From 50ad076ba43d88956707cd9d6849715de5e282bf Mon Sep 17 00:00:00 2001 From: Claudiu Manoil Date: Fri, 30 Aug 2013 15:01:15 +0300 Subject: [PATCH] gianfar: Fix reported number of sent bytes to BQL Fix the amount of sent bytes reported to BQL by reporting the number of bytes on wire in the xmit routine, and recording that value for each skb in order to be correctly confirmed on Tx confirmation cleanup. Reporting skb->len to BQL just before exiting xmit is not correct due to possible insertions of TOE block and alignment bytes in the skb->data, which are being stripped off by the controller before transmission on wire. This led to mismatch of (incorrectly) reported bytes to BQL b/w xmit and Tx confirmation, resulting in Tx timeout firing, for the h/w tx timestamping acceleration case. There's no easy way to obtain the number of bytes on wire in the Tx confirmation routine, so skb->cb is used to convey that information from xmit to Tx confirmation, for now (as proposed by Eric). Revived the currently unused GFAR_CB() construct for that purpose. Signed-off-by: Claudiu Manoil Cc: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/ethernet/freescale/gianfar.c | 18 +++++++++++------- drivers/net/ethernet/freescale/gianfar.h | 2 +- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index b2c91dcd245f..c4eaadeb572f 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2092,7 +2092,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) int do_tstamp, do_csum, do_vlan; u32 bufaddr; unsigned long flags; - unsigned int nr_frags, nr_txbds, length, fcb_len = 0; + unsigned int nr_frags, nr_txbds, bytes_sent, fcb_len = 0; rq = skb->queue_mapping; tx_queue = priv->tx_queue[rq]; @@ -2147,7 +2147,10 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) } /* Update transmit stats */ - tx_queue->stats.tx_bytes += skb->len; + bytes_sent = skb->len; + tx_queue->stats.tx_bytes += bytes_sent; + /* keep Tx bytes on wire for BQL accounting */ + GFAR_CB(skb)->bytes_sent = bytes_sent; tx_queue->stats.tx_packets++; txbdp = txbdp_start = tx_queue->cur_tx; @@ -2167,12 +2170,13 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) } else { /* Place the fragment addresses and lengths into the TxBDs */ for (i = 0; i < nr_frags; i++) { + unsigned int frag_len; /* Point at the next BD, wrapping as needed */ txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size); - length = skb_shinfo(skb)->frags[i].size; + frag_len = skb_shinfo(skb)->frags[i].size; - lstatus = txbdp->lstatus | length | + lstatus = txbdp->lstatus | frag_len | BD_LFLAG(TXBD_READY); /* Handle the last BD specially */ @@ -2182,7 +2186,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) bufaddr = skb_frag_dma_map(priv->dev, &skb_shinfo(skb)->frags[i], 0, - length, + frag_len, DMA_TO_DEVICE); /* set the TxBD length and buffer pointer */ @@ -2250,7 +2254,7 @@ static int gfar_start_xmit(struct sk_buff *skb, struct net_device *dev) lstatus |= BD_LFLAG(TXBD_CRC | TXBD_READY) | skb_headlen(skb); } - netdev_tx_sent_queue(txq, skb->len); + netdev_tx_sent_queue(txq, bytes_sent); /* We can work in parallel with gfar_clean_tx_ring(), except * when modifying num_txbdfree. Note that we didn't grab the lock @@ -2570,7 +2574,7 @@ static void gfar_clean_tx_ring(struct gfar_priv_tx_q *tx_queue) bdp = next_txbd(bdp, base, tx_ring_size); } - bytes_sent += skb->len; + bytes_sent += GFAR_CB(skb)->bytes_sent; dev_kfree_skb_any(skb); diff --git a/drivers/net/ethernet/freescale/gianfar.h b/drivers/net/ethernet/freescale/gianfar.h index 46f56f36118f..04112b98ff5d 100644 --- a/drivers/net/ethernet/freescale/gianfar.h +++ b/drivers/net/ethernet/freescale/gianfar.h @@ -575,7 +575,7 @@ struct rxfcb { }; struct gianfar_skb_cb { - int alignamount; + unsigned int bytes_sent; /* bytes-on-wire (i.e. no FCB) */ }; #define GFAR_CB(skb) ((struct gianfar_skb_cb *)((skb)->cb)) -- 2.30.2