ath9k: prepare for multi-interface CSA support

Soon mac80211 will support multi-interface CSA so
using sc->csa_vif is not an option.

Instead just depend on vif->csa_active. Calling
ieee80211_csa_finish() multiple number of times
should not be an issue.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -442,7 +442,8 @@ void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
 void ath9k_beacon_assign_slot(struct ath_softc *sc, struct ieee80211_vif *vif);
 void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif);
 void ath9k_set_beacon(struct ath_softc *sc);
-bool ath9k_csa_is_finished(struct ath_softc *sc);
+bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif);
+void ath9k_csa_update(struct ath_softc *sc);
 
 /*******************/
 /* Link Monitoring */
@@ -774,7 +775,6 @@ struct ath_softc {
 #endif
 
 	struct ath_descdma txsdma;
-	struct ieee80211_vif *csa_vif;
 
 	struct ath_ant_comb ant_comb;
 	u8 ant_tx, ant_rx;

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

@@ -292,11 +292,8 @@ static void ath9k_set_tsfadjust(struct ath_softc *sc, struct ieee80211_vif *vif)
 		(unsigned long long)tsfadjust, avp->av_bslot);
 }
 
-bool ath9k_csa_is_finished(struct ath_softc *sc)
+bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif)
 {
-	struct ieee80211_vif *vif;
-
-	vif = sc->csa_vif;
 	if (!vif || !vif->csa_active)
 		return false;
 
@@ -304,11 +301,23 @@ bool ath9k_csa_is_finished(struct ath_softc *sc)
 		return false;
 
 	ieee80211_csa_finish(vif);
-
-	sc->csa_vif = NULL;
 	return true;
 }
 
+static void ath9k_csa_update_vif(void *data, u8 *mac, struct ieee80211_vif *vif)
+{
+	struct ath_softc *sc = data;
+	ath9k_csa_is_finished(sc, vif);
+}
+
+void ath9k_csa_update(struct ath_softc *sc)
+{
+	ieee80211_iterate_active_interfaces(sc->hw,
+					    IEEE80211_IFACE_ITER_NORMAL,
+					    ath9k_csa_update_vif,
+					    sc);
+}
+
 void ath9k_beacon_tasklet(unsigned long data)
 {
 	struct ath_softc *sc = (struct ath_softc *)data;
@@ -362,13 +371,13 @@ void ath9k_beacon_tasklet(unsigned long data)
 		return;
 	}
 
-	/* EDMA devices check that in the tx completion function. */
-	if (!edma && ath9k_csa_is_finished(sc))
-		return;
-
 	slot = ath9k_beacon_choose_slot(sc);
 	vif = sc->beacon.bslot[slot];
 
+	/* EDMA devices check that in the tx completion function. */
+	if (!edma && ath9k_csa_is_finished(sc, vif))
+		return;
+
 	if (!vif || !vif->bss_conf.enable_beacon)
 		return;
 

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

@@ -1178,9 +1178,6 @@ static void ath9k_remove_interface(struct ieee80211_hw *hw,
 	if (ath9k_uses_beacons(vif->type))
 		ath9k_beacon_remove_slot(sc, vif);
 
-	if (sc->csa_vif == vif)
-		sc->csa_vif = NULL;
-
 	ath9k_ps_wakeup(sc);
 	ath9k_calculate_summary_state(hw, NULL);
 	ath9k_ps_restore(sc);
@@ -2086,13 +2083,8 @@ static void ath9k_channel_switch_beacon(struct ieee80211_hw *hw,
 					struct ieee80211_vif *vif,
 					struct cfg80211_chan_def *chandef)
 {
-	struct ath_softc *sc = hw->priv;
-
-	/* mac80211 does not support CSA in multi-if cases (yet) */
-	if (WARN_ON(sc->csa_vif))
-		return;
-
-	sc->csa_vif = vif;
+	/* depend on vif->csa_active only */
+	return;
 }
 
 struct ieee80211_ops ath9k_ops = {

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

@@ -2566,7 +2566,7 @@ void ath_tx_edma_tasklet(struct ath_softc *sc)
 			sc->beacon.tx_processed = true;
 			sc->beacon.tx_last = !(ts.ts_status & ATH9K_TXERR_MASK);
 
-			ath9k_csa_is_finished(sc);
+			ath9k_csa_update(sc);
 			continue;
 		}