From mboxrd@z Thu Jan  1 00:00:00 1970
From: liviu.dudau@arm.com (liviu.dudau at arm.com)
Date: Wed, 13 Jan 2016 10:09:11 +0000
Subject: [PATCH v1 3/3] ARM64 LPC: update binding doc
In-Reply-To: <4052627.BRvFkUij6q@wuerfel>
References: <1451396032-23708-1-git-send-email-zourongrong@gmail.com>
 <5694C6A4.8060308@huawei.com>
 <20160112101418.GO13633@e106497-lin.cambridge.arm.com>
 <4052627.BRvFkUij6q@wuerfel>
Message-ID: <20160113100911.GU13633@e106497-lin.cambridge.arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, Jan 12, 2016 at 11:54:59PM +0100, Arnd Bergmann wrote:
> On Tuesday 12 January 2016 10:14:18 liviu.dudau at arm.com wrote:
> > 
> > OK, looking at of_translate_one() comments it looks like a missing "ranges" property is
> > only accepted on PowerPC. I suggest you have an empty "ranges" property in your isa
> > parent node, that will signal to the OF parsing code that the mapping is 1:1. Then have
> > the IPMI node use the reg = <0x0 0xe4 4>; property values instead of reg = <0x1 0xe4 4>;
> > 
> > 
> 
> A missing ranges property means that there is no translation, while an
> empty ranges means a 1:1 translation to the parent bus.
> 
> We really want the former here, as I/O port addresses are not mapped into
> the MMIO space of the parent bus.

Agree. However of_translate_one()'s behaviour doesn't match our expectations and I have no
useful suggestions on what the right behaviour should be.

Best regards,
Liviu

> 
> 	Arnd
> 

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