Re: [PATCH net-next] dpll: zl3073x: Allow to use custom phase measure averaging factor

[Przemek Kitszel <przemyslaw.kitszel@intel.com>]

On 9/10/25 12:32, Ivan Vecera wrote:
> The DPLL phase measurement block uses an exponential moving average,
> calculated using the following equation:
> 
>                         2^N - 1                1
> curr_avg = prev_avg * --------- + new_val * -----
>                           2^N                 2^N
> 
> Where curr_avg is phase offset reported by the firmware to the driver,
> prev_avg is previous averaged value and new_val is currently measured
> value for particular reference.
> 
> New measurements are taken approximately 40 Hz or at the frequency of
> the reference (whichever is lower).
> 
> The driver currently uses the averaging factor N=2 which prioritizes
> a fast response time to track dynamic changes in the phase. But for
> applications requiring a very stable and precise reading of the average
> phase offset, and where rapid changes are not expected, a higher factor
> would be appropriate.
> 
> Add devlink device parameter phase_offset_avg_factor to allow a user
> set tune the averaging factor via devlink interface.
> 
> Tested-by: Prathosh Satish <Prathosh.Satish@microchip.com>
> Signed-off-by: Ivan Vecera <ivecera@redhat.com>
> ---
>   Documentation/networking/devlink/zl3073x.rst |  4 ++
>   drivers/dpll/zl3073x/core.c                  |  6 +-
>   drivers/dpll/zl3073x/core.h                  |  8 ++-
>   drivers/dpll/zl3073x/devlink.c               | 67 ++++++++++++++++++++
>   4 files changed, 82 insertions(+), 3 deletions(-)
> 

looks good,
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>

> +static int
> +zl3073x_devlink_param_phase_avg_factor_validate(struct devlink *devlink, u32 id,
> +						union devlink_param_value val,
> +						struct netlink_ext_ack *extack)
> +{
> +	return (val.vu8 < 16) ? 0 : -EINVAL;

nit: redundant params, not worth respining