be2net: workaround to fix a bug in BE
authorAjit Khaparde <ajit.khaparde@emulex.com>
Fri, 9 Dec 2011 13:53:17 +0000 (13:53 +0000)
committerDavid S. Miller <davem@davemloft.net>
Sun, 11 Dec 2011 23:25:15 +0000 (18:25 -0500)
disable Tx vlan offloading in certain cases.

Signed-off-by: Ajit Khaparde <ajit.khaparde@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/emulex/benet/be_main.c

index 73fe38928c2ba3e3c546c85503df582239cad87f..62f55145fa446cbf9b12fbcf26ae00558988279b 100644 (file)
@@ -552,11 +552,26 @@ static inline void wrb_fill(struct be_eth_wrb *wrb, u64 addr, int len)
        wrb->frag_len = len & ETH_WRB_FRAG_LEN_MASK;
 }
 
+static inline u16 be_get_tx_vlan_tag(struct be_adapter *adapter,
+                                       struct sk_buff *skb)
+{
+       u8 vlan_prio;
+       u16 vlan_tag;
+
+       vlan_tag = vlan_tx_tag_get(skb);
+       vlan_prio = (vlan_tag & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
+       /* If vlan priority provided by OS is NOT in available bmap */
+       if (!(adapter->vlan_prio_bmap & (1 << vlan_prio)))
+               vlan_tag = (vlan_tag & ~VLAN_PRIO_MASK) |
+                               adapter->recommended_prio;
+
+       return vlan_tag;
+}
+
 static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
                struct sk_buff *skb, u32 wrb_cnt, u32 len)
 {
-       u8 vlan_prio = 0;
-       u16 vlan_tag = 0;
+       u16 vlan_tag;
 
        memset(hdr, 0, sizeof(*hdr));
 
@@ -587,12 +602,7 @@ static void wrb_fill_hdr(struct be_adapter *adapter, struct be_eth_hdr_wrb *hdr,
 
        if (vlan_tx_tag_present(skb)) {
                AMAP_SET_BITS(struct amap_eth_hdr_wrb, vlan, hdr, 1);
-               vlan_tag = vlan_tx_tag_get(skb);
-               vlan_prio = (vlan_tag & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
-               /* If vlan priority provided by OS is NOT in available bmap */
-               if (!(adapter->vlan_prio_bmap & (1 << vlan_prio)))
-                       vlan_tag = (vlan_tag & ~VLAN_PRIO_MASK) |
-                                       adapter->recommended_prio;
+               vlan_tag = be_get_tx_vlan_tag(adapter, skb);
                AMAP_SET_BITS(struct amap_eth_hdr_wrb, vlan_tag, hdr, vlan_tag);
        }
 
@@ -695,6 +705,25 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
        u32 start = txq->head;
        bool dummy_wrb, stopped = false;
 
+       /* For vlan tagged pkts, BE
+        * 1) calculates checksum even when CSO is not requested
+        * 2) calculates checksum wrongly for padded pkt less than
+        * 60 bytes long.
+        * As a workaround disable TX vlan offloading in such cases.
+        */
+       if (unlikely(vlan_tx_tag_present(skb) &&
+                    (skb->ip_summed != CHECKSUM_PARTIAL || skb->len <= 60))) {
+               skb = skb_share_check(skb, GFP_ATOMIC);
+               if (unlikely(!skb))
+                       goto tx_drop;
+
+               skb = __vlan_put_tag(skb, be_get_tx_vlan_tag(adapter, skb));
+               if (unlikely(!skb))
+                       goto tx_drop;
+
+               skb->vlan_tci = 0;
+       }
+
        wrb_cnt = wrb_cnt_for_skb(adapter, skb, &dummy_wrb);
 
        copied = make_tx_wrbs(adapter, txq, skb, wrb_cnt, dummy_wrb);
@@ -722,6 +751,7 @@ static netdev_tx_t be_xmit(struct sk_buff *skb,
                txq->head = start;
                dev_kfree_skb_any(skb);
        }
+tx_drop:
        return NETDEV_TX_OK;
 }