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Date:   Thu, 19 Oct 2023 20:13:08 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Andrew Lunn <andrew@lunn.ch>,
        Eric Dumazet <edumazet@google.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Woojung Huh <woojung.huh@microchip.com>,
        Arun Ramadoss <arun.ramadoss@microchip.com>,
        Conor Dooley <conor+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Florian Fainelli <florian.fainelli@broadcom.com>,
        kernel@pengutronix.de, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, UNGLinuxDriver@microchip.com,
        "Russell King (Oracle)" <linux@armlinux.org.uk>,
        devicetree@vger.kernel.org
Subject: Re: [PATCH net-next v6 7/9] net: dsa: microchip: Add error handling
 for ksz_switch_macaddr_get()
Message-ID: <20231019171308.tpjdevvnrqhly6cu@skbuf>
References: <20231019122850.1199821-1-o.rempel@pengutronix.de>
 <20231019122850.1199821-8-o.rempel@pengutronix.de>
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In-Reply-To: <20231019122850.1199821-8-o.rempel@pengutronix.de>
Precedence: bulk

On Thu, Oct 19, 2023 at 02:28:48PM +0200, Oleksij Rempel wrote:
> Enhance the ksz_switch_macaddr_get() function to handle errors that may
> occur during the call to ksz_write8(). Specifically, this update checks
> the return value of ksz_write8(), which may fail if regmap ranges
> validation is not passed and returns the error code.
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---
>  drivers/net/dsa/microchip/ksz_common.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index 7b05de6fe987..79052a54880c 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -3612,7 +3612,7 @@ int ksz_switch_macaddr_get(struct dsa_switch *ds, int port,
>  	struct ksz_switch_macaddr *switch_macaddr;
>  	struct ksz_device *dev = ds->priv;
>  	const u16 *regs = dev->info->regs;
> -	int i;
> +	int i, ret;
>  
>  	/* Make sure concurrent MAC address changes are blocked */
>  	ASSERT_RTNL();
> @@ -3639,8 +3639,11 @@ int ksz_switch_macaddr_get(struct dsa_switch *ds, int port,
>  	dev->switch_macaddr = switch_macaddr;
>  
>  	/* Program the switch MAC address to hardware */
> -	for (i = 0; i < ETH_ALEN; i++)
> -		ksz_write8(dev, regs[REG_SW_MAC_ADDR] + i, addr[i]);
> +	for (i = 0; i < ETH_ALEN; i++) {
> +		ret = ksz_write8(dev, regs[REG_SW_MAC_ADDR] + i, addr[i]);
> +		if (ret)
> +			return ret;
> +	}

I understand that you intend the error to be fatal, but this leaks memory and a refcount.