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Date:   Tue, 25 May 2021 15:34:34 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Wong Vee Khee <vee.khee.wong@linux.intel.com>
Cc:     Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC net-next 0/2] Introduce MDIO probe order C45 over C22
Message-ID: <YKz86iMwoP3VT4uh@lunn.ch>
References: <20210525055803.22116-1-vee.khee.wong@linux.intel.com>
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On Tue, May 25, 2021 at 01:58:03PM +0800, Wong Vee Khee wrote:
> Synopsys MAC controller is capable of pairing with external PHY devices
> that accessible via Clause-22 and Clause-45.
> 
> There is a problem when it is paired with Marvell 88E2110 which returns
> PHY ID of 0 using get_phy_c22_id(). We can add this check in that
> function, but this will break swphy, as swphy_reg_reg() return 0. [1]

Is it possible to identify it is a Marvell PHY? Do any of the other
C22 registers return anything unique? I'm wondering if adding
.match_phy_device to genphy would work to identify it is a Marvell PHY
and not bind to it. Or we can turn it around, make the
.match_phy_device specifically look for the fixed-link device by
putting a magic number in one of the vendor registers.

    Andrew