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Subject: Re: [PATCH/RFC v3] introduce ARCH_CAN_UNALIGNED_ACCESS Kconfig
	symbol
From: Harvey Harrison <harvey.harrison@gmail.com>
To: Johannes Berg <johannes@sipsolutions.net>
Cc: Sam Ravnborg <sam@ravnborg.org>, Daniel Drake <dsd@gentoo.org>,
	Linux Kernel list <linux-kernel@vger.kernel.org>,
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	netdev <netdev@vger.kernel.org>
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Date: Thu, 20 Mar 2008 12:09:11 -0700
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On Thu, 2008-03-20 at 19:45 +0100, Johannes Berg wrote:
> +For some ethernet hardware that cannot DMA to unaligned addresses like
> +4*n+2 or non-ethernet hardware, this can be a problem, and it is then
> +required to copy the incoming frame into an aligned buffer. Because this is
> +unnecessary on architectures that can do unaligned accesses, the code can be
> +made depend on CONFIG_HAVE_UNALIGNED_ACCESS_SUPPORT like so:
> +
> +#ifdef CONFIG_HAVE_UNALIGNED_ACCESS_SUPPORT
> +	skb = original skb
> +#else
> +	skb = copy skb
> +#endif
> +

Couldn't this just be made an inline in a networking header somewhere,
instead of ifdefs in the code?

Harvey