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Subject: Re: [PATCH v2] serial: samsung: Checks the return value of function
To:     Tamseel Shams <m.shams@samsung.com>, gregkh@linuxfoundation.org,
        jirislaby@kernel.org
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-kernel@vger.kernel.org, alim.akhtar@samsung.com
References: <CGME20210630133115epcas5p1706041f122819d47b18b83853b49694e@epcas5p1.samsung.com>
 <20210630133359.59275-1-m.shams@samsung.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Message-ID: <0c608d5e-f59b-3f05-a461-2205cece4b7e@canonical.com>
Date:   Thu, 1 Jul 2021 08:36:21 +0200
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On 30/06/2021 15:33, Tamseel Shams wrote:
> "uart_add_one_port" function call may fail and return
> some error code, so adding a check for return value.
> If it is returning some error code, then displaying the
> result, unregistering the driver and then returning from
> probe function with error code.
> 
> Signed-off-by: Tamseel Shams <m.shams@samsung.com>
> ---
> Changes since v1:
> 1. Added support to unregister driver on failure of "uart_add_onr_port"
> function call.
> 2. Commit message updated.
> 
>  drivers/tty/serial/samsung_tty.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
> index 9fbc61151c2e..188e2d2da201 100644
> --- a/drivers/tty/serial/samsung_tty.c
> +++ b/drivers/tty/serial/samsung_tty.c
> @@ -2253,7 +2253,11 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
>  	}
>  
>  	dev_dbg(&pdev->dev, "%s: adding port\n", __func__);
> -	uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
> +	ret = uart_add_one_port(&s3c24xx_uart_drv, &ourport->port);
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
> +		goto add_port_error;
> +	}
>  	platform_set_drvdata(pdev, &ourport->port);
>  
>  	/*
> @@ -2272,6 +2276,11 @@ static int s3c24xx_serial_probe(struct platform_device *pdev)
>  	probe_index++;
>  
>  	return 0;
> +
> +add_port_error:

You did not unwind fully s3c24xx_serial_init_port() - clocks.

> +	ourport->port.mapbase = 0;
> +	uart_unregister_driver(&s3c24xx_uart_drv);
> +	return ret;
>  }
>  
>  static int s3c24xx_serial_remove(struct platform_device *dev)
> 


Best regards,
Krzysztof