Re: [PATCH V5 4/4] arm64: dts: qcom: sm8550: Add max-sd-hs-hz property

[Krzysztof Kozlowski <krzk@kernel.org>]

On 04/09/2025 10:36, Konrad Dybcio wrote:
> On 9/3/25 10:21 AM, 'Krzysztof Kozlowski' via kernel wrote:
>> On 03/09/2025 10:04, Sarthak Garg wrote:
>>> Due to board-specific hardware constraints particularly related
>>> to level shifter in this case the maximum frequency for SD High-Speed
>>> (HS) mode must be limited to 37.5 MHz to ensure reliable operation of SD
>>> card in HS mode.
>>>
>>> This is achieved by introducing the `max-sd-hs-hz` property in the
>>> device tree, allowing the controller to operate within safe frequency
>>> limits for HS mode.
>>>
>>
>> Probably we will now replicate the same discussion... And it will be
>> happening every time you send the same and not reflect it in commit msg.
>>
>> Bindings say board setup, this commit msg says board config, but the
>> patch says SoC. This is not correct.
> 
> Both are correct, looking at the problem from two perspectives.
> 
> The bindings description mentions board-specific limitations (e.g. because
> "the board's electrical design does not allow one to achieve the full rated
> frequency that the SoC can otherwise do, in a stable way")
> 
> Here the author tries to argue that almost all SM8550 boards are broken
> in this sense, because the reference design did not feature the required
> passive components, making most (derivative) designs sort of "broken by
> default" - and only some (if any?) vendors decided to go with the
> additional components required to lift this limitation.
> 
> This in turn makes it fair to assume the developer experience would benefit
> from having the SD card high speed modes always work (with the slight speed
> cap which may not be required for the 1 or 2 designs that took the extra
> step) without each board DT creator having to track down this property
> separately.

And then if you send same v3, I will ask the same. Can the author
finally write commit msgs reflecting discussions and previous disagreements?

Reviewers questions happen for a reason, so sending the same means
person ignored that reason.

Best regards,
Krzysztof