[24/24] vmxnet3: Fix inconsistent LRO state after initialization

From: Greg KH
Date: Thu May 19 2011 - 14:33:10 EST

2.6.33-longterm review patch. If anyone has any objections, please let us know.

Content-Length: 1709
Lines: 52

From: Thomas Jarosch <thomas.jarosch@xxxxxxxxxxxxx>

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 <thomas.jarosch@xxxxxxxxxxxxx>
Acked-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

drivers/net/vmxnet3/vmxnet3_ethtool.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/net/vmxnet3/vmxnet3_ethtool.c
+++ b/drivers/net/vmxnet3/vmxnet3_ethtool.c
@@ -290,6 +290,9 @@ vmxnet3_set_flags(struct net_device *net
/* 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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