ath9k: Cleanup add/change_interface callbacks

*Remove all the checks that will be handled by cfg80211
based on the interface combination advertised. For instance,
driver supports at the maximum 8 beaconing interface, while
we advertise maximum 8 beaconing interface in the interface
combination support.

*cfg80211 will take care of not allowing
us to add an interface that is not supported by the
driver, further if the change_interface changes the
old interface to a beaconing interface while we had
reached the max limit of 8 beaconing interface, again
cfg80211 takes care of this stuff!
So remove all these checks.

*Beautify placing PS wrappers in the appropriate
position.

Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -986,47 +986,21 @@ static int ath9k_add_interface(struct ieee80211_hw *hw,
 	struct ath_softc *sc = hw->priv;
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
-	int ret = 0;
 
-	ath9k_ps_wakeup(sc);
 	mutex_lock(&sc->mutex);
 
-	switch (vif->type) {
-	case NL80211_IFTYPE_STATION:
-	case NL80211_IFTYPE_WDS:
-	case NL80211_IFTYPE_ADHOC:
-	case NL80211_IFTYPE_AP:
-	case NL80211_IFTYPE_MESH_POINT:
-		break;
-	default:
-		ath_err(common, "Interface type %d not yet supported\n",
-			vif->type);
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-
-	if (ath9k_uses_beacons(vif->type)) {
-		if (sc->nbcnvifs >= ATH_BCBUF) {
-			ath_err(common, "Not enough beacon buffers when adding"
-				" new interface of type: %i\n",
-				vif->type);
-			ret = -ENOBUFS;
-			goto out;
-		}
-	}
-
 	ath_dbg(common, CONFIG, "Attach a VIF of type: %d\n", vif->type);
-
 	sc->nvifs++;
 
+	ath9k_ps_wakeup(sc);
 	ath9k_calculate_summary_state(hw, vif);
+	ath9k_ps_restore(sc);
+
 	if (ath9k_uses_beacons(vif->type))
 		ath9k_beacon_assign_slot(sc, vif);
 
-out:
 	mutex_unlock(&sc->mutex);
-	ath9k_ps_restore(sc);
-	return ret;
+	return 0;
 }
 
 static int ath9k_change_interface(struct ieee80211_hw *hw,
@@ -1036,21 +1010,9 @@ static int ath9k_change_interface(struct ieee80211_hw *hw,
 {
 	struct ath_softc *sc = hw->priv;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
-	int ret = 0;
 
 	ath_dbg(common, CONFIG, "Change Interface\n");
-
 	mutex_lock(&sc->mutex);
-	ath9k_ps_wakeup(sc);
-
-	if (ath9k_uses_beacons(new_type) &&
-	    !ath9k_uses_beacons(vif->type)) {
-		if (sc->nbcnvifs >= ATH_BCBUF) {
-			ath_err(common, "No beacon slot available\n");
-			ret = -ENOBUFS;
-			goto out;
-		}
-	}
 
 	if (ath9k_uses_beacons(vif->type))
 		ath9k_beacon_remove_slot(sc, vif);
@@ -1058,14 +1020,15 @@ static int ath9k_change_interface(struct ieee80211_hw *hw,
 	vif->type = new_type;
 	vif->p2p = p2p;
 
+	ath9k_ps_wakeup(sc);
 	ath9k_calculate_summary_state(hw, vif);
+	ath9k_ps_restore(sc);
+
 	if (ath9k_uses_beacons(vif->type))
 		ath9k_beacon_assign_slot(sc, vif);
 
-out:
-	ath9k_ps_restore(sc);
 	mutex_unlock(&sc->mutex);
-	return ret;
+	return 0;
 }
 
 static void ath9k_remove_interface(struct ieee80211_hw *hw,
@@ -1076,7 +1039,6 @@ static void ath9k_remove_interface(struct ieee80211_hw *hw,
 
 	ath_dbg(common, CONFIG, "Detach Interface\n");
 
-	ath9k_ps_wakeup(sc);
 	mutex_lock(&sc->mutex);
 
 	sc->nvifs--;
@@ -1084,10 +1046,11 @@ static void ath9k_remove_interface(struct ieee80211_hw *hw,
 	if (ath9k_uses_beacons(vif->type))
 		ath9k_beacon_remove_slot(sc, vif);
 
+	ath9k_ps_wakeup(sc);
 	ath9k_calculate_summary_state(hw, NULL);
+	ath9k_ps_restore(sc);
 
 	mutex_unlock(&sc->mutex);
-	ath9k_ps_restore(sc);
 }
 
 static void ath9k_enable_ps(struct ath_softc *sc)