Re: [PATCH V3 4/4] arm64: dts: qcom: sm8550: Remove SDR104/SDR50 broken capabilities

[Krzysztof Kozlowski <krzk@kernel.org>]

On 18/06/2025 10:44, Sarthak Garg wrote:
> 
> 
> On 6/18/2025 1:11 PM, Krzysztof Kozlowski wrote:
>> On 18/06/2025 09:28, Sarthak Garg wrote:
>>> Kernel now handles all level shifter limitations related to SD card
>>> modes.
>>> As a result, the broken hardware capabilities for SDR104 and SDR50 modes
>>> can be removed from the device tree.
>>> Additionally, due to level shifter constraints, set the maximum
>>> frequency for High Speed (HS) mode to 37.5 MHz using the
>>> max-sd-hs-frequency property for sm8550.
>>>
>>> Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
>>> ---
>>>   arch/arm64/boot/dts/qcom/sm8550.dtsi | 4 +---
>>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/sm8550.dtsi b/arch/arm64/boot/dts/qcom/sm8550.dtsi
>>> index 82cabf777cd2..2c770c979d39 100644
>>> --- a/arch/arm64/boot/dts/qcom/sm8550.dtsi
>>> +++ b/arch/arm64/boot/dts/qcom/sm8550.dtsi
>>> @@ -3180,6 +3180,7 @@ sdhc_2: mmc@8804000 {
>>>   			iommus = <&apps_smmu 0x540 0>;
>>>   			qcom,dll-config = <0x0007642c>;
>>>   			qcom,ddr-config = <0x80040868>;
>>> +			max-sd-hs-frequency = <37500000>;
>> So my previous comments stay... This is SoC thus deducible from compatible.
>>
>> Best regards,
>> Krzysztof
> 
> " I agree that a DT property for the mmc controller would make sense.
> 
> Although, this seems limited to SD UHS-I speed modes, so perhaps
> "max-sd-uhs-frequency" would be a better name for it?
> 
> Kind regards
> Uffe "
> 
> https://patchwork.kernel.org/project/linux-mmc/cover/20250523105745.6210-1-quic_sartgarg@quicinc.com/
> 
> This was the comment given on V2 to introduce a generic dt
> property.


I know, it does not matter. If this is here, it is a 100% proof this is
SoC specific, thus you have compatible for that.

Best regards,
Krzysztof