[PATCH v2 3/5] dt-bindings: memory: additional compatible strings for Broadcom DPFE

[Krzysztof Kozlowski]

On 01/02/2024 23:36, Markus Mayer wrote:
> On Tue, 23 Jan 2024 at 13:27, Krzysztof Kozlowski
> <krzysztof.kozlowski at linaro.org> wrote:
>>
>> On 19/01/2024 22:52, Markus Mayer wrote:
>>> Add versioned compatible strings for Broadcom DPFE. These take the form
>>> brcm,dpfe-cpu-v<N> where <N> is a number from 1 to 4.
>>>
>>> The chip-specific strings have been kept for compatibility purposes
>>> (hardware is in the field). For new chips, the properly versioned
>>> compatible string should be used.
>>>
>>> Signed-off-by: Markus Mayer <mmayer at broadcom.com>
>>> ---
>>>  .../memory-controllers/brcm,dpfe-cpu.yaml     | 21 ++++++++++++++++++-
>>>  1 file changed, 20 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/memory-controllers/brcm,dpfe-cpu.yaml b/Documentation/devicetree/bindings/memory-controllers/brcm,dpfe-cpu.yaml
>>> index 3f00bc2fd3ec..42c8160d95d1 100644
>>> --- a/Documentation/devicetree/bindings/memory-controllers/brcm,dpfe-cpu.yaml
>>> +++ b/Documentation/devicetree/bindings/memory-controllers/brcm,dpfe-cpu.yaml
>>> @@ -10,9 +10,28 @@ maintainers:
>>>    - Krzysztof Kozlowski <krzk at kernel.org>
>>>    - Markus Mayer <mmayer at broadcom.com>
>>>
>>> +description: |
>>> +
>>
>> Drop blank line.
> 
> Will do.
> 
>>> +  The DCPU (DDR PHY Front End CPU) interfaces directly with the DDR PHY
>>> +  chip on Broadcom STB SoCs. An API exists for other agents to retrieve
>>> +  or set certain DDR PHY chip parameters by JEDEC.
>>> +
>>> +  Different, incompatible versions of this API have been created over
>>> +  time. The API has changed for the some chips as development progressed
>>> +  and features were added or changed.
>>> +
>>> +  We rely on the boot firmware (which already knows the API version
>>> +  required) to populate Device Tree with the corresponding compatible
>>> +  string.
>>> +
>>>  properties:
>>>    compatible:
>>>      items:
>>> +      - enum:
>>> +          - brcm,dpfe-cpu-v1
>>> +          - brcm,dpfe-cpu-v2
>>> +          - brcm,dpfe-cpu-v3
>>> +          - brcm,dpfe-cpu-v4
>>
>> I don't see my comment resolved - except more unusual order of
>> compatibles - and nothing in commit msg explains my previous concerns.
> 
> I am confused. What about ordering them in alphabetically ascending
> order is unusual?

Order of entire list - you just added everything to the beginning of the
list. This does not make sense.

> 
> Which concerns, specifically, are you referencing? I promise I am not

That you claim here that bcm7271 is both v1, v2, v3 and v4. Nothing in
the commit msg explains this.

Nothing from my message here:
https://lore.kernel.org/all/3fff866f-fbe8-4d23-87f3-275380adf3d4@linaro.org/
is resolved or addressed.


> deliberately ignoring concerns as there would be no point in doing so.
> I have nothing to gain from it. I am trying to get code accepted into
> the kernel. I am not trying to "win any battles" or "prove that I can
> be more stubborn" or anything of that nature. If it is possible to
> integrate concerns raised by the maintainer, I will gladly do so. And
> if not, I'd like to find a way that works for both sides.
> 
> BTW, I once used to be on the Linaro Landing Team for Broadcom. You'll
> find some commits from me in the kernel that carry a linaro.org e-mail
> address. Most are from over a decade ago. Yikes, time flies!
> 
> The reason I am mentioning this is to point out that
> 
> * I am not new to this.
> * I am respecting the Open Source community and so is the rest of the team.
> * We are trying to do the right thing and be "good citizens".
> * We upstream whatever we can to the relevant project, not just the kernel.
> * We aren't on some kind of power-trip or unwilling to listen to feedback.

OK, I see you sent the almost same patch with no improvements in the
code and in commit msg, so that was the assumption. I made quite clear
concerns last time and asked several questions.

> 
> I am not saying this because I think any of the above makes me special
> or particularly accomplished. However, I do think that some things may
> need to be clarified as there does seem to be a certain attitude at
> play here, with certain assumptions, that is far from constructive.
> Hopefully, this has now been cleared up, and we can move forward with
> addressing the outstanding concerns regarding our DPFE compatible
> strings.
> 
>> I think my final comment was pretty clear yet ignored completely. There
>> was no follow up:
>> https://lore.kernel.org/all/3fff866f-fbe8-4d23-87f3-275380adf3d4@linaro.org/
> 
> Unfortunately, it may not be as clear as you think. I did my best to
> incorporate what I thought you meant. Clearly that didn't work out so
> well.
> 
> So, please clarify in more detail, and maybe showing some examples,
> what it is you would like to see. For instance, I have no idea what
> "(e.g. bcm7271 + v1 + generic fallback)" is actually supposed to mean.

This means: List of three compatibles, SoC specific, your versioned one,
generic compatible used as fallback.

> Is that shorthand for 3 compatible strings (brcm,bcm7271-dpfe-cpu,
> brcm,dpfe-cpu-v1, brcm,dpfe-cpu). If so, how is that different from
> what we already had?

If something is unclear in that message, please continue that message.
There was no further explanation, no further comments on my email, so I
assume you agree or understand it.

> 
>> so with ignored comments: NAK

Also - missing device prefix in subject:

Please use subject prefixes matching the subsystem. You can get them for
example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
your patch is touching.


Best regards,
Krzysztof