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Date:   Sat, 1 Jul 2023 18:21:14 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Jie Luo <quic_luoj@quicinc.com>
Cc:     hkallweit1@gmail.com, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, linux@armlinux.org.uk,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] net: phy: at803x: add qca8081 fifo reset on the link
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> Hi Andrew,
> it is the PLL related registers, there is no PHY ID existed in MII register
> 2, 3 of this block, so it can't be instantiated as the generic PHY device.

Well, phylib is going to scan those ID registers, and if it finds
something other than 0xffff 0xffff in those two ID registers it is
going to think a PHY is there. And then if there is no driver using
that ID, it will instantiate a generic PHY.

You might be able to see this in /sys/bus/mdio_bus, especially if you
don't have a DT node representing the MDIO bus.

      Andrew