xilinx_emacps: Fixes bug in skb handling for fragmented packets

The existing driver has a bug related to skb handling for fragmented
Tx packets. This patch fixes it.

Signed-off-by: Anirudha Sarangi <anirudh@xilinx.com>

diff --git a/drivers/net/ethernet/xilinx/xilinx_emacps.c b/drivers/net/ethernet/xilinx/xilinx_emacps.c
index 1d09eb807bbc71be89537ea3b215bf8897acbb53..1e157daa82073453456bc308c2778bc006945855 100644 (file)
--- a/drivers/net/ethernet/xilinx/xilinx_emacps.c
+++ b/drivers/net/ethernet/xilinx/xilinx_emacps.c
@@ -1273,6 +1273,7 @@ static void xemacps_tx_poll(unsigned long data)
        struct net_local *lp = netdev_priv(ndev);
        u32 regval;
        u32 len = 0;
+       u32 leninbd = 0;
        unsigned int bdcount = 0;
        unsigned int bdpartialcount = 0;
        unsigned int sop = 0;
@@ -1328,8 +1329,8 @@ static void xemacps_tx_poll(unsigned long data)
                rp = &lp->tx_skb[lp->tx_bd_ci];
                skb = rp->skb;
 
-               BUG_ON(skb == NULL);
-               len += skb->len;
+               leninbd = cur_p->ctrl & XEMACPS_TXBUF_LEN_MASK;
+               len += leninbd;
 
 #ifdef CONFIG_XILINX_PS_EMAC_HWTSTAMP
                if ((lp->hwtstamp_config.tx_type == HWTSTAMP_TX_ON) &&
@@ -1350,10 +1351,11 @@ static void xemacps_tx_poll(unsigned long data)
                }
 #endif /* CONFIG_XILINX_PS_EMAC_HWTSTAMP */
 
-               dma_unmap_single(&lp->pdev->dev, rp->mapping, skb->len,
+               dma_unmap_single(&lp->pdev->dev, rp->mapping, leninbd,
                        DMA_TO_DEVICE);
+               if (skb != NULL)
+                       dev_kfree_skb(skb);
                rp->skb = NULL;
-               dev_kfree_skb(skb);
                /* log tx completed packets and bytes, errors logs
                 * are in other error counters.
                 */
@@ -2054,9 +2056,11 @@ static int xemacps_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                        frag++;
                }
 
-               lp->tx_skb[lp->tx_bd_tail].skb = skb;
+               if (i == 0)
+                       lp->tx_skb[lp->tx_bd_tail].skb = skb;
+               else
+                       lp->tx_skb[lp->tx_bd_tail].skb = NULL;
                lp->tx_skb[lp->tx_bd_tail].mapping = mapping;
-
                cur_p->addr = mapping;
 
                /* Preserve only critical status bits.  Packet is NOT to be