[PATCH] [NET] mv643xx: add workaround for HW checksum generation bug
DORMANTno replies
From: Dale Farnsworth <hidden>
Date: 2005-08-22 22:53:29
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
[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 <redacted> --- commit 42b926194c0e88445e654b8f11faf199d1409650 tree 0dfda571d490d3d67ee5fc14f473390efeabef84 parent f6fdd7d9c273bb2a20ab467cb57067494f932fa3 author Dale Farnsworth [off-list ref] Mon, 22 Aug 2005 15:43:49 -0700 committer Dale Farnsworth [off-list ref] Mon, 22 Aug 2005 15:43:49 -0700 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
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c@@ -1157,16 +1157,20 @@ static int mv643xx_eth_start_xmit(struct 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
--- 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 {