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From: David Miller <davem@davemloft.net>
Subject: Re: Gianfar: RX Recycle skb->len error
Date: Mon, 22 Mar 2010 20:30:53 -0700 (PDT)
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From: "Ben Menchaca (ben@bigfootnetworks.com)" <ben@bigfootnetworks.com>
Date: Mon, 22 Mar 2010 14:10:48 -0700

> 	It's yucky, but skb_reserve(skb, -alignamount) works,

I have no problem with people using that.

> 	It seems in both these cases for gianfar, the amount of the
> 	alignment is not immediately available to the code the
> 	recognizes that the skb_reset_reserved() is required.  A bit
> 	larger rework appears to be needed.

There's no need to make this so complicated.  Just remember the
value and then refer to it later, when needed.

struct gianfar_skb_cb {
       int	alignamount;
};

#define GIANFAR_CB(skb) ((struct gianfar_skb_cb *)((skb)->cb))

...
	GIANFAR_CB(skb)->alignamount = alignamount;
...

		skb_reserve(skb, -GIANFAR_CB(skb)->alignamount);