net: lpc_eth: free skbs in start_xmit

Transmitted skbs can be freed immediately in lpc_eth_hard_start_xmit()
instead of at TX completion, since driver copies the frames in DMA area.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 6 deletions

diff --git a/drivers/net/ethernet/nxp/lpc_eth.c b/drivers/net/ethernet/nxp/lpc_eth.c
index 083d6715335c..028dde4d4979 100644
--- a/drivers/net/ethernet/nxp/lpc_eth.c
+++ b/drivers/net/ethernet/nxp/lpc_eth.c
@@ -440,7 +440,7 @@ struct netdata_local {
         spinlock_t              lock;
         void __iomem            *net_base;
         u32                     msg_enable;
-        struct sk_buff          *skb[ENET_TX_DESC];
+        unsigned int            skblen[ENET_TX_DESC];
         unsigned int            last_tx_idx;
         unsigned int            num_used_tx_buffs;
         struct mii_bus          *mii_bus;
@@ -903,12 +903,11 @@ err_out:
 static void __lpc_handle_xmit(struct net_device *ndev)
 {
         struct netdata_local *pldat = netdev_priv(ndev);
-        struct sk_buff *skb;
         u32 txcidx, *ptxstat, txstat;
 
         txcidx = readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
         while (pldat->last_tx_idx != txcidx) {
-                skb = pldat->skb[pldat->last_tx_idx];
+                unsigned int skblen = pldat->skblen[pldat->last_tx_idx];
 
                 /* A buffer is available, get buffer status */
                 ptxstat = &pldat->tx_stat_v[pldat->last_tx_idx];
@@ -945,9 +944,8 @@ static void __lpc_handle_xmit(struct net_device *ndev)
                 } else {
                         /* Update stats */
                         ndev->stats.tx_packets++;
-                        ndev->stats.tx_bytes += skb->len;
+                        ndev->stats.tx_bytes += skblen;
                 }
-                dev_kfree_skb_irq(skb);
 
                 txcidx = readl(LPC_ENET_TXCONSUMEINDEX(pldat->net_base));
         }
@@ -1132,7 +1130,7 @@ static int lpc_eth_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
         memcpy(pldat->tx_buff_v + txidx * ENET_MAXF_SIZE, skb->data, len);
 
         /* Save the buffer and increment the buffer counter */
-        pldat->skb[txidx] = skb;
+        pldat->skblen[txidx] = len;
         pldat->num_used_tx_buffs++;
 
         /* Start transmit */
@@ -1147,6 +1145,7 @@ static int lpc_eth_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 
         spin_unlock_irq(&pldat->lock);
 
+        dev_kfree_skb(skb);
         return NETDEV_TX_OK;
 }