Re: [PATCH net-next v2 1/6] dpll: zl3073x: Store raw register values instead of parsed state

[Vadim Fedorenko]

On 12/11/2025 19:24, Ivan Vecera wrote:
> On 11/12/25 3:12 PM, Vadim Fedorenko wrote:
> > On 11/11/2025 18:12, Ivan Vecera wrote:
> > > The zl3073x_ref, zl3073x_out and zl3073x_synth structures
> > > previously stored state that was parsed from register reads. This
> > > included values like boolean 'enabled' flags, synthesizer selections,
> > > and pre-calculated frequencies.
> > >
> > > This commit refactors the state management to store the raw register
> > > values directly in these structures. The various inline helper functions
> > > are updated to parse these raw values on-demand using FIELD_GET.
> > >
> > > Reviewed-by: Petr Oros <poros@xxxxxxxxxx>
> > > Tested-by: Prathosh Satish <Prathosh.Satish@xxxxxxxxxxxxx>
> > > Signed-off-by: Ivan Vecera <ivecera@xxxxxxxxxx>
> > > ---
> > >   drivers/dpll/zl3073x/core.c | 81 ++++++++++++-------------------------
> > >   drivers/dpll/zl3073x/core.h | 61 ++++++++++++++++------------
> > >   2 files changed, 60 insertions(+), 82 deletions(-)
> > >
> > > diff --git a/drivers/dpll/zl3073x/core.c b/drivers/dpll/zl3073x/core.c
> > > index e42e527813cf8..50c1fe59bc7f0 100644
> > > --- a/drivers/dpll/zl3073x/core.c
> > > +++ b/drivers/dpll/zl3073x/core.c
> > > @@ -598,25 +598,22 @@ int zl3073x_write_hwreg_seq(struct zl3073x_dev 
> > > *zldev,
> > >    * @zldev: pointer to zl3073x_dev structure
> > >    * @index: input reference index to fetch state for
> > >    *
> > > - * Function fetches information for the given input reference that are
> > > - * invariant and stores them for later use.
> > > + * Function fetches state for the given input reference and stores 
> > > it for
> > > + * later user.
> > >    *
> > >    * Return: 0 on success, <0 on error
> > >    */
> > >   static int
> > >   zl3073x_ref_state_fetch(struct zl3073x_dev *zldev, u8 index)
> > >   {
> > > -    struct zl3073x_ref *input = &zldev->ref[index];
> > > -    u8 ref_config;
> > > +    struct zl3073x_ref *ref = &zldev->ref[index];
> > >       int rc;
> > >       /* If the input is differential then the configuration for N-pin
> > >        * reference is ignored and P-pin config is used for both.
> > >        */
> > > -    if (zl3073x_is_n_pin(index) &&
> > > -        zl3073x_ref_is_diff(zldev, index - 1)) {
> > > -        input->enabled = zl3073x_ref_is_enabled(zldev, index - 1);
> > > -        input->diff = true;
> > > +    if (zl3073x_is_n_pin(index) && zl3073x_ref_is_diff(zldev, index 
> > > - 1)) {
> > > +        memcpy(ref, &zldev->ref[index - 1], sizeof(*ref));
> >
> > Oh, it's not obvious from the code that it's actually safe, unless
> > reviewer remembers that N-pins have only even indexes.
>
> Would it be helpful to add here the comment describing that is safe and
> why?

Yes, comment would be great to have.

> > Have you thought of adding an abstraction for differential pair pins?
>
> No, zl3073x_ref represents mailbox for HW reference... Here, I’m just
> following the datasheet, which states: "If the P-pin is marked as
> differential then some content of the mailbox for N-pin is ignored and
> is inherited from the P-pin".
> For now, the content of zl3073x_ref is the inherited one, but this may
> change in the future.
>
> The abstraction for differential pin pairs is actually handled in
> dpll.c, where only a single dpll_pin is registered for each such pair.
>
> Ivan