Re: [PATCH net-next v3 3/8] net: qualcomm: ipqess: introduce the Qualcomm IPQESS driver

From: Simon Horman <horms@kernel.org>
To: Romain Gantois <romain.gantois@bootlin.com>
Cc: davem@davemloft.net, Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	devicetree@vger.kernel.org, thomas.petazzoni@bootlin.com,
	Andrew Lunn <andrew@lunn.ch>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Heiner Kallweit <hkallweit1@gmail.com>,
	Russell King <linux@armlinux.org.uk>,
	linux-arm-kernel@lists.infradead.org,
	Vladimir Oltean <vladimir.oltean@nxp.com>,
	Luka Perkov <luka.perkov@sartura.hr>,
	Robert Marko <robert.marko@sartura.hr>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <andersson@kernel.org>,
	Konrad Dybcio <konrad.dybcio@somainline.org>
Subject: Re: [PATCH net-next v3 3/8] net: qualcomm: ipqess: introduce the Qualcomm IPQESS driver
Date: Wed, 15 Nov 2023 18:11:03 +0000	[thread overview]
Message-ID: <20231115181103.GX74656@kernel.org> (raw)
In-Reply-To: <20231114105600.1012056-4-romain.gantois@bootlin.com>

On Tue, Nov 14, 2023 at 11:55:53AM +0100, Romain Gantois wrote:
> The Qualcomm IPQ4019 Ethernet Switch Subsystem for the IPQ4019 chip
> includes an internal Ethernet switch based on the QCA8K IP.
> 
> The CPU-to-switch port data plane depends on the IPQESS EDMA Controller,
> a simple 1G Ethernet controller. It is connected to the switch through an
> internal link, and doesn't expose directly any external interface.
> 
> The EDMA controller has 16 RX and TX queues, with a very basic RSS fanout
> configured at init time.
> 
> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>

Hi Romain,

some minor feedback from my side.

> diff --git a/drivers/net/ethernet/qualcomm/ipqess/ipqess_switch.c b/drivers/net/ethernet/qualcomm/ipqess/ipqess_switch.c

...

> +static int ipqess_switch_probe(struct platform_device *pdev)
> +{

...

> +	for_each_available_child_of_node(ports, port_np) {
> +		ret = ipqess_port_register(sw, port_np);
> +		if (ret) {
> +			pr_err("Failed to register ipqess port! error %d\n", ret);

Coccinelle warns that a call to of_node_put() is needed here.

> +			goto out_ports;
> +		}
> +	}

...

> +static int
> +ipqess_switch_remove(struct platform_device *pdev)
> +{
> +	struct ipqess_switch *sw = platform_get_drvdata(pdev);
> +	struct qca8k_priv *priv = sw->priv;

Here sw is dereferenced...

> +	struct ipqess_port *port = NULL;
> +	int i;
> +
> +	if (!sw)
> +		return 0;

... but here the code guards against sw being NULL.
This seems inconsistent.

As flagged by Smatch.

...

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