Re: [PATCH net-next] net: dsa: bcm_sf2: Ensure that MDIO diversion is used

From: Andrew Lunn
Date: Fri Sep 04 2020 - 10:14:28 EST


On Thu, Sep 03, 2020 at 09:00:13PM -0700, Florian Fainelli wrote:
>
>
> On 9/3/2020 3:03 PM, Andrew Lunn wrote:
> > > The firmware provides the Device Tree but here is the relevant section for
> > > you pasted below. The problematic device is a particular revision of the
> > > silicon (D0) which got later fixed (E0) however the Device Tree was created
> > > after the fixed platform, not the problematic one. Both revisions of the
> > > silicon are in production.
> > >
> > > There should have been an internal MDIO bus created for that chip revision
> > > such that we could have correctly parented phy@0 (bcm53125 below) as child
> > > node of the internal MDIO bus, but you have to realize that this was done
> > > back in 2014 when DSA was barely revived as an active subsystem. The
> > > BCM53125 node should have have been converted to an actual switch node at
> > > some point, I use a mdio_boardinfo overlay downstream to support the switch
> > > as a proper b53/DSA switch, anyway.
> >
> > I was expecting something like that. I think this patch needs a
> > comment in the code explaining it is a workaround for a DT blob which
> > cannot be changed. Maybe also make it conditional on the board
> > compatible string?
>
> It is already targeted at the Broadcom pseudo PHY address (30) which is the
> one that needs diversion, I will update the patch description accordingly
> though.

O.K, looking at the patch, it was not clear to me it was already
restricted.

Andrew