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Date: Sat, 13 Sep 2025 14:01:37 +0100
From: Simon Horman <horms@kernel.org>
To: Christian Marangi <ansuelsmth@gmail.com>
Cc: Lee Jones <lee@kernel.org>, Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	"Chester A. Unal" <chester.a.unal@arinc9.com>,
	Daniel Golle <daniel@makrotopia.org>,
	DENG Qingfang <dqfext@gmail.com>,
	Sean Wang <sean.wang@mediatek.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, netdev@vger.kernel.org,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [net-next PATCH v17 6/8] mfd: an8855: Add support for Airoha
 AN8855 Switch MFD
Message-ID: <20250913130137.GL224143@horms.kernel.org>
References: <20250911133929.30874-1-ansuelsmth@gmail.com>
 <20250911133929.30874-7-ansuelsmth@gmail.com>
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In-Reply-To: <20250911133929.30874-7-ansuelsmth@gmail.com>

On Thu, Sep 11, 2025 at 03:39:21PM +0200, Christian Marangi wrote:
> Add support for Airoha AN8855 Switch MFD that provide support for a DSA
> switch and a NVMEM provider.
> 
> Also make use of the mdio-regmap driver and register a regmap for each
> internal PHY of the switch.
> This is needed to handle the double usage of the PHYs as both PHY and
> Switch accessor.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

...

> diff --git a/drivers/mfd/airoha-an8855.c b/drivers/mfd/airoha-an8855.c

...

> +static int an855_mdio_register(struct device *dev, struct an8855_core_priv *priv)
> +{
> +	struct device_node *mdio_np;
> +	int ret;
> +
> +	mdio_np = of_get_child_by_name(dev->of_node, "mdio");
> +	if (!mdio_np)
> +		return -ENODEV;
> +
> +	for_each_available_child_of_node_scoped(mdio_np, phy_np) {
> +		ret = an8855_phy_register(dev, priv, phy_np);
> +		if (ret)
> +			break;
> +	}

Hi Christian,

Maybe it cannot happen, but if the loop above iterates zero times,
then ret will be used uninitialised below.

Flagged by Smatch.

> +
> +	of_node_put(mdio_np);
> +	return ret;
> +}

...