be2net: fix to limit max vlans supported in certain skews

In certain skews the ASIC can support only 16 vlans per interface.
Once the limit is crossed, the ASIC is programmed in vlan promiscuous mode.
Switch off the vlan promiscuous mode once the number of vlans
falls back to the max vlans supported.
Signed-off-by: Ajit Khaparde <ajitk@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/benet/be.h

@@ -250,7 +250,8 @@ struct be_adapter {
 	bool rx_post_starved;	/* Zero rx frags have been posted to BE */
 
 	struct vlan_group *vlan_grp;
-	u16 num_vlans;
+	u16 vlans_added;
+	u16 max_vlans;	/* Number of vlans supported */
 	u8 vlan_tag[VLAN_GROUP_ARRAY_LEN];
 	struct be_dma_mem mc_cmd_mem;
 

drivers/net/benet/be_main.c

@@ -488,17 +488,16 @@ static int be_change_mtu(struct net_device *netdev, int new_mtu)
 }
 
 /*
- * if there are BE_NUM_VLANS_SUPPORTED or lesser number of VLANS configured,
- * program them in BE.  If more than BE_NUM_VLANS_SUPPORTED are configured,
- * set the BE in promiscuous VLAN mode.
+ * A max of 64 (BE_NUM_VLANS_SUPPORTED) vlans can be configured in BE.
+ * If the user configures more, place BE in vlan promiscuous mode.
  */
 static int be_vid_config(struct be_adapter *adapter)
 {
 	u16 vtag[BE_NUM_VLANS_SUPPORTED];
 	u16 ntags = 0, i;
-	int status;
+	int status = 0;
 
-	if (adapter->num_vlans <= BE_NUM_VLANS_SUPPORTED)  {
+	if (adapter->vlans_added <= adapter->max_vlans)  {
 		/* Construct VLAN Table to give to HW */
 		for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
 			if (adapter->vlan_tag[i]) {
@@ -532,9 +531,9 @@ static void be_vlan_add_vid(struct net_device *netdev, u16 vid)
 {
 	struct be_adapter *adapter = netdev_priv(netdev);
 
-	adapter->num_vlans++;
 	adapter->vlan_tag[vid] = 1;
-
+	adapter->vlans_added++;
+	if (adapter->vlans_added <= (adapter->max_vlans + 1))
 		be_vid_config(adapter);
 }
 
@@ -542,10 +541,10 @@ static void be_vlan_rem_vid(struct net_device *netdev, u16 vid)
 {
 	struct be_adapter *adapter = netdev_priv(netdev);
 
-	adapter->num_vlans--;
 	adapter->vlan_tag[vid] = 0;
-
 	vlan_group_set_device(adapter->vlan_grp, vid, NULL);
+	adapter->vlans_added--;
+	if (adapter->vlans_added <= adapter->max_vlans)
 		be_vid_config(adapter);
 }
 
@@ -786,7 +785,7 @@ static void be_rx_compl_process(struct be_adapter *adapter,
 	skb->dev = adapter->netdev;
 
 	if (vlanf) {
-		if (!adapter->vlan_grp || adapter->num_vlans == 0) {
+		if (!adapter->vlan_grp || adapter->vlans_added == 0) {
 			kfree_skb(skb);
 			return;
 		}
@@ -866,7 +865,7 @@ static void be_rx_compl_process_gro(struct be_adapter *adapter,
 		vid = AMAP_GET_BITS(struct amap_eth_rx_compl, vlan_tag, rxcp);
 		vid = be16_to_cpu(vid);
 
-		if (!adapter->vlan_grp || adapter->num_vlans == 0)
+		if (!adapter->vlan_grp || adapter->vlans_added == 0)
 			return;
 
 		vlan_gro_frags(&eq_obj->napi, adapter->vlan_grp, vid);
@@ -2241,6 +2240,11 @@ static int be_get_config(struct be_adapter *adapter)
 	memcpy(adapter->netdev->dev_addr, mac, ETH_ALEN);
 	memcpy(adapter->netdev->perm_addr, mac, ETH_ALEN);
 
+	if (adapter->cap & 0x400)
+		adapter->max_vlans = BE_NUM_VLANS_SUPPORTED/4;
+	else
+		adapter->max_vlans = BE_NUM_VLANS_SUPPORTED;
+
 	return 0;
 }