Re: [PATCH v1 2/2] dt-bindings: mmc: mtk-sd: add 64-steps tuning related property

[Axe Yang (杨磊)]

Hi Krzysztof,

Thank you for the comments. I uploaded patchset v2 just now, please
have a look.

Regards,
Axe

On Fri, 2023-11-24 at 09:24 +0100, Krzysztof Kozlowski wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On 24/11/2023 08:08, Axe Yang wrote:
> > Add 'mediatek,tune-64-steps' option. This property will give MSDC
> > a chance to achieve a more optimal calibration result, thus
> avoiding
> > potential CRC issues.
> 
> Documentation goes before users.

Fixed in v2.

> > 
> > Signed-off-by: Axe Yang <axe.yang@xxxxxxxxxxxx>
> > ---
> >  Documentation/devicetree/bindings/mmc/mtk-sd.yaml | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > index 3fffa467e4e1..c33301e2ea33 100644
> > --- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > @@ -145,6 +145,14 @@ properties:
> >      minimum: 0
> >      maximum: 7
> >  
> > +  mediatek,tune-64-steps:
> > +    $ref: /schemas/types.yaml#/definitions/flag
> > +    description:
> > +      Some Soc need enable 64-steps tuning for better delay value
> to avoid CRC issue.
> 
> This scales poorly. Instead should be enum with number of tuning
> steps.

Fixed in v2.

> 
> > +      If present, tune 64 steps to cover a complete clock cycle.
> > +      If not present, tune only 32 steps. For eMMC and SD, this
> can also yield
> > +      satisfactory calibration results in most cases.
> 
> Best regards,
> Krzysztof
>