Re: [PATCH v1 3/3] ARM64 LPC: update binding doc

liviu.dudau
2016-01-13T11:26:05Z

On Wed, Jan 13, 2016 at 07:06:42PM +0800, Rongrong Zou wrote:
> On 2016/1/13 18:09, liviu.dudau@arm.com wrote:
> >On Tue, Jan 12, 2016 at 11:54:59PM +0100, Arnd Bergmann wrote:
> >>On Tuesday 12 January 2016 10:14:18 liviu.dudau@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.
> >
>
> I had tried to modify the drivers/of/address.c to address this problem, but it looks
> not so general. I'm not sure you have seen this: https://lkml.org/lkml/2016/1/10/89 .

Yes, I have seen it. Based on Arnd's suggestion, it is probably the way to go.

Best regards,
Liviu

>
> Regards,
> Rongrong
>

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