Re: [PATCH net-next v3 3/5] net: pcs: add new PCS driver for altera TSE PCS

[Andrew Lunn]

> > > +	/* This PCS seems to require a soft reset to re-sync the
> > > AN logic */
> > > +	tse_pcs_reset(tse_pcs);  
> > 
> > This is kinda strange since c22 phys are supposed to reset the other
> > registers to default values when BMCR_RESET is written. Good thing
> > this is a PCS...
> 
> Indeed. This soft reset will not affect the register configuration, it
> will only reset all internal state machines.
> 
> The datasheet actually recommends performing a reset after any
> configuration change...

The Marvell PHYs work like this. Many of its registers won't take
effect until you do a soft reset. I think the thinking behind this is
that changing many registers is disruptive to the link and slow. It
takes over a second to perform auto-neg etc. So ideally you want to
make all your register changes, and then trigger them into operation.
And a soft reset is this trigger.

    Andrew