Re: [PATCH][net-next] gianfar: Fix reported number of sent bytes to BQL

[David Miller <davem@davemloft.net>]

From: Claudiu Manoil <claudiu.manoil@freescale.com>
Date: Fri, 30 Aug 2013 15:01:15 +0300

> Fix the amount of sent bytes reported to BQL by reporting the
> number of bytes on wire in the xmit routine, and recording that
> value for each skb in order to be correctly confirmed on Tx
> confirmation cleanup.
> 
> Reporting skb->len to BQL just before exiting xmit is not correct
> due to possible insertions of TOE block and alignment bytes in the
> skb->data, which are being stripped off by the controller before
> transmission on wire.  This led to mismatch of (incorrectly)
> reported bytes to BQL b/w xmit and Tx confirmation, resulting in
> Tx timeout firing, for the h/w tx timestamping acceleration case.
> 
> There's no easy way to obtain the number of bytes on wire in the Tx
> confirmation routine, so skb->cb is used to convey that information
> from xmit to Tx confirmation, for now (as proposed by Eric). Revived
> the currently unused GFAR_CB() construct for that purpose.
> 
> Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>

Applied.