diff options
author | Michael Chan <mchan@broadcom.com> | 2006-06-30 03:15:54 (GMT) |
---|---|---|
committer | David S. Miller <davem@sunset.davemloft.net> | 2006-06-30 21:11:57 (GMT) |
commit | 52c0fd834ea0e7c6ef8616ce0a1f85bac4233ed7 (patch) | |
tree | 92897bedf97906699f654fd94985fbada0497daa /drivers/net/tg3.c | |
parent | 1661394e78b3b2cc868cd0e89c1066974302aaca (diff) | |
download | linux-fsl-qoriq-52c0fd834ea0e7c6ef8616ce0a1f85bac4233ed7.tar.xz |
[TG3]: Add TSO workaround using GSO
Use GSO to workaround a rare TSO bug on some chips. This hardware
bug may be triggered when the TSO header size is greater than 80
bytes. When this condition is detected in a TSO packet, the driver
will use GSO to segment the packet to workaround the hardware bug.
Thanks to Juergen Kreileder <jk@blackdown.de> for reporting the
problem and collecting traces to help debug the problem.
And thanks to Herbert Xu <herbert@gondor.apana.org.au> for providing
the GSO mechanism that happens to be the perfect workaround for this
problem.
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/tg3.c')
-rw-r--r-- | drivers/net/tg3.c | 53 |
1 files changed, 49 insertions, 4 deletions
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c index 2c36e70..63d4b2c 100644 --- a/drivers/net/tg3.c +++ b/drivers/net/tg3.c @@ -3880,6 +3880,40 @@ out_unlock: return NETDEV_TX_OK; } +#if TG3_TSO_SUPPORT != 0 +static int tg3_start_xmit_dma_bug(struct sk_buff *, struct net_device *); + +/* Use GSO to workaround a rare TSO bug that may be triggered when the + * TSO header is greater than 80 bytes. + */ +static int tg3_tso_bug(struct tg3 *tp, struct sk_buff *skb) +{ + struct sk_buff *segs, *nskb; + + /* Estimate the number of fragments in the worst case */ + if (unlikely(TX_BUFFS_AVAIL(tp) <= (skb_shinfo(skb)->gso_segs * 3))) { + netif_stop_queue(tp->dev); + return NETDEV_TX_BUSY; + } + + segs = skb_gso_segment(skb, tp->dev->features & ~NETIF_F_TSO); + if (unlikely(IS_ERR(segs))) + goto tg3_tso_bug_end; + + do { + nskb = segs; + segs = segs->next; + nskb->next = NULL; + tg3_start_xmit_dma_bug(nskb, tp->dev); + } while (segs); + +tg3_tso_bug_end: + dev_kfree_skb(skb); + + return NETDEV_TX_OK; +} +#endif + /* hard_start_xmit for devices that have the 4G bug and/or 40-bit bug and * support TG3_FLG2_HW_TSO_1 or firmware TSO only. */ @@ -3916,7 +3950,7 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev) mss = 0; if (skb->len > (tp->dev->mtu + ETH_HLEN) && (mss = skb_shinfo(skb)->gso_size) != 0) { - int tcp_opt_len, ip_tcp_len; + int tcp_opt_len, ip_tcp_len, hdr_len; if (skb_header_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { @@ -3927,11 +3961,16 @@ static int tg3_start_xmit_dma_bug(struct sk_buff *skb, struct net_device *dev) tcp_opt_len = ((skb->h.th->doff - 5) * 4); ip_tcp_len = (skb->nh.iph->ihl * 4) + sizeof(struct tcphdr); + hdr_len = ip_tcp_len + tcp_opt_len; + if (unlikely((ETH_HLEN + hdr_len) > 80) && + (tp->tg3_flags2 & TG3_FLG2_HW_TSO_1_BUG)) + return (tg3_tso_bug(tp, skb)); + base_flags |= (TXD_FLAG_CPU_PRE_DMA | TXD_FLAG_CPU_POST_DMA); skb->nh.iph->check = 0; - skb->nh.iph->tot_len = htons(mss + ip_tcp_len + tcp_opt_len); + skb->nh.iph->tot_len = htons(mss + hdr_len); if (tp->tg3_flags2 & TG3_FLG2_HW_TSO) { skb->h.th->check = 0; base_flags &= ~TXD_FLAG_TCPUDP_CSUM; @@ -10192,8 +10231,14 @@ static int __devinit tg3_get_invariants(struct tg3 *tp) GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5787) { tp->tg3_flags2 |= TG3_FLG2_HW_TSO_2; tp->tg3_flags2 |= TG3_FLG2_1SHOT_MSI; - } else - tp->tg3_flags2 |= TG3_FLG2_HW_TSO_1; + } else { + tp->tg3_flags2 |= TG3_FLG2_HW_TSO_1 | + TG3_FLG2_HW_TSO_1_BUG; + if (GET_ASIC_REV(tp->pci_chip_rev_id) == + ASIC_REV_5750 && + tp->pci_chip_rev_id >= CHIPREV_ID_5750_C2) + tp->tg3_flags2 &= ~TG3_FLG2_HW_TSO_1_BUG; + } } if (GET_ASIC_REV(tp->pci_chip_rev_id) != ASIC_REV_5705 && |