From mboxrd@z Thu Jan  1 00:00:00 1970
From: Lennert Buytenhek <buytenh@wantstofly.org>
Subject: Re: [PATCH] net: add Fast Ethernet driver for PXA168.
Date: Tue, 10 Aug 2010 13:40:32 +0200
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Cc: Sachin Sanap <ssanap@marvell.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Ashish Karkare <akarkare@marvell.com>,
	Prabhanjan Sarnaik <sarnaik@marvell.com>,
	"eric.y.miao@gmail.com" <eric.y.miao@gmail.com>,
	Mark Brown <markb@marvell.com>
To: Philip Rakity <prakity@marvell.com>
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On Fri, Aug 06, 2010 at 08:44:02AM -0700, Philip Rakity wrote:

> You should change
> 
> >>> +		skb = dev_alloc_skb(MAX_PKT_SIZE + ETH_HW_IP_ALIGN);
> 
> >> 
> 
> to allocatie ADDITIONAL prepend space in the header.  If you are doing
> ethernet to 802.11 routing or bridging then the wireless driver will
> not have enough space in front of the header to prepend its headers
> without having to allocate additional space.

This seems like something that, should you want to handle it, should be
handled centrally (e.g. by conditionally increasing NET_SKB_PAD or so)
and not hardcoded into one specific driver only.