ath9k: Fix beacon configuration for addition/removal of interfaces

This patch fixes some issues with interface reconfiguration. It could
for example happen that an AP interface in beacon slot 0 was removed
leaving an IBSS station in one of the other slots. When this happens
the driver never sends out the beacon as it only tries to send a beacon
from slot 0.

Appart from that the tracking of required changes to the beacon config is
relatively complicated and prone to errors.

The approach taken here is to solve reconfiguration issues is to
reconfigure the beacons when any interface changes. This means that
the complexity of deciding whether an interface change may modify the
beacon configuration is gone. It also means that the beacon config will
be reliably updated when an interface is removed.

The issue that a single non-AP interface might not be in beacon
slot 0 and wouldn't be send out is solved by moving it into the
first slot. The TSF value in hardware is adjusted accordingly so
that the timestamp of the beacons stay consistent.

Signed-off-by: Benjamin Berg <benjamin.berg@open-mesh.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 26 insertions, 17 deletions

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 820df45ef33d..7594650f214f 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -910,6 +910,22 @@ static bool ath9k_uses_beacons(int type)
 	}
 }
 
+static void ath9k_vif_iter_set_beacon(struct ath9k_vif_iter_data *iter_data,
+				      struct ieee80211_vif *vif)
+{
+	/* Use the first (configured) interface, but prefering AP interfaces. */
+	if (!iter_data->primary_beacon_vif) {
+		iter_data->primary_beacon_vif = vif;
+	} else {
+		if (iter_data->primary_beacon_vif->type != NL80211_IFTYPE_AP &&
+		    vif->type == NL80211_IFTYPE_AP)
+		iter_data->primary_beacon_vif = vif;
+	}
+
+	iter_data->beacons = true;
+	iter_data->nbcnvifs += 1;
+}
+
 static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 			   u8 *mac, struct ieee80211_vif *vif)
 {
@@ -931,6 +947,8 @@ static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 	switch (vif->type) {
 	case NL80211_IFTYPE_AP:
 		iter_data->naps++;
+		if (vif->bss_conf.enable_beacon)
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_STATION:
 		iter_data->nstations++;
@@ -943,12 +961,12 @@ static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 	case NL80211_IFTYPE_ADHOC:
 		iter_data->nadhocs++;
 		if (vif->bss_conf.enable_beacon)
-			iter_data->beacons = true;
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_MESH_POINT:
 		iter_data->nmeshes++;
 		if (vif->bss_conf.enable_beacon)
-			iter_data->beacons = true;
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_WDS:
 		iter_data->nwds++;
@@ -1081,7 +1099,6 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath9k_vif_iter_data iter_data;
-	struct ath_beacon_config *cur_conf;
 
 	ath_chanctx_check_active(sc, ctx);
 
@@ -1103,13 +1120,12 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 	ath_hw_setbssidmask(common);
 
 	if (iter_data.naps > 0) {
-		cur_conf = &ctx->beacon;
 		ath9k_hw_set_tsfadjust(ah, true);
 		ah->opmode = NL80211_IFTYPE_AP;
-		if (cur_conf->enable_beacon)
-			iter_data.beacons = true;
 	} else {
 		ath9k_hw_set_tsfadjust(ah, false);
+		if (iter_data.beacons)
+			ath9k_beacon_ensure_primary_slot(sc);
 
 		if (iter_data.nmeshes)
 			ah->opmode = NL80211_IFTYPE_MESH_POINT;
@@ -1134,7 +1150,6 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 			ctx->switch_after_beacon = true;
 	}
 
-	ah->imask &= ~ATH9K_INT_SWBA;
 	if (ah->opmode == NL80211_IFTYPE_STATION) {
 		bool changed = (iter_data.primary_sta != ctx->primary_sta);
 
@@ -1151,16 +1166,12 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 			if (ath9k_hw_mci_is_enabled(sc->sc_ah))
 				ath9k_mci_update_wlan_channels(sc, true);
 		}
-	} else if (iter_data.beacons) {
-		ah->imask |= ATH9K_INT_SWBA;
 	}
+	sc->nbcnvifs = iter_data.nbcnvifs;
+	ath9k_beacon_config(sc, iter_data.primary_beacon_vif,
+			    iter_data.beacons);
 	ath9k_hw_set_interrupts(ah);
 
-	if (iter_data.beacons)
-		set_bit(ATH_OP_BEACONS, &common->op_flags);
-	else
-		clear_bit(ATH_OP_BEACONS, &common->op_flags);
-
 	if (ah->slottime != iter_data.slottime) {
 		ah->slottime = iter_data.slottime;
 		ath9k_hw_init_global_settings(ah);
@@ -1777,9 +1788,7 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
 	if ((changed & BSS_CHANGED_BEACON_ENABLED) ||
 	    (changed & BSS_CHANGED_BEACON_INT) ||
 	    (changed & BSS_CHANGED_BEACON_INFO)) {
-		ath9k_beacon_config(sc, vif, changed);
-		if (changed & BSS_CHANGED_BEACON_ENABLED)
-			ath9k_calculate_summary_state(sc, avp->chanctx);
+		ath9k_calculate_summary_state(sc, avp->chanctx);
 	}
 
 	if ((avp->chanctx == sc->cur_chan) &&