From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prashant Sreedharan Subject: Re: [PATCH] tg3: Work around HW/FW limitations with vlan encapsulated frames Date: Thu, 18 Sep 2014 16:00:21 -0700 Message-ID: <1411081221.18724.84.camel@prashant> References: <1411050677-28147-1-git-send-email-vyasevic@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , Vladislav Yasevich , Michael Chan To: Vladislav Yasevich Return-path: Received: from mail-gw3-out.broadcom.com ([216.31.210.64]:18234 "EHLO mail-gw3-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750895AbaIRXKS (ORCPT ); Thu, 18 Sep 2014 19:10:18 -0400 In-Reply-To: <1411050677-28147-1-git-send-email-vyasevic@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2014-09-18 at 10:31 -0400, Vladislav Yasevich wrote: > TG3 appears to have an issue performing TSO and checksum offloading > correclty when the frame has been vlan encapsulated (non-accelrated). > In these cases, tcp checksum is not correctly updated. Yes that is true for inline vlan headers, to clarify was TSO and checksum offload working for accelerated 802.1ad packets ? > This patch attempts to work around this issue. After the patch, > 802.1ad vlans start working correctly over tg3 devices. > > CC: Prashant Sreedharan > CC: Michael Chan > Signed-off-by: Vladislav Yasevich > --- > drivers/net/ethernet/broadcom/tg3.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c > index cb77ae9..e7d3a62 100644 > --- a/drivers/net/ethernet/broadcom/tg3.c > +++ b/drivers/net/ethernet/broadcom/tg3.c > @@ -7914,8 +7914,6 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) > > entry = tnapi->tx_prod; > base_flags = 0; > - if (skb->ip_summed == CHECKSUM_PARTIAL) > - base_flags |= TXD_FLAG_TCPUDP_CSUM; > > mss = skb_shinfo(skb)->gso_size; > if (mss) { > @@ -7929,6 +7927,13 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) > > hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb) - ETH_HLEN; > > + /* HW/FW can not correctly segment packets that have been > + * vlan encapsulated. > + */ > + if (skb->protocol == htons(ETH_P_8021Q) || > + skb->protocol == htons(ETH_P_8021AD)) > + return tg3_tso_bug(tp, tnapi, txq, skb); I think skb_gso_segment() would return skbs that would still have checksum offloaded to the chip. > + > if (!skb_is_gso_v6(skb)) { > if (unlikely((ETH_HLEN + hdr_len) > 80) && > tg3_flag(tp, TSO_BUG)) > @@ -7979,6 +7984,17 @@ static netdev_tx_t tg3_start_xmit(struct sk_buff *skb, struct net_device *dev) > base_flags |= tsflags << 12; > } > } > + } else if (skb->ip_summed == CHECKSUM_PARTIAL) { > + /* HW/FW can not correctly checksum packets that have been > + * vlan encapsulated. > + */ > + if (skb->protocol == htons(ETH_P_8021Q) || > + skb->protocol == htons(ETH_P_8021AD)) { > + if (skb_checksum_help(skb)) > + goto drop; > + } else { > + base_flags |= TXD_FLAG_TCPUDP_CSUM; > + } > } > > if (tg3_flag(tp, USE_JUMBO_BDFLAG) && Instead of the above workarounds since the chips supported by tg3 does not support checksum offload and TSO for inline vlan headers, these features can be disabled/cleared in dev->vlan_features. Side effect is accelerated vlan headers will also have TSO and checksum offload disabled. Also as part of this review, found a problem with the receive section of the driver it was not checking for 802.1ad vlan protocol and dropping 802.1ad vlan packets of size > mtu + ETH_HLEN diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index cb77ae9..620887a 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -6918,7 +6918,8 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget) skb->protocol = eth_type_trans(skb, tp->dev); if (len > (tp->dev->mtu + ETH_HLEN) && - skb->protocol != htons(ETH_P_8021Q)) { + skb->protocol != htons(ETH_P_8021Q) && + skb->protocol != htons(ETH_P_8021AD)) { dev_kfree_skb_any(skb); goto drop_it_no_recycle; }