Re: [PATCH net-next v1 1/2] net: dsa: mv88e6xxx: Default CMODE to 1000BaseX only on 6390X

[Marek Behun <marek.behun@nic.cz>]

On Thu, 24 Jan 2019 11:27:54 -0800
Florian Fainelli <f.fainelli@gmail.com> wrote:

> On 1/24/19 11:24 AM, Marek Behun wrote:
> > On Thu, 24 Jan 2019 19:11:59 +0100
> > Andrew Lunn <andrew@lunn.ch> wrote:
> >   
> >> On Thu, Jan 24, 2019 at 07:04:51PM +0100, Marek Behun wrote:  
> >>> What properties does the cpu port node need to contain to force
> >>> it? phy-mode = "2500base-x"; is not enough.    
> >>
> >> Hi Marek
> >>
> >> For DSA ports we have:
> >>
> >>                                                 phy-mode =
> >> "rgmii-txid"; fixed-link {
> >>                                                         speed =
> >> <1000>; full-duplex;
> >>                                                 };
> >>
> >> See dsa_port_fixed_link_register_of()
> >>
> >>     Andrew  
> > 
> > Hi Andrew,
> > the configuration
> >   phy-mode = "2500base-x";
> >   fixed-link {
> >     speed = <2500>;
> >     full-duplex;
> >   };
> > does not work, because swphy does not support speed=2500 (only 10,
> > 100 and 1000).
> >   managed = "in-band-status";
> > does not work either.
> > 
> > If I use speed = <1000>, then the swphy is created correctly, cmode
> > is set correctly to 2500base-x, but speed register on the port is
> > set to 1000, and the connection does not work.
> > 
> > The easiest way would probably be to implement swphy to support
> > speed 2500. But I don't know what values should the simulated PHY
> > registers contain...
> > 
> > The function dsa_port_fixed_link_register_of creates this phy
> > device, adjusts the link and then calls
> > put_device(&phydev->mdio.dev); Does this mean that the phy device
> > is immediately destroyed?  
> 
> Yes, we should actually migrate that code over to PHYLINK, because in
> PHYLINK the fixed links don't require creating a phy_device instance.
> This is something that has a potential of breaking a lot of people,
> so I have not really started doing it just yet :)

phylink_create requires a net_device as first argument. what should be
the device for cpu/dsa ports?

Marek