From 5176da7e5318669220e4d2fa856223054a3efc9f Mon Sep 17 00:00:00 2001 From: Baruch Siach Date: Tue, 2 Dec 2008 05:07:01 +0000 Subject: [PATCH 1/1] enc28j60: Fix sporadic packet loss (corrected again) Packet data read from the RX buffer the when the RSV is at the end of the RX buffer does not warp around. This causes packet loss, as the actual data is never read. Fix this by calculating the right packet data location. Thanks to Shachar Shemesh for suggesting the fix. Signed-off-by: Baruch Siach Acked-by: Claudio Lanconelli Signed-off-by: David S. Miller --- drivers/net/enc28j60.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/net/enc28j60.c b/drivers/net/enc28j60.c index e1b441e..c414554 100644 --- a/drivers/net/enc28j60.c +++ b/drivers/net/enc28j60.c @@ -568,6 +568,17 @@ static u16 erxrdpt_workaround(u16 next_packet_ptr, u16 start, u16 end) return erxrdpt; } +/* + * Calculate wrap around when reading beyond the end of the RX buffer + */ +static u16 rx_packet_start(u16 ptr) +{ + if (ptr + RSV_SIZE > RXEND_INIT) + return (ptr + RSV_SIZE) - (RXEND_INIT - RXSTART_INIT + 1); + else + return ptr + RSV_SIZE; +} + static void nolock_rxfifo_init(struct enc28j60_net *priv, u16 start, u16 end) { u16 erxrdpt; @@ -938,8 +949,9 @@ static void enc28j60_hw_rx(struct net_device *ndev) skb->dev = ndev; skb_reserve(skb, NET_IP_ALIGN); /* copy the packet from the receive buffer */ - enc28j60_mem_read(priv, priv->next_pk_ptr + sizeof(rsv), - len, skb_put(skb, len)); + enc28j60_mem_read(priv, + rx_packet_start(priv->next_pk_ptr), + len, skb_put(skb, len)); if (netif_msg_pktdata(priv)) dump_packet(__func__, skb->len, skb->data); skb->protocol = eth_type_trans(skb, ndev); -- 1.7.9.5