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Date: Mon, 05 Dec 2011 15:16:28 +0100
From: Andre Oppermann <andre@freebsd.org>
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To: Jack Vogel <jfvogel@gmail.com>
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Cc: FreeBSD Net <freebsd-net@freebsd.org>
Subject: Re: VLAN HWTSO question/problem
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On 02.12.2011 21:06, Jack Vogel wrote:
> I have just discovered during some validation testing on the em driver,
> that if HWTSO is enabled
> at the same time as VLAN_HWTAGGING and/or VLAN_HWFILTER that its broken.
>
> Looking at the vlan source its not obvious why this would be the case, but
> netperf just fails completely.
> I can turn TAGGING off and I can get TSO, or turn off TSO and get
> TAGGING/FILTERING, but not
> both :(
>
> My tester only has 8.2 to try this on, not sure if its a bug or a design
> limitation, can someone
> enlighten me?  At the moment I'm thinking of just turning HWTSO off by
> default?

Maybe the HW or drive chokes on the overall ethernet frame being longer
than 64K due to the VLAN header even though the IP packet part stays
within the limits?

-- 
Andre