Some Samsung Exynos boards using the arm64 architecture have DW MMC
controllers configured for a 32-bit data bus but a 64-bit FIFO. On these
systems the 64-bit FIFO registers must be accessed in two 32-bit halves.
---
 .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml   | 7 +++++++
 1 file changed, 7 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..d025b38ca 100644
--- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
+++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
@@ -57,6 +57,13 @@ properties:
       force fifo watermark setting accordingly.
     $ref: /schemas/types.yaml#/definitions/flag
 
+  fifo-access-32bit:
+    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.
+    $ref: /schemas/types.yaml#/definitions/flag
+
   dmas:
     maxItems: 1
 
-- 
2.38.3

On 11/03/2023 19:15, Sergey Lisov wrote:
> Some Samsung Exynos boards using the arm64 architecture have DW MMC
> controllers configured for a 32-bit data bus but a 64-bit FIFO. On these
> systems the 64-bit FIFO registers must be accessed in two 32-bit halves.
> ---
>  .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml   | 7 +++++++
>  1 file changed, 7 insertions(+)

Missing changelog (I did not get cover letter, so no changelog there
either).

> diff --git a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> index 8dfad89c7..d025b38ca 100644
> --- a/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> +++ b/Documentation/devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml
> @@ -57,6 +57,13 @@ properties:
>        force fifo watermark setting accordingly.
>      $ref: /schemas/types.yaml#/definitions/flag
>  
> +  fifo-access-32bit:
> +    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.
> +    $ref: /schemas/types.yaml#/definitions/flag

Anyway, I said last time this looks compatible-specific, so I don't
think we need another property.

Best regards,
Krzysztof

> 
> Missing changelog (I did not get cover letter, so no changelog there
> either).
> 

Got it, will fix in the next revision.

> 
> Anyway, I said last time this looks compatible-specific, so I don't
> think we need another property.
> 
> Best regards,
> Krzysztof

I agree, but I'm afraid of introducing regressions by enabling this
workaround on systems that don't actually need it.

On 12/03/2023 11:18, Krzysztof Kozlowski wrote:
> On 11/03/2023 19:15, Sergey Lisov wrote:
>> Some Samsung Exynos boards using the arm64 architecture have DW MMC
>> controllers configured for a 32-bit data bus but a 64-bit FIFO. On these
>> systems the 64-bit FIFO registers must be accessed in two 32-bit halves.
>> ---
>>  .../devicetree/bindings/mmc/synopsys-dw-mshc-common.yaml   | 7 +++++++
>>  1 file changed, 7 insertions(+)
> 
> Missing changelog (I did not get cover letter, so no changelog there
> either).

Correction: I see the cover letter, but anyway without changelog :)


Best regards,
Krzysztof