ath9k: Fix beacon configuration for channel contexts

In channel context mode, when a new context is added,
mac80211 issues a bss_info_changed() notfication when
preparing the connection for the new interface/context.

But, this is done prior to the mgd_prepare_tx() call which
is where we switch to the new context. Since the current
context will be different when the earlier bss_info_changed()
is handled, the beacon information for the VIF is not
updated, but discarded since the rules for the current context
disallows it.

In the subsequent association process for the new context/vif,
this becomes a problem because the beacon parameters are invalid.
This causes problems with the TSF timer, causing large jumps.

To fix this, check if the beacon info is being updated for a
different context and if so, allow it without any checks since
we limit the max. interfaces to two anyway.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -514,6 +514,18 @@ static bool ath9k_allow_beacon_config(struct ath_softc *sc,
 				      struct ieee80211_vif *vif)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ath_vif *avp = (void *)vif->drv_priv;
+
+	if (ath9k_is_chanctx_enabled()) {
+		/*
+		 * If the VIF is not present in the current channel context,
+		 * then we can't do the usual opmode checks. Allow the
+		 * beacon config for the VIF to be updated in this case and
+		 * return immediately.
+		 */
+		if (sc->cur_chan != avp->chanctx)
+			return true;
+	}
 
 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
 		if ((vif->type != NL80211_IFTYPE_AP) ||