Subject: Re: [PATCH v2 1/3] dt-bindings: i2c: mpc: Add fsl,i2c-erratum-a004447 flag

From: Rob Herring <[email-masked]>
Date: Fri, 7 May 2021 16:49:36 -0500

On Fri, May 07, 2021 at 12:40:45PM +1200, Chris Packham wrote:
> Document the fsl,i2c-erratum-a004447 flag which indicates the presence
> of an i2c erratum on some QorIQ SoCs.
> 
> Signed-off-by: Chris Packham <[email-masked]>
> ---
>  Documentation/devicetree/bindings/i2c/i2c-mpc.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mpc.yaml b/Documentation/devicetree/bindings/i2c/i2c-mpc.yaml
> index 7b553d559c83..98c6fcf7bf26 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mpc.yaml
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mpc.yaml
> @@ -46,6 +46,13 @@ properties:
>      description: |
>        I2C bus timeout in microseconds
>  
> +  fsl,i2c-erratum-a004447:
> +    $ref: /schemas/types.yaml#/definitions/flag
> +    description: |
> +      Indicates the presence of QorIQ erratum A-004447, which
> +      says that the standard i2c recovery scheme mechanism does
> +      not work and an alternate implementation is needed.

The problem with adding a property for an errata is you have to update 
the dtb. If you use the compatible string, then only an OS update is 
needed. That assumes you have specific enough compatible strings.

Rob