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RE: set_io_port_base()?

To: "Ralf Baechle" <ralf@oss.sgi.com>
Subject: RE: set_io_port_base()?
From: "Matthew Dharm" <mdharm@momenco.com>
Date: Wed, 20 Feb 2002 18:05:21 -0800
Cc: "Linux-MIPS" <linux-mips@oss.sgi.com>
Importance: Normal
In-reply-to: <20020221025755.B29466@dea.linux-mips.net>
Sender: owner-linux-mips@oss.sgi.com
If it works as I think it does, then is the code in
linux/arch/mips/gt64120/momenco_ocelot/setup.c correct?  Specifically,
it calls ioremap() and then calls set_io_port_base() with a very
strange value -- it's the value from ioremap() modified by the I/O
physical address base...

That doesn't look right to me... or I just don't quite understand how
this is supposed to work.

Matt

--
Matthew D. Dharm                            Senior Software Designer
Momentum Computer Inc.                      1815 Aston Ave.  Suite 107
(760) 431-8663 X-115                        Carlsbad, CA 92008-7310
Momentum Works For You                      www.momenco.com

> -----Original Message-----
> From: Ralf Baechle [mailto:ralf@oss.sgi.com]
> Sent: Wednesday, February 20, 2002 5:58 PM
> To: Matthew Dharm
> Cc: Linux-MIPS
> Subject: Re: set_io_port_base()?
>
>
> On Wed, Feb 20, 2002 at 05:36:05PM -0800, Matthew Dharm wrote:
>
> > Now, I'm pretty sure this has something to do with the initcall to
> > set_io_port_base() and ioremap(), which are in my setup.c
> (copied from
> > linux/arch/mips/gt64120/momenco_ocelot/setup.c and
> modified).  Without
> > that bit of code at the bottom of that function, I don't even get
> > this -- it just crashes.  So I know I need this code, but
> I'm just not
> > certain what/how I should be using it...
> >
> > My initial guess is that it's used to map some virtual
> address space
> > onto the physical addresses needed to actually generate PCI I/O
> > transactions, but that's just a guess.  If that's right,
> then the code
> > I'm using _should_ work... I call ioremap() with the
> physical base and
> > size, and then set_io_port_base() using the result of ioremap().
>
> That is exactly the intended use.
>
>   Ralf
>


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