From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alex Dubov <oakad@yahoo.com>
Subject: Re: Bad TCP timestamps on non-PC platforms
Date: Sun, 9 Jan 2011 22:33:40 -0800 (PST)
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Cc: Eric Dumazet <eric.dumazet@gmail.com>, netdev@vger.kernel.org,
	David Miller <davem@davemloft.net>
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> > Any ideas where this particular problem may
> originate?
> 
> Is there a bug in checksum offload in the driver?
> Does the hardware correctly handle checksum of packets that
> are
> unaligned or whose length is an odd number of bytes?
> 
> If the hardware can't do checksum correctly, the driver
> should either
> disable checksum offload or in worst case copy the packet
> to a new
> buffer that is in a known safe place.

I managed to work around the issue by clearing the NETIF_F_IP_CSUM
feature flag of the gianfar network driver, so it appears the bug is
indeed somewhere there.