From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthew Jacob <mjacob@feral.com>
Subject: Re: qla2xxx and feral ISP updates in their respective BK trees
Date: Fri, 20 Jun 2003 11:39:26 -0700 (PDT)
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To: Jeff Garzik <jgarzik@pobox.com>
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>
> Is there hardware that supports both PIO and MMIO... and actually
> prefers PIO?
>
> I know of no such situation -- outside of hardware bugs and driver bugs,
> which force the use of PIO, where both are available.
>
> Pretty much everybody prefers memory mapped registers :)
>

Of course. But there are two things that mitigate MMIO vs. PIO-

a) Historically, MMIO has been buggy on ia32. This is no longer the
case, but there definitely were a lot of platforms with this broken.

b) MMIO is consumption of mapping resources, while PIO isn't.