From 2600636065406dc14948ac2d2913c66c51be80d5 Mon Sep 17 00:00:00 2001 From: Dale Farnsworth Date: Mon, 22 Aug 2005 15:53:29 -0700 Subject: [PATCH] [PATCH] mv643xx: add workaround for HW checksum generation bug [PATCH] [NET] mv643xx: add workaround for HW checksum generation bug The hardware checksum generator on the mv64xxx occasionally generates an incorrect checksum. This patch works around the issue and enables hardware checksum generation. Signed-off-by: Dale Farnsworth Signed-off-by: Jeff Garzik --- drivers/net/mv643xx_eth.c | 29 ++++++++++++++++++----------- drivers/net/mv643xx_eth.h | 4 +++- 2 files changed, 21 insertions(+), 12 deletions(-) diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c index 0405e1f0d3d..fb6b232069d 100644 --- a/drivers/net/mv643xx_eth.c +++ b/drivers/net/mv643xx_eth.c @@ -1157,16 +1157,20 @@ static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev) if (!skb_shinfo(skb)->nr_frags) { linear: if (skb->ip_summed != CHECKSUM_HW) { + /* Errata BTS #50, IHL must be 5 if no HW checksum */ pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT | - ETH_TX_FIRST_DESC | ETH_TX_LAST_DESC; + ETH_TX_FIRST_DESC | + ETH_TX_LAST_DESC | + 5 << ETH_TX_IHL_SHIFT; pkt_info.l4i_chk = 0; } else { - u32 ipheader = skb->nh.iph->ihl << 11; pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT | - ETH_TX_FIRST_DESC | ETH_TX_LAST_DESC | - ETH_GEN_TCP_UDP_CHECKSUM | - ETH_GEN_IP_V_4_CHECKSUM | ipheader; + ETH_TX_FIRST_DESC | + ETH_TX_LAST_DESC | + ETH_GEN_TCP_UDP_CHECKSUM | + ETH_GEN_IP_V_4_CHECKSUM | + skb->nh.iph->ihl << ETH_TX_IHL_SHIFT; /* CPU already calculated pseudo header checksum. */ if (skb->nh.iph->protocol == IPPROTO_UDP) { pkt_info.cmd_sts |= ETH_UDP_FRAME; @@ -1193,7 +1197,6 @@ linear: stats->tx_bytes += pkt_info.byte_cnt; } else { unsigned int frag; - u32 ipheader; /* Since hardware can't handle unaligned fragments smaller * than 9 bytes, if we find any, we linearize the skb @@ -1222,12 +1225,16 @@ linear: DMA_TO_DEVICE); pkt_info.l4i_chk = 0; pkt_info.return_info = 0; - pkt_info.cmd_sts = ETH_TX_FIRST_DESC; - if (skb->ip_summed == CHECKSUM_HW) { - ipheader = skb->nh.iph->ihl << 11; - pkt_info.cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM | - ETH_GEN_IP_V_4_CHECKSUM | ipheader; + if (skb->ip_summed != CHECKSUM_HW) + /* Errata BTS #50, IHL must be 5 if no HW checksum */ + pkt_info.cmd_sts = ETH_TX_FIRST_DESC | + 5 << ETH_TX_IHL_SHIFT; + else { + pkt_info.cmd_sts = ETH_TX_FIRST_DESC | + ETH_GEN_TCP_UDP_CHECKSUM | + ETH_GEN_IP_V_4_CHECKSUM | + skb->nh.iph->ihl << ETH_TX_IHL_SHIFT; /* CPU already calculated pseudo header checksum. */ if (skb->nh.iph->protocol == IPPROTO_UDP) { pkt_info.cmd_sts |= ETH_UDP_FRAME; diff --git a/drivers/net/mv643xx_eth.h b/drivers/net/mv643xx_eth.h index 57c4f8fbfdb..7678b59c295 100644 --- a/drivers/net/mv643xx_eth.h +++ b/drivers/net/mv643xx_eth.h @@ -49,7 +49,7 @@ /* Checksum offload for Tx works for most packets, but * fails if previous packet sent did not use hw csum */ -#undef MV643XX_CHECKSUM_OFFLOAD_TX +#define MV643XX_CHECKSUM_OFFLOAD_TX #define MV643XX_NAPI #define MV643XX_TX_FAST_REFILL #undef MV643XX_RX_QUEUE_FILL_ON_TASK /* Does not work, yet */ @@ -217,6 +217,8 @@ #define ETH_TX_ENABLE_INTERRUPT (BIT23) #define ETH_AUTO_MODE (BIT30) +#define ETH_TX_IHL_SHIFT 11 + /* typedefs */ typedef enum _eth_func_ret_status {