be2net: workaround to fix a bug in BE

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>

1 files changed, 38 insertions, 8 deletions

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index 73fe38928c2b..62f55145fa44 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -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;
 }