Re: [PATCH net-next 1/3] net: dsa: yt921x: Refactor long register helpers

[David Yang]

On Wed, Feb 25, 2026 at 9:52 PM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> > -/* Some registers, like VLANn_CTRL, should always be written in 64-bit, even if
> > - * you are to write only the lower / upper 32 bits.
> > +/* Some registers, like VLANn_CTRL, should always be written in chunks, even if
> > + * you only want to write parts of 32 bits.
> >   *
> > - * There is no such restriction for reading, but we still provide 64-bit read
> > - * wrappers so that we always handle u64 values.
> > + * There is no such restriction for reading, but we still provide multi-chunk
> > + * read wrappers so that we can handle them consistently.
> >   */
> >
> > -static int yt921x_reg64_read(struct yt921x_priv *priv, u32 reg, u64 *valp)
> > +static int
> > +yt921x_longreg_read(struct yt921x_priv *priv, u32 reg, u32 *vals,
> > +                 unsigned int span)
>
> Just looking at this, it is not obvious what units span is. Many bulk
> read operations takes bytes, even if the underlying code works in
> words. I would probably rename span to something like num_u32.
>
> I would also keep yt921x_reg64_read, yt921x_reg64_write,
> yt921x_reg64_update_bits() and just makes them wrappers which call
> yt921x_longreg_read().
>

I don't think keeping reg64_* would make it better. There will be more
96-bit regs as subsequent series progressing. It would be more messy
to have three types of regs: u32, u64, and u32[].