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Subject[34-longterm 187/196] vmxnet3: Fix inconsistent LRO state after initialization
From: Thomas Jarosch <>

This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
commit ebde6f8acba92abfc203585198a54f47e83e2cd0 upstream.

During initialization of vmxnet3, the state of LRO
gets out of sync with netdev->features.

This leads to very poor TCP performance in a IP forwarding
setup and is hitting many VMware users.

Simplified call sequence:
1. vmxnet3_declare_features() initializes "adapter->lro" to true.

2. The kernel automatically disables LRO if IP forwarding is enabled,
so vmxnet3_set_flags() gets called. This also updates netdev->features.

3. Now vmxnet3_setup_driver_shared() is called. "adapter->lro" is still
set to true and LRO gets enabled again, even though
netdev->features shows it's disabled.

Fix it by updating "adapter->lro", too.

The private vmxnet3 adapter flags are scheduled for removal
in net-next, see commit a0d2730c9571aeba793cb5d3009094ee1d8fda35
"net: vmxnet3: convert to hw_features".

Patch applies to 2.6.37 / 2.6.38 and 2.6.39-rc6.

Please CC: comments.

Signed-off-by: Thomas Jarosch <>
Acked-by: Stephen Hemminger <>
Signed-off-by: David S. Miller <>
Signed-off-by: Paul Gortmaker <>
drivers/net/vmxnet3/vmxnet3_ethtool.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/vmxnet3/vmxnet3_ethtool.c b/drivers/net/vmxnet3/vmxnet3_ethtool.c
index 3935c44..df7cddd 100644
--- a/drivers/net/vmxnet3/vmxnet3_ethtool.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethtool.c
@@ -290,6 +290,9 @@ vmxnet3_set_flags(struct net_device *netdev, u32 data) {
/* toggle the LRO feature*/
netdev->features ^= NETIF_F_LRO;

+ /* Update private LRO flag */
+ adapter->lro = lro_requested;
/* update harware LRO capability accordingly */
if (lro_requested)
adapter->shared->devRead.misc.uptFeatures &= UPT1_F_LRO;

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