[U-Boot] [PATCH v5 10/13] tegra: Use a U-Boot-specific .dtsi file

[Simon Glass]

Hi Stephen,

On 29 November 2016 at 21:09, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 11/28/2016 03:09 PM, Simon Glass wrote:
>>
>> Hi Stephen,
>>
>> On 17 November 2016 at 12:45, Stephen Warren <swarren at wwwdotorg.org>
>> wrote:
>>>
>>>
>>> On 11/16/2016 06:13 PM, Simon Glass wrote:
>>>>
>>>>
>>>> With the new device-tree rules it is possible to put device-tree changes
>>>> needed by U-Boot into their own file. As an example of this approach,
>>>> move
>>>> Tegra over to use it.
>>>
>>>
>>>
>>> Sounds like a good idea.
>>>
>>>> diff --git a/arch/arm/dts/tegra20-u-boot.dtsi
>>>> b/arch/arm/dts/tegra20-u-boot.dtsi
>
>
>>> I'd expect to see more "U-Boot overlay" DTs than this; I recall there
>>> being more differences between U-Boot and kernel DTS files when I last
>>> sync'd the two.
>>
>>
>> Yes but most of those changes should be dropped. I did a partial sync
>> a few months back but if you recall there were still differences. Is
>> this something the Tegra maintainer might look at?
>>
>> I don't want to immortalise those differences in a separate U-Boot
>> file when really we should just get rid of them.
>
>
> From my perspective, we should have two files:
>
> 1) The base DT.
>
> This should not contain any U-Boot modifications, and should exactly match
> the DT used elsewhere, such as in mainline Linux. Since this should always
> match other DTs, we should pretty much always be able to over-write it with
> any updated DT from other sources.
>
> 2) The U-Boot modifications.
>
> This always contain /all/ local modifications applied by U-Boot. It
> shouldn't matter why the change was made, or how long we hope/expect the
> delta to continue to exist. This will isolate all U-Boot changes into this
> file so it's obvious what local changes exist. If some changes are intended
> to be temporary, we can add a comment to that effect, and eventually submit
> a patch to remove the delta.
>
> I don't think that putting a change into this "U-Boot local overlay" should
> in any way imply that the change is by definition correct and long-term;
> some changes may satisfy that decription and others won't. Just like we
> sometimes have C code that we wish we didn't and eventually clean up.

That's fine with me. What do you want to do with this patch?

Regards,
Simon