ice: Sync VLAN filtering features for DVM

VLAN filtering features, that is C-Tag and S-Tag, in DVM mode must be
both enabled or disabled.
In case of turning off/on only one of the features, another feature must
be turned off/on automatically with issuing an appropriate message to
the kernel log.

Fixes: 1babaf7 ("ice: Advertise 802.1ad VLAN filtering and offloads for PF netdev")
Signed-off-by: Roman Storozhenko <roman.storozhenko@intel.com>
Co-developed-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Signed-off-by: Anatolii Gerasymenko <anatolii.gerasymenko@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

Author: rstorozh

drivers/net/ethernet/intel/ice/ice_main.c

@@ -5763,25 +5763,38 @@ static netdev_features_t
 ice_fix_features(struct net_device *netdev, netdev_features_t features)
 {
 	struct ice_netdev_priv *np = netdev_priv(netdev);
-	netdev_features_t supported_vlan_filtering;
-	netdev_features_t requested_vlan_filtering;
-	struct ice_vsi *vsi = np->vsi;
-
-	requested_vlan_filtering = features & NETIF_VLAN_FILTERING_FEATURES;
-
-	/* make sure supported_vlan_filtering works for both SVM and DVM */
-	supported_vlan_filtering = NETIF_F_HW_VLAN_CTAG_FILTER;
-	if (ice_is_dvm_ena(&vsi->back->hw))
-		supported_vlan_filtering |= NETIF_F_HW_VLAN_STAG_FILTER;
-
-	if (requested_vlan_filtering &&
-	    requested_vlan_filtering != supported_vlan_filtering) {
-		if (requested_vlan_filtering & NETIF_F_HW_VLAN_CTAG_FILTER) {
-			netdev_warn(netdev, "cannot support requested VLAN filtering settings, enabling all supported VLAN filtering settings\n");
-			features |= supported_vlan_filtering;
+	netdev_features_t req_vlan_fltr, cur_vlan_fltr;
+	bool cur_ctag, cur_stag, req_ctag, req_stag;
+
+	cur_vlan_fltr = netdev->features & NETIF_VLAN_FILTERING_FEATURES;
+	cur_ctag = cur_vlan_fltr & NETIF_F_HW_VLAN_CTAG_FILTER;
+	cur_stag = cur_vlan_fltr & NETIF_F_HW_VLAN_STAG_FILTER;
+
+	req_vlan_fltr = features & NETIF_VLAN_FILTERING_FEATURES;
+	req_ctag = req_vlan_fltr & NETIF_F_HW_VLAN_CTAG_FILTER;
+	req_stag = req_vlan_fltr & NETIF_F_HW_VLAN_STAG_FILTER;
+
+	if (req_vlan_fltr != cur_vlan_fltr) {
+		if (ice_is_dvm_ena(&np->vsi->back->hw)) {
+			if (req_ctag && req_stag) {
+				features |= NETIF_VLAN_FILTERING_FEATURES;
+			} else if (!req_ctag && !req_stag) {
+				features &= ~NETIF_VLAN_FILTERING_FEATURES;
+			} else if ((!cur_ctag && req_ctag && !cur_stag) ||
+				   (!cur_stag && req_stag && !cur_ctag)) {
+				features |= NETIF_VLAN_FILTERING_FEATURES;
+				netdev_warn(netdev,  "802.1Q and 802.1ad VLAN filtering must be either both on or both off. VLAN filtering has been enabled for both types.\n");
+			} else if ((cur_ctag && !req_ctag && cur_stag) ||
+				   (cur_stag && !req_stag && cur_ctag)) {
+				features &= ~NETIF_VLAN_FILTERING_FEATURES;
+				netdev_warn(netdev,  "802.1Q and 802.1ad VLAN filtering must be either both on or both off. VLAN filtering has been disabled for both types.\n");
+			}
 		} else {
-			netdev_warn(netdev, "cannot support requested VLAN filtering settings, clearing all supported VLAN filtering settings\n");
-			features &= ~supported_vlan_filtering;
+			if (req_vlan_fltr & NETIF_F_HW_VLAN_STAG_FILTER)
+				netdev_warn(netdev, "cannot support requested 802.1ad filtering setting in SVM mode\n");
+
+			if (req_vlan_fltr & NETIF_F_HW_VLAN_CTAG_FILTER)
+				features |= NETIF_F_HW_VLAN_CTAG_FILTER;
 		}
 	}