@@ -710,5 +710,7 @@ int ath9k_wiphy_unpause(struct ath_wiphy *aphy);
 int ath9k_wiphy_select(struct ath_wiphy *aphy);
 void ath9k_wiphy_chan_work(struct work_struct *work);
 bool ath9k_wiphy_started(struct ath_softc *sc);
+void ath9k_wiphy_pause_all_forced(struct ath_softc *sc,
+				  struct ath_wiphy *selected);
 
 #endif /* ATH9K_H */

drivers/net/wireless/ath9k/main.c

@@ -2343,7 +2343,13 @@ static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
 		aphy->chan_is_ht = conf_is_ht(conf);
 
 		/* TODO: do not change operation channel immediately if there
-		 * are other virtual wiphys that use another channel */
+		 * are other virtual wiphys that use another channel. For now,
+		 * we do the change immediately to allow mac80211-operated scan
+		 * to work. Once the scan operation is moved into ath9k, we can
+		 * just move the current aphy in PAUSED state if the channel is
+		 * changed into something different from the current operation
+		 * channel. */
+		ath9k_wiphy_pause_all_forced(sc, aphy);
 
 		DPRINTF(sc, ATH_DBG_CONFIG, "Set channel: %d MHz\n",
 			curchan->center_freq);

drivers/net/wireless/ath9k/virtual.c

@@ -496,3 +496,27 @@ bool ath9k_wiphy_started(struct ath_softc *sc)
 	spin_unlock_bh(&sc->wiphy_lock);
 	return false;
 }
+
+static void ath9k_wiphy_pause_chan(struct ath_wiphy *aphy,
+				   struct ath_wiphy *selected)
+{
+	if (aphy->chan_idx == selected->chan_idx)
+		return;
+	aphy->state = ATH_WIPHY_PAUSED;
+	ieee80211_stop_queues(aphy->hw);
+}
+
+void ath9k_wiphy_pause_all_forced(struct ath_softc *sc,
+				  struct ath_wiphy *selected)
+{
+	int i;
+	spin_lock_bh(&sc->wiphy_lock);
+	if (sc->pri_wiphy->state == ATH_WIPHY_ACTIVE)
+		ath9k_wiphy_pause_chan(sc->pri_wiphy, selected);
+	for (i = 0; i < sc->num_sec_wiphy; i++) {
+		if (sc->sec_wiphy[i] &&
+		    sc->sec_wiphy[i]->state == ATH_WIPHY_ACTIVE)
+			ath9k_wiphy_pause_chan(sc->sec_wiphy[i], selected);
+	}
+	spin_unlock_bh(&sc->wiphy_lock);
+}