Re: [PATCH 1/2] dt-bindings: mmc: dw-mshc-common: add option for configuring DMA threshold

[Kaustabh Chakraborty]

On 2026-04-11 22:27 +02:00, Krzysztof Kozlowski wrote:
> On 11/04/2026 21:43, Kaustabh Chakraborty wrote:
>> Some controllers, such as certain Exynos SDIO ones, are unable to
>> perform DMA transfers of small amount of bytes properly. Add a property
>> to configure the DMA transfer threshold.
>> 
>> Signed-off-by: Kaustabh Chakraborty <kauschluss@xxxxxxxxxxx>
>> ---
>>  .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml          | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
>> index 6f11b2adf1036..1693277957a91 100644
>> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
>> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
>> @@ -57,6 +57,14 @@ properties:
>>        force fifo watermark setting accordingly.
>>      $ref: /schemas/types.yaml#/definitions/flag
>>  
>> +  dma-threshold-bytes:
>> +    description:
>> +      DMA transfer takes place only if the transfer size is equal to or greater
>> +      than the number of bytes defined by the threshold value. Some controllers are
>> +      unable to perform the DMA transfer properly with small amounts of data.
>
> Looks like controller specific, thus should be deducible from the
> compatible.

"samsung,dma-threshold-bytes"? So you also suggest I move it to the
Samsung's schema? Okay.

>
> Best regards,
> Krzysztof