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

From: Krzysztof Kozlowski

Date: Sat Apr 11 2026 - 16:27:50 EST


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.

Best regards,
Krzysztof