Re: [PATCH net-next 3/3] net: stmmac: Add glue layer for Spacemit K3 SoC

Andrew Lunn
2026-01-21T01:29:58Z

On Wed, Jan 21, 2026 at 06:36:01AM +0800, Inochi Amaoto wrote:
> On Tue, Jan 20, 2026 at 02:56:26PM +0100, Andrew Lunn wrote:
> > > +/* Note: the delay step value is at 0.1ps */
> > > +static const unsigned int k3_delay_step_10x[4] = {
> > > + 367, 493, 559, 685
> > > +};
> >
> > Am i reading it correctly that RGMII delays are limited to these four
> > values?
> >
> > If so, please add this list to the DT binding.
> >
>
> No, these value are just adjustment interval, and it is also
> controlled by another code register, the final delay is calculated
> by the following formula:
>
> delay = delay_step * delay_code * 0.9;
>
> So the delay configuration needs to be calculated instead of
> directly assigned.

O.K.

So what is the actual range? Can is do 1000ps? 2000ps? 3000ps? Should
there be a basic range check to avoid dumb typos?

Andrew