RE: [PATCH v2 2/2] dt-bindings: net: adin: Document bindings for fast link down disable

[Ken Sloat]

Hi Krzysztof,

Thanks for your reply and sorry for the late response.

> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Sent: Thursday, March 2, 2023 2:00 AM
> To: Ken Sloat <ken.s@xxxxxxxxxxxxx>
> Cc: noname.nuno@xxxxxxxxx; pabeni@xxxxxxxxxx;
> edumazet@xxxxxxxxxx; Michael Hennerich
> <michael.hennerich@xxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>;
> Jakub Kicinski <kuba@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>;
> Andrew Lunn <andrew@xxxxxxx>; Heiner Kallweit <hkallweit1@xxxxxxxxx>;
> Russell King <linux@xxxxxxxxxxxxxxx>; Alexandru Tachici
> <alexandru.tachici@xxxxxxxxxx>; netdev@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 2/2] dt-bindings: net: adin: Document bindings for
> fast link down disable
> 
> On 28/02/2023 19:49, Ken Sloat wrote:
> > The ADI PHY contains a feature commonly known as "Fast Link Down" and
> > called "Enhanced Link Detection" by ADI. This feature is enabled by
> > default and provides earlier detection of link loss in certain
> > situations.
> >
> 
> Please use scripts/get_maintainers.pl to get a list of necessary people and
> lists to CC.  It might happen, that command when run on an older kernel,
> gives you outdated entries.  Therefore please be sure you base your patches
> on recent Linux kernel.
> 

Understood

> > Document the new optional flags "adi,disable-fast-down-1000base-t" and
> > "adi,disable-fast-down-100base-tx" which disable the "Fast Link Down"
> > feature in the ADI PHY.
> 
> You did not explain why do you need it.

My thoughts were this was explained in the feature patch and so was redundant here which is why I gave a brief summary, but if the norm is to duplicate this information I can certainly do that.

> 
> >
> > Signed-off-by: Ken Sloat <ken.s@xxxxxxxxxxxxx>
> > ---
> 
> Don't attach your new patchsets to your old threads. It buries them deep and
> make usage of our tools difficult.
> 
I added the in-reply-to id in git send-email as I thought this was the norm but I will not do this in the future, sorry.

> 
> >  Documentation/devicetree/bindings/net/adi,adin.yaml | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/net/adi,adin.yaml
> > b/Documentation/devicetree/bindings/net/adi,adin.yaml
> > index 64ec1ec71ccd..923baff26c3e 100644
> > --- a/Documentation/devicetree/bindings/net/adi,adin.yaml
> > +++ b/Documentation/devicetree/bindings/net/adi,adin.yaml
> > @@ -52,6 +52,18 @@ properties:
> >      description: Enable 25MHz reference clock output on CLK25_REF pin.
> >      type: boolean
> >
> > +  adi,disable-fast-down-1000base-t:
> > +    $ref: /schemas/types.yaml#definitions/flag
> > +    description: |
> > +      If set, disables any ADI fast link down ("Enhanced Link Detection")
> > +      function bits for 1000base-t interfaces.
> 
> And why disabling it per board should be a property of DT?
> 
That seemed like a logical place to allow override on boards where it is undesired. Would you say that properties such as this should instead be custom PHY tunables, which may require patching of ethtool as well?

> Best regards,
> Krzysztof

Sincerely,
Ken Sloat