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>

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index e345ec8..73bb8ea 100644 (file)
--- 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);

diff --git a/include/linux/mv643xx_eth.h b/include/linux/mv643xx_eth.h
index cbbbe9b..30b0c4e 100644 (file)
--- a/include/linux/mv643xx_eth.h
+++ b/include/linux/mv643xx_eth.h
@@ -19,6 +19,11 @@ struct mv643xx_eth_shared_platform_data {
        struct mbus_dram_target_info    *dram;
        struct platform_device  *shared_smi;
        unsigned int            t_clk;
+       /*
+        * Max packet size for Tx IP/Layer 4 checksum, when set to 0, default
+        * limit of 9KiB will be used.
+        */
+       int                     tx_csum_limit;
 };
 
 #define MV643XX_ETH_PHY_ADDR_DEFAULT   0