[PATCH 6/8] arm: mach-armada: add support for Armada XP board with device tree

[Russell King - ARM Linux]

On Tue, May 15, 2012 at 04:59:08PM +0100, Ben Dooks wrote:
> On 15/05/12 16:41, Russell King - ARM Linux wrote:
>> On Tue, May 15, 2012 at 04:07:59PM +0100, Ben Dooks wrote:
>>> I think it was because that PCI was initialised early and requires a
>>> large mapping space. It is very likely to be legacy kernel stuff that
>>> people have kept copying through.
>>
>> No.  PCI needs nothing other than access to the configuration space, and
>> the PCI IO window.  There has _never_ been any hard requirement to map
>> PCI memory in map_io() because that is _always_ done by drivers calling
>> ioremap().
>
> What about inb, outb and their related functions?

I said:
| No.  PCI needs nothing other than access to the configuration space, and
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| the PCI IO window.
  ^^^^^^^^^^^^^^^^^^

And, as everyone should know, inb(), outb() etc are the PCI/ISA IO
accessors. So... if you have the PCI IO window mapped, then inb() et.al.
use _that_ window and there isn't a problem.