mv643xx_eth: use sw csum for big packets

Some controllers (KW, Dove) limits the TX IP/layer4 checksum offloading to a max size.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Acked-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index e345ec8cb473..73bb8ea6f54a 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -289,6 +289,7 @@ struct mv643xx_eth_shared_private {
         unsigned int t_clk;
         int extended_rx_coal_limit;
         int tx_bw_control;
+        int tx_csum_limit;
 };
 
 #define TX_BW_CONTROL_ABSENT            0
@@ -776,13 +777,16 @@ static int txq_submit_skb(struct tx_queue *txq, struct sk_buff *skb)
         l4i_chk = 0;
 
         if (skb->ip_summed == CHECKSUM_PARTIAL) {
+                int hdr_len;
                 int tag_bytes;
 
                 BUG_ON(skb->protocol != htons(ETH_P_IP) &&
                        skb->protocol != htons(ETH_P_8021Q));
 
-                tag_bytes = (void *)ip_hdr(skb) - (void *)skb->data - ETH_HLEN;
-                if (unlikely(tag_bytes & ~12)) {
+                hdr_len = (void *)ip_hdr(skb) - (void *)skb->data;
+                tag_bytes = hdr_len - ETH_HLEN;
+                if (skb->len - hdr_len > mp->shared->tx_csum_limit ||
+                    unlikely(tag_bytes & ~12)) {
                         if (skb_checksum_help(skb) == 0)
                                 goto no_csum;
                         kfree_skb(skb);
@@ -2666,6 +2670,7 @@ static int mv643xx_eth_shared_probe(struct platform_device *pdev)
          * Detect hardware parameters.
          */
         msp->t_clk = (pd != NULL && pd->t_clk != 0) ? pd->t_clk : 133000000;
+        msp->tx_csum_limit = pd->tx_csum_limit ? pd->tx_csum_limit : 9 * 1024;
         infer_hw_params(msp);
 
         platform_set_drvdata(pdev, msp);