Subject: Re: [PATCH net-next v2 1/2] dpll: move fractional-frequency-offset-ppt under pin-parent-device

From: Jiri Pirko <[email-masked]>
Date: Mon, 4 May 2026 10:48:09 +0200

Thu, Apr 30, 2026 at 07:36:10PM +0200, [email-masked] wrote:
>Move the fractional-frequency-offset-ppt attribute from the top-level
>pin attributes into the pin-parent-device nested attribute set. This
>makes it consistent with phase-offset which is already per-parent and
>clarifies that FFO PPT represents the frequency difference between
>a pin and its parent DPLL device.
>
>The top-level fractional-frequency-offset attribute (in PPM) remains
>unchanged for backward compatibility.

That is odd. The ppt one was added just for higher precision but was
semantically the same. Now you change it. Could you still treat both the
same?

>
>Distinguish the two contexts in the ffo_get callback by passing
>dpll=NULL for the top-level (rx vs tx symbol rate) call and a valid
>dpll pointer for the nested (pin vs parent DPLL) call. Update mlx5
>and zl3073x drivers to return -ENODATA for the nested context they
>do not yet support.
>
>Add documentation for both FFO attributes to dpll.rst.
>

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