Re: [PATCH net] net/mlx5: DPLL, fix fractional frequency offset scaling

[Ivan Vecera]

On 10/15/26 09:40, Tariq Toukan wrote:
> From: Carolina Jubran <cjubran@xxxxxxxxxx>
>
> The frequency_diff is reported by firmware in parts-per-trillion, which
> is exactly what the DPLL core now expects from the ffo_get callback.
>
> Commit bc443c253fcd ("dpll: expose fractional frequency offset in ppt")
> switched the callback contract to ppt but assumed frequency_diff was in
> ppm and scaled it by 1000000 to "convert" it. Since the value was
> already ppt, this makes both exported attributes wrong.
>
> Report frequency_diff as is and let the core divide it down for the
> legacy ppm attribute.
>
> Fixes: f035dca34ede ("net/mlx5: DPLL, Implement fractional frequency offset get pin op")
> Signed-off-by: Carolina Jubran <cjubran@xxxxxxxxxx>
> Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
> Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
> ---
It’s a pity we didn’t implement FFO in ppt units right from the start... We
wouldn’t have to carry a duplicate attribute in ppm units now for the sake of
backward compatibility.

Anyway...

Reviewed-by: Ivan Vecera <ivecera@xxxxxxxxxx>