Date: Wed, 27 Sep 2017 16:12:13 +0200
From: Andrew Lunn <andrew@lunn.ch>
To: Corentin Labbe <clabbe.montjoie@gmail.com>
Cc: robh+dt@kernel.org, mark.rutland@arm.com,
        maxime.ripard@free-electrons.com, wens@csie.org, linux@armlinux.org.uk,
        catalin.marinas@arm.com, will.deacon@arm.com, peppe.cavallaro@st.com,
        alexandre.torgue@st.com, f.fainelli@gmail.com, frowand.list@gmail.com,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-sunxi@googlegroups.com
Subject: Re: [PATCH v6 11/11] of: mdio: Prevent of_mdiobus_register from
 scanning mdio-mux nodes
Message-ID: <20170927141213.GF13516@lunn.ch>
References: <20170927073414.17361-1-clabbe.montjoie@gmail.com>
 <20170927073414.17361-12-clabbe.montjoie@gmail.com>
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On Wed, Sep 27, 2017 at 09:34:14AM +0200, Corentin Labbe wrote:
> Each child node of an MDIO node is scanned as a PHY when calling
> of_mdiobus_register() givint the following result:
> [   18.175379] mdio_bus stmmac-0: /soc/ethernet@1c30000/mdio/mdio-mux has invalid PHY address
> [   18.175408] mdio_bus stmmac-0: scan phy mdio-mux at address 0
> [   18.175450] mdio_bus stmmac-0: scan phy mdio-mux at address 1
> [...]
> [   18.176420] mdio_bus stmmac-0: scan phy mdio-mux at address 30
> [   18.176452] mdio_bus stmmac-0: scan phy mdio-mux at address 31
> 
> Since mdio-mux nodes are not PHY, this patch a way to to not scan
> them.

Hi Corentin

I still don't like this, but ...

> 
> Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
> ---
>  drivers/of/of_mdio.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
> index d94dd8b77abd..d90ddb0d90f2 100644
> --- a/drivers/of/of_mdio.c
> +++ b/drivers/of/of_mdio.c
> @@ -190,6 +190,10 @@ int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
>  	struct device_node *child;
>  	bool scanphys = false;
>  	int addr, rc;
> +	static const struct of_device_id do_not_scan[] = {
> +		{ .compatible = "mdio-mux" },
> +		{}
> +	};

Please rename this to some less generic. What i don't want is other
compatible strings added here. We want to make the exception for
muxes, but nothing else. So something like compatible_muxes?

       Andrew