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Date: Fri, 22 Jun 2012 10:20:00 -0600
From: Stephen Warren <swarren@wwwdotorg.org>
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To: Thierry Reding <thierry.reding@avionic-design.de>
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Subject: Re: [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support
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On 06/21/2012 12:47 AM, Thierry Reding wrote:
...
> Everybody seems to be happy with this approach, so I'll give it a
> shot. There is one thing I'm still unsure about, though. What if
> somebody uses the above scheme and maps the registers to the wrong
> port. The same goes for the nvidia,ctrl-offset property. It needs
> to match the register offset because they are directly related. I
> suppose we could leave that property away and look up the register
> via the port index (which, as Stephen already said, we'll have to
> do in other places anyway, unless we list all bit positions in the
> DT).
> 
> Can we safely ignore such issues and assume the device tree to
> always be right? Should we just not care if somebody uses it
> wrongly?

I think that's pretty much the same thing as plain putting the wrong
reg property into any node - the value is wrong, so it doesn't work.
There's not too much you can do about it.

I'd be happy to remove the nvidia,ctrl-offset property to avoid the
need to specify basically the same information multiple times though;
nothing wrong with making it easier to write the correct DT content.