Re: [PATCH v2] lan743x: add virtual PHY for PHY-less devices

From: Sergej Bauer
Date: Tue Jan 26 2021 - 14:46:28 EST


On Saturday, January 23, 2021 2:23:25 AM MSK Andrew Lunn wrote:
> > > > @@ -1000,8 +1005,10 @@ static void lan743x_phy_close(struct
> > > > lan743x_adapter *adapter)>
> > > >
> > > > struct net_device *netdev = adapter->netdev;
> > > >
> > > > phy_stop(netdev->phydev);
> > > >
> > > > - phy_disconnect(netdev->phydev);
> > > > - netdev->phydev = NULL;
> > > > + if (phy_is_pseudo_fixed_link(netdev->phydev))
> > > > + lan743x_virtual_phy_disconnect(netdev->phydev);
> > > > + else
> > > > + phy_disconnect(netdev->phydev);
> > >
> > > phy_disconnect() should work. You might want to call
>
> There are drivers which call phy_disconnect() on a fixed_link. e.g.
>
> https://elixir.bootlin.com/linux/v5.11-rc4/source/drivers/net/usb/lan78xx.c#
> L3555.
>
> It could be your missing call to fixed_phy_unregister() is leaving
> behind bad state.
>
fixed_phy_unregister() were inside of lan743x_virtual_phy_disconnect()

> > It was to make ethtool show full set of supported speeds and MII only in
> > supported ports (without TP and the no any ports in the bare card).
>
> But fixed link does not support the full set of speed. It is fixed. It
> supports only one speed it is configured with. And by setting it
> wrongly, you are going to allow the user to do odd things, like use
> ethtool force the link speed to a speed which is not actually
> supported.
when writing virtual phy i have used "Microchip AN2948 Configuration Registers
of LAN743x" document and the lan743x is designed only for LAN7430 either
LAN7431 as it pointed in the document and in lan743x_pcidev_tbl. which both
support speeds 10/100/1000 Mbps.


--
Regards,
Sergej.