Patchwork [net-next,--,take,2] igb: allow tx of pre-formatted vlan tagged packets

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Submitter Arthur Jones
Date March 17, 2009, 5:39 p.m.
Message ID <20090317173924.GA13723@ajones-laptop.nbttech.com>
Download mbox | patch
Permalink /patch/24565/
State Awaiting Upstream
Delegated to: David Miller
Headers show

Comments

Arthur Jones - March 17, 2009, 5:39 p.m.
When the 82575 is fed 802.1q packets, it chokes with
an error of the form:

igb 0000:08:00.1: partial checksum but proto=81

As the logic there was not smart enough to look into
the vlan header to pick out the encapsulated protocol.

There are times when we'd like to send these packets
out without having to configure a vlan on the interface.
Here we check for the vlan tag and allow the packet to
go out with the correct hardware checksum.

Thanks to Kand Ly <kand@riverbed.com> for discovering the
issue and the coming up with a solution.  This patch is
based upon his work.

Fixups from Stephen Hemminger <shemminger@vyatta.com> and
Alexander Duyck <alexander.h.duyck@intel.com>.

Signed-off-by: Arthur Jones <ajones@riverbed.com>
---
 drivers/net/igb/igb_main.c |   13 ++++++++++++-
 1 files changed, 12 insertions(+), 1 deletions(-)
David Miller - March 19, 2009, 6:40 a.m.
From: Arthur Jones <ajones@riverbed.com>
Date: Tue, 17 Mar 2009 10:39:24 -0700

> When the 82575 is fed 802.1q packets, it chokes with
> an error of the form:
> 
> igb 0000:08:00.1: partial checksum but proto=81
> 
> As the logic there was not smart enough to look into
> the vlan header to pick out the encapsulated protocol.
> 
> There are times when we'd like to send these packets
> out without having to configure a vlan on the interface.
> Here we check for the vlan tag and allow the packet to
> go out with the correct hardware checksum.
> 
> Thanks to Kand Ly <kand@riverbed.com> for discovering the
> issue and the coming up with a solution.  This patch is
> based upon his work.
> 
> Fixups from Stephen Hemminger <shemminger@vyatta.com> and
> Alexander Duyck <alexander.h.duyck@intel.com>.
> 
> Signed-off-by: Arthur Jones <ajones@riverbed.com>

Jeff, are you queueing this one up?
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Patch

diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c
index 7124f59..26742dd 100644
--- a/drivers/net/igb/igb_main.c
+++ b/drivers/net/igb/igb_main.c
@@ -3030,7 +3030,18 @@  static inline bool igb_tx_csum_adv(struct igb_adapter *adapter,
 		tu_cmd |= (E1000_TXD_CMD_DEXT | E1000_ADVTXD_DTYP_CTXT);
 
 		if (skb->ip_summed == CHECKSUM_PARTIAL) {
-			switch (skb->protocol) {
+			__be16 protocol;
+
+			if (skb->protocol == cpu_to_be16(ETH_P_8021Q)) {
+				const struct vlan_ethhdr *vhdr =
+					vlan_eth_hdr(skb);
+
+				protocol = vhdr->h_vlan_encapsulated_proto;
+			} else {
+				protocol = skb->protocol;
+			}
+
+			switch (protocol) {
 			case cpu_to_be16(ETH_P_IP):
 				tu_cmd |= E1000_ADVTXD_TUCMD_IPV4;
 				if (ip_hdr(skb)->protocol == IPPROTO_TCP)