[RFC PATCH 0/1] Categorize ARM dts directory

[Matthias Brugger]

On 25/04/2023 00:23, Ansuel Smith wrote:
> Il giorno mar 25 apr 2023 alle ore 00:10 Rob Herring
> <robh+dt at kernel.org> ha scritto:
>>
>> On Tue, Mar 29, 2022 at 8:27 AM Ansuel Smith <ansuelsmth at gmail.com> wrote:
>>>
>>> On Tue, Mar 29, 2022 at 03:20:18PM +0200, Krzysztof Kozlowski wrote:
>>>> On 28/03/2022 02:09, Ansuel Smith wrote:
>>>>> Hi,
>>>>> as the title say, the intention of this ""series"" is to finally categorize
>>>>> the ARM dts directory in subdirectory for each oem.
>>>>>
>>>>> The main reason for this is that it became unpractical to handle 2600
>>>>> dts files and try to even understand/edit/check the situation for a
>>>>> specific target.
>>>>>
>>>>> In arm64 we already have this kind of separation and I honestly think
>>>>> that this was never proposed for ARM due to the fact that there are
>>>>> 2600+ files to sort and the fact that it will be a mess to merge this
>>>>> entirely but IMHO with a little bit of effort we can finally solve this
>>>>> problem and have a well organized directory just like arm64.
>>>>>
>>>>> Some prerequisite on how this work was done:
>>>>> - This comes entirely from a python script created by me for the task.
>>>>>    linked here [1]
>>>>> - I had to manually categorize all the different arch in the makefile
>>>>>    based on the oem. I searched every arch on the internet trying to
>>>>>    understand the correct oem. I hope they are correct but I would love
>>>>>    some comments about them.
>>>>> - This current ""series"" is all squashed in one big commit to better
>>>>>    receive comments for this. The final version ideally would have all
>>>>>    changes in separate commits. The script can already do this, it's just
>>>>>    commented.
>>>>>
>>>>> Here is a list of some discoveries while doing all the sorting.
>>>>> These are totally additional reason why we need this.
>>>>>
>>>>> While creating the script I discovered some funny things:
>>>>> - We have orphan dts! There are dts that are never compiled and are
>>>>>    there just for reference. We would never have noticed this without this
>>>>>    change and probably nobody noticed it. They are currently all listed
>>>>>    in the python script.
>>>>> - We have dtsi shared across different oem. My current solution for them
>>>>>    is: NOT SORT THEM and leave them in the generic directory and create a
>>>>>    link in each oem dts that points to these dtsi. This is to try in
>>>>>    every way possible to skip any additional changes to the dts.
>>>>>    Current dtsi that suffers from this are only 3. (listed in the script)
>>>>> - arm64 dts and dtsi reference ARM dts. Obviously this change would cause
>>>>>    broken include for these special dtsi. The script creates a dependency
>>>>>    table of the entire arm64 directory and fix every broken dependency
>>>>>    (hoping they all use a sane include logic... regex is used to parse
>>>>>    all the different dependency)
>>>>>
>>>>> So in short the script does the following steps:
>>>>> 1. Enumerate all the action to do... (dts to move, scan dependency for
>>>>>     the dts...)
>>>>> 2. Generate the arm64 dependency
>>>>> 3. Creates the Makefile
>>>>> 4. Generate the Makefiles for the current oem
>>>>> 5. Move all the related dts and dtsi for the current oem
>>>>> 6. Check broken dependency and fix them by editing the dts and writing
>>>>>     the correct include (or fix any symbolic link)
>>>>>
>>>>> This is an output that describes all the things done by the script [2]
>>>>>
>>>>> I really hope I didn't commit any logic mistake in the script but most
>>>>> of the work should be done.
>>>>>
>>>>
>>>> +Cc Arnd and Olof,
>>>>
>>>> Ansuel,
>>>> Thanks for you patch. Please cc the SoC maintainers in such submissions.
>>>> It seems that you got some quite nice discussion, but still the core
>>>> folks are not Cced, so no one would be able to take your patch...
>>>>
>>>
>>> I had some problem with gmail and sending mail too much users. I put Rob
>>> and You and all the various list to try to workaround the "gmail spam
>>> protection"
>>>
>>>> I am pretty sure we were discussing such split idea in the past and it
>>>> did not get traction, but I cannot recall the exact discussion.
>>>>
>>>
>>> I think the main issue here is how to handle bot and how problematic is
>>> to merge this. As written in the cover letter the final version of this
>>> should be a big series of 50+ patch with every commit specific to each
>>> oem. In theory we should be able to merge the different oem separately
>>> and try to at least start the categorization.
>>> Another idea I got to at least have a "migration path" is to convert
>>> every dts in the dts/ directory to a symbolic link that target the dts
>>> in the correct oem. But I assume that would fix only part of the problem
>>> and git am will still be problematic.
>>
>> I have a script[1] that does the conversion written the last time this
>> came up. Just have to agree on directory names. I think the easiest
>> would be for Arnd/Olof to run it at the end of a merge window before
>> rc1.
>>
>> I'm very much in favor of this happening especially before *any*
>> overlays are added to add to the mess (it's probably already
>> happened).
>>
>> Rob
>>
>> [1] https://lore.kernel.org/all/20181204183649.GA5716@bogus/
> 
> Hi Rob,
> thanks for recovering this. I remember also providing a script.
> 
> Anyway considering the amount of stuff to move, I feel like some
> OEM might be problematic to move due to rebase and merging problems.
> 
> We should consider accepting moving only some and keep other
> in the unsorted path. And move them at the first time possible with
> the help of the maintainers.
> 
> One main blocker of this is some qcom dts that are linked to arm64
> directory, so for some dts special care is needed.
> 

Same happens for broadcom RaspberryPi DTS. The arm64 ones include the arm ones.

Regards,
Matthias