[U-Boot] [PATCH v3 14/16] tegra: dts: Add serial port details

[Simon Glass]

Hi Stephen,

On 4 August 2014 11:47, Stephen Warren <swarren at wwwdotorg.org> wrote:
>
> On 08/04/2014 04:43 AM, Simon Glass wrote:
>>
>> On 1 August 2014 15:50, Stephen Warren <swarren at wwwdotorg.org> wrote:
>
> ...
>
>>> DT schemas/bindings MUST be identical between U-Boot, Linux, FreeBSD,
>>> Barebox, ... (all of which use DT). As such, all the DT bindings MUST be
>>> discussed on the devicetree mailing list.
>>>
>>> Since you're the author of the patch, it's your responsibility to have that
>>> discussion.
>>
>>
>> Are you referring to the linux,stdout-path discussion, or something
>> more DT-generic?I suppose we could have a 'u-boot,console' for our
>> part. But in any case you are talking about code and a convention that
>> is already in mainline U-Boot.
>
>
> I'm saying that any and all additions or changes to DT schemas/bindings must be discussed on the devicetree mailing list, not made/reviewed in isolation on only the U-Boot mailing list.
>
>
> > While I accept that we might change to
>>
>> something DT-generic if Linux points the way to something better, I
>> don't want to stop using it just because Linux hasn't decided yet. The
>> early console stuff and early debug UART stuff in Linux is not yet a
>> shining example of perfection.
>
>
> I strongly believe that if U-Boot continues to use DT, the current DT usage in U-Boot needs to be actively moved in line with the bindings that the Linux kernel, Barebox, FreeBSD, ... use. I'd prefer this to happen even before U-Boot starts making additional use of DT, so the conversion doesn't get forgotten. However, I suppose it's a bit draconian to prevent further usage until the existing usage is cleaned up, except where new usage introduces additional dependencies on any current usage that's inconsistent with the standard bindings.
>
>
>> That said, it's a good time to adopt 'u-boot,console' if that's what we need?
>
>
> It's certainly a good time to start that discussion on the devicetree mailing list, and get such a new property reviewed/ack'd there.

[side note: You will be aware that I have expended considerable effort
getting agreement on bindings. I used to copy all DT patches to that
mailing list, but I can't recall getting a reply that often. Also note
that U-Boot's use of DT pre-dated the kernel with many subsystems
(e.g. the request to retrofit clock bindings after the code was
already written). Yes, DT bindings should be common across all
platforms, but where subsystems don't exist in U-Boot I feel the
approach of 'do nothing until someone writes a new subsystem' might
just be a recipe for inaction/no progress. Better to iterate towards
perfection than never move]

So to be clear, with the clock-frequency property moved back to being
hard-coded in the CONFIG, your remaining objection is that the console
alias, which is already used in U-Boot, should be agreed with the
devicetree mailing list? Is that right?

Regards,
Simon