Re: [PATCH] x86: provide a DMI based port 0x80 I/O delay override

From: Bodo Eggert
Date: Mon Dec 31 2007 - 09:40:23 EST


On Sun, 30 Dec 2007, Alan Cox wrote:
> On Sun, 30 Dec 2007 12:53:02 -0800
> "H. Peter Anvin" <hpa@xxxxxxxxx> wrote:
> > Bodo Eggert wrote:

> > > I've never seen code which would do that, and it was not suggested by any
> > > tutorial I ever saw. I'd expect any machine to break on all kinds of software
> > > if it required this. The only thing I remember being warned about is writing
> > > the index and the data register at the same time using outw, because that
> > > would write both registers at the same time on 16-bit-cards.
> > >
> >
> > And we use that, and have been for 15 years. I haven't seen any screams
> > of pain about it.
>
> Actually there were, and I sent numerous people patches for that back in
> ISA days.

Are you talking about VGA cards requiring a delay between outb index/outb
data, VGA cards barfing on outw or systems barfing on outb(0x80,42)?
--
Programming is an art form that fights back.
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