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Date:   Sun, 24 May 2020 16:44:49 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Jeremy Linton <jeremy.linton@arm.com>
Cc:     netdev@vger.kernel.org, davem@davemloft.net, f.fainelli@gmail.com,
        hkallweit1@gmail.com, linux@armlinux.org.uk,
        madalin.bucur@oss.nxp.com, calvin.johnson@oss.nxp.com,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC 08/11] net: phy: Allow mdio buses to auto-probe c45 devices
Message-ID: <20200524144449.GP610998@lunn.ch>
References: <20200522213059.1535892-1-jeremy.linton@arm.com>
 <20200522213059.1535892-9-jeremy.linton@arm.com>
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> +++ b/include/linux/phy.h
> @@ -275,6 +275,11 @@ struct mii_bus {
>  	int reset_delay_us;
>  	/* RESET GPIO descriptor pointer */
>  	struct gpio_desc *reset_gpiod;
> +	/* bus capabilities, used for probing */
> +	enum {
> +		MDIOBUS_C22_ONLY = 0,
> +		MDIOBUS_C45_FIRST,
> +	} probe_capabilities;
>  };


I'm not so keen on _FIRST. It suggest _LAST would also be valid.  But
that then suggests this is not a bus property, but a PHY property, and
some PHYs might need _FIRST and other phys need _LAST, and then you
have a bus which has both sorts of PHY on it, and you have a problem.

So i think it would be better to have

	enum {
		MDIOBUS_UNKNOWN = 0,
		MDIOBUS_C22,
		MDIOBUS_C45,
		MDIOBUS_C45_C22,
	} bus_capabilities;

Describe just what the bus master can support.

	 Andrew