From owner-freebsd-hackers  Fri Mar  7 10:45: 6 2003
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Message-ID: <3E68E859.EAB20A71@mindspring.com>
Date: Fri, 07 Mar 2003 10:43:37 -0800
From: Terry Lambert <tlambert2@mindspring.com>
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To: Wes Peters <wes@softweyr.com>
Cc: Paulo Roberto <nirv199@yahoo.com>,
	Bram Van Dam <gandalfbram@pandora.be>, freebsd-hackers@freebsd.org
Subject: Re: Realtek
References: <20030306230206.70461.qmail@web14913.mail.yahoo.com> <200303062136.44471.wes@softweyr.com>
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Wes Peters wrote:
> The problem with the RealTek chipset is that the packets have to be
> aligned on some completely stupid boundary in memory (32 bytes if memory
> serves).  The driver code ends up copying the packet data to a tempory
> buffer before sending it for almost every outgoing packet, which is just
> totally stupid.

And TCP/IP headers are not an even multiple of the alignment boundary
(4 bytes, actually).  So every packet the card DMA's in has to be
copied so that access to the TCP packet contents are aligned.

-- Terry

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