From owner-freebsd-hackers Tue Mar 11 09:05:36 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id JAA19438 for hackers-outgoing; Tue, 11 Mar 1997 09:05:36 -0800 (PST) Received: from who.cdrom.com (who.cdrom.com [204.216.27.3]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id JAA19424 for ; Tue, 11 Mar 1997 09:05:31 -0800 (PST) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by who.cdrom.com (8.8.5/8.6.11) with SMTP id JAA10825 for ; Tue, 11 Mar 1997 09:05:21 -0800 (PST) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id RAA00539; Tue, 11 Mar 1997 17:17:46 +0100 From: Luigi Rizzo Message-Id: <199703111617.RAA00539@labinfo.iet.unipi.it> Subject: Re: performance (was: 100 Mb/s cards) To: dennis@etinc.com (dennis) Date: Tue, 11 Mar 1997 17:17:45 +0100 (MET) Cc: msmith@atrad.adelaide.edu.au, hackers@freebsd.org In-Reply-To: <3.0.32.19970311102342.00b05710@etinc.com> from "dennis" at Mar 11, 97 10:23:29 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > The comment implies that there is something "stupid" about the controllers > quad alignment requirement, but whoever wrote that should know that all > PCI bus master accesses MUST be quad aligned as a basic requirement > of the spec. Pardon me, but you can still write arbitrary bytes of a quadword by setting the proper byte enables. So there is nothing wrong -- in principle -- in specifying unaligned addresses for the receive buffers. Of course the hardware might be a little bit more complex, but that's another matter. Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________