Re: [PATCH 1/2] devicetree: synopsys-dw-mshc-common: add "fifo-access-32bit" property

[Krzysztof Kozlowski]

On 11/03/2023 16:22, Sergey Lisov wrote:

Use subject prefixes matching the subsystem (which you can get for
example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
your patch is touching).

Missing commit msg, which should answer why you are doing this and give
more background.

> ---
>  .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml    | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> index 8dfad89c7..2bc5ac528 100644
> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> @@ -57,6 +57,12 @@ properties:
>        force fifo watermark setting accordingly.
>      $ref: /schemas/types.yaml#/definitions/flag
>  
> +  fifo-access-32bit:

Missing type boolean.

> +    description:
> +      Specifies that this device requires accesses to its 64-bit registers
> +      to be done as pairs of 32-bit accesses, even on architectures where
> +      readq is available.

And why the device would require this? If it has 64-bit registers in the
first place, they can be accessed in 64-bit. Otherwise these are not
64-bit registers, but just lower/upper 32-bit, right?

Also, why this cannot be implied from compatible? Why different boards
with same SoC should have different FIFO access?



Best regards,
Krzysztof