Re: [PATCH 1/3] net: lpc_eth: Replace WARN() trace with simple pr_warn()

Eric Dumazet
2012-06-13T06:16:18Z

On Mon, 2012-06-11 at 21:18 +0200, Eric Dumazet wrote:
> On Mon, 2012-06-11 at 11:26 +0200, Roland Stigge wrote:
>
> > Is it sensible at this point to increase the TX buffers anyway? For
> > different reasons of course: We have enough SRAM available and TX
> > buffers (16->32) are still more than RX buffers (48).
>
> I doubt it has any impact on performance for a 100Mbit link ?
>
> One thing that could be done would be to free skbs in
> lpc_eth_hard_start_xmit() instead of __lpc_handle_xmit()
>

Here is the patch I was thinking about

(on top of latest net-next)

Could you please test it ?

drivers/net/ethernet/nxp/lpc_eth.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/nxp/lpc_eth.c b/drivers/net/ethernet/nxp/lpc_eth.c
index 083d671..426f14c 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;
@@ -908,7 +908,7 @@ static void __lpc_handle_xmit(struct net_device *ndev)

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 +945,8 @@ 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 +1131,7 @@ 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 +1146,7 @@ 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;
}