mwifiex: Small cleanup for handling virtual interface type changes

Handle the obvious invalid virtual interface type changes with a general
check instead of looking at the individual change.

For type changes from P2P_CLIENT to P2P_GO and the other way round, this
changes the behavior slightly: We now still do nothing, but return
-EOPNOTSUPP instead of 0. Now that behavior was incorrect before and
still is, because type changes between these two types are actually
possible and supported, which we'll fix in a following commit.
Signed-off-by: Jonas Dreßler <verdre@v0yd.nl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210914195909.36035-2-verdre@v0yd.nl

drivers/net/wireless/marvell/mwifiex/cfg80211.c

@@ -1141,6 +1141,20 @@ mwifiex_cfg80211_change_virtual_intf(struct wiphy *wiphy,
 		return -EBUSY;
 	}
 
+	if (type == NL80211_IFTYPE_UNSPECIFIED) {
+		mwifiex_dbg(priv->adapter, INFO,
+			    "%s: no new type specified, keeping old type %d\n",
+			    dev->name, curr_iftype);
+		return 0;
+	}
+
+	if (curr_iftype == type) {
+		mwifiex_dbg(priv->adapter, INFO,
+			    "%s: interface already is of type %d\n",
+			    dev->name, curr_iftype);
+		return 0;
+	}
+
 	switch (curr_iftype) {
 	case NL80211_IFTYPE_ADHOC:
 		switch (type) {
@@ -1160,12 +1174,6 @@ mwifiex_cfg80211_change_virtual_intf(struct wiphy *wiphy,
 		case NL80211_IFTYPE_AP:
 			return mwifiex_change_vif_to_ap(dev, curr_iftype, type,
 							params);
-		case NL80211_IFTYPE_UNSPECIFIED:
-			mwifiex_dbg(priv->adapter, INFO,
-				    "%s: kept type as IBSS\n", dev->name);
-			fallthrough;
-		case NL80211_IFTYPE_ADHOC:	/* This shouldn't happen */
-			return 0;
 		default:
 			mwifiex_dbg(priv->adapter, ERROR,
 				    "%s: changing to %d not supported\n",
@@ -1191,12 +1199,6 @@ mwifiex_cfg80211_change_virtual_intf(struct wiphy *wiphy,
 		case NL80211_IFTYPE_AP:
 			return mwifiex_change_vif_to_ap(dev, curr_iftype, type,
 							params);
-		case NL80211_IFTYPE_UNSPECIFIED:
-			mwifiex_dbg(priv->adapter, INFO,
-				    "%s: kept type as STA\n", dev->name);
-			fallthrough;
-		case NL80211_IFTYPE_STATION:	/* This shouldn't happen */
-			return 0;
 		default:
 			mwifiex_dbg(priv->adapter, ERROR,
 				    "%s: changing to %d not supported\n",
@@ -1214,12 +1216,6 @@ mwifiex_cfg80211_change_virtual_intf(struct wiphy *wiphy,
 		case NL80211_IFTYPE_P2P_GO:
 			return mwifiex_change_vif_to_p2p(dev, curr_iftype,
 							 type, params);
-		case NL80211_IFTYPE_UNSPECIFIED:
-			mwifiex_dbg(priv->adapter, INFO,
-				    "%s: kept type as AP\n", dev->name);
-			fallthrough;
-		case NL80211_IFTYPE_AP:		/* This shouldn't happen */
-			return 0;
 		default:
 			mwifiex_dbg(priv->adapter, ERROR,
 				    "%s: changing to %d not supported\n",
@@ -1254,13 +1250,6 @@ mwifiex_cfg80211_change_virtual_intf(struct wiphy *wiphy,
 				return -EFAULT;
 			return mwifiex_change_vif_to_ap(dev, curr_iftype, type,
 							params);
-		case NL80211_IFTYPE_UNSPECIFIED:
-			mwifiex_dbg(priv->adapter, INFO,
-				    "%s: kept type as P2P\n", dev->name);
-			fallthrough;
-		case NL80211_IFTYPE_P2P_CLIENT:
-		case NL80211_IFTYPE_P2P_GO:
-			return 0;
 		default:
 			mwifiex_dbg(priv->adapter, ERROR,
 				    "%s: changing to %d not supported\n",