Re: [BUG] bnx2 + vlan + TSO : doesnt work

[Ben Hutchings <bhutchings@solarflare.com>]

On Tue, 2011-01-18 at 00:41 +0100, Eric Dumazet wrote:
> Oh well, my dev machine, with bnx2 and tg3 NICs, isnt working at all
> with current linux-2.6 tree (I need vlans on my setup)
> 
> tg3 : vlan not working
> 
> bnx2 : vlan + TSO not working (or very slowly, since only non GSO frames
> are OK)
> 
> I suspect recent commits from Jesse are the problem.
> (bnx2_xmit() is feeded with zeroed vlan_tci skbs)
> 
> Maybe f01a5236bd4b1401 (net offloading: Generalize
> netif_get_vlan_features().) ?
> 
> I dont see NETIF_F_HW_VLAN_TX being set in vlan_features in net drivers.
> They only set this flag in dev->features
> 
> I dont think changing all drivers to also set vlan_features makes sense.
> 
> Is following patch the right path ? (It does solve my problem)

This isn't right.  NETIF_F_HW_VLAN_TX in vlan_features would mean that
the hardware can do two levels of VLAN tag insertion, which is generally
not true.

Ben.

> diff --git a/net/core/dev.c b/net/core/dev.c
> index 54277df..5c13e55 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -5265,6 +5265,9 @@ int register_netdevice(struct net_device *dev)
>  	 */
>  	dev->vlan_features |= (NETIF_F_GRO | NETIF_F_HIGHDMA);
>  
> +	/* allow netif_skb_features() not mask this bit from dev->features */
> +	dev->vlan_features |= NETIF_F_HW_VLAN_TX;
> +
>  	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
>  	ret = notifier_to_errno(ret);
>  	if (ret)

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.