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Re: lift the ioport_resource limit ...

To: Jun Sun <jsun@mvista.com>
Subject: Re: lift the ioport_resource limit ...
From: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
Date: Thu, 10 May 2001 11:43:36 +0200 (MET DST)
Cc: Ralf Baechle <ralf@oss.sgi.com>, linux-mips@oss.sgi.com
In-reply-to: <3AF9B173.5E13AD2@mvista.com>
Organization: Technical University of Gdansk
Sender: owner-linux-mips@oss.sgi.com
On Wed, 9 May 2001, Jun Sun wrote:

> The PCI IO space essentially extends the ISA bus, which effectively removes
> the 0xffff limits.

 Note that while there is usually no problem with using addresses beyond
64kB in the PCI I/O space, certain PCI-to-PCI bridges may not pass such
accesses across.  So it's best to avoid assigning and using them.  That's
why Linux remaps "high" I/O space resources on Alpha, which get set up for
some systems by the SRM console (firmware), e.g. in the system I was using
a few years ago, SRM used to assign addresses around 0x11000 and 0x12000
for the onboard network and SCSI devices, IIRC. 

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +


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