Date: Sun, 30 Dec 2007 18:39:27 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Rene Herman <rene.herman@keyaccess.nl>
Cc: Ingo Molnar <mingo@elte.hu>,
       Linus Torvalds <torvalds@linux-foundation.org>, dpreed@reed.com,
       Islam Amer <pharon@gmail.com>, hpa@zytor.com,
       Pavel Machek <pavel@ucw.cz>, Ingo Molnar <mingo@redhat.com>,
       Andi Kleen <andi@firstfloor.org>, Thomas Gleixner <tglx@linutronix.de>,
       Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override
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On Sun, 30 Dec 2007 19:14:40 +0100
Rene Herman <rene.herman@keyaccess.nl> wrote:

> On 30-12-07 17:48, Alan Cox wrote:
> 
> > For processors with TSC I think we should aim for 2.6.25 to do this and 
> > to have the major other _p fixups done. I pity whoever does stuff like 
> > the scc drivers but most of the rest isn't too bad.
> 
> I'm by the way looking at drivers/net/wd.c which my 386 uses for its dual 
> mode NE2000/WD8013 clone ISA NIC and while it specifically needs no delay at 
> all it seems, the mixed use of out and outb_p seems to suggest that someone 
> once thought about that. Would you advice sticking in a udelay(2) manually 
> there?

I would need to dig out the documentation and NE2000 reference code if I
even still have them. From memory NE2K needs them but I don't know
offhand if the WD80x3 devices do, or if only some of them do. It'll also
depend on the port - the DPRAM is different to the 8390.

Don Becker wrote the drivers and at the time he tuned them carefully for
performance so I would expect delays to be the ones needed

Alan
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