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Re: [patch] linux: declance multicast filter fixes

To: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
Subject: Re: [patch] linux: declance multicast filter fixes
From: Harald Koerfgen <hkoerfg@web.de>
Date: Fri, 29 Mar 2002 08:57:50 +0100
Cc: Dave Airlie <airlied@csn.ul.ie>, Ralf Baechle <ralf@uni-koblenz.de>, linux-mips@fnet.fr, linux-mips@oss.sgi.com
In-reply-to: <Pine.GSO.3.96.1020328134253.11187B-100000@delta.ds2.pg.gda.pl>
Organization: none to speak of
References: <Pine.GSO.3.96.1020328134253.11187B-100000@delta.ds2.pg.gda.pl>
Sender: hkoerfg@web.de
On Thursday 28 March 2002 14:01, Maciej W. Rozycki wrote:
>  But the I/O ASIC chip is smart enough to merge data from the 8-bit ROM
> device without problems and present four consecutive bytes as 32-bit
> quantities to the host CPU.

A simple 4 to 1 mapping is easy, even for the average hardware developer :-)

> Why couldn't it do the same for the LANCE?
> Host memory addresses are generated on behalf of the LANCE by the I/O ASIC
> anyway.

Probably because this would have made the IOASIC 0.0034 cents more expensive?

> Of course not all designers have a clue, sigh...  A brief study of
> available documentation suggests no merging mode was implemented for the
> LANCE and bit 0 of addresses generated is simply hardwired to 0. :-(

That's my interpretation as well.

Greetings,
Harald

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