[PATCH v2] serial: samsung: Checks the return value of function

[PATCH v2] serial: samsung: Checks the return value of function

[Tamseel Shams]

"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:
+	ourport->port.mapbase = 0;
+	uart_unregister_driver(&s3c24xx_uart_drv);
+	return ret;
 }
 
 static int s3c24xx_serial_remove(struct platform_device *dev)
-- 
2.17.1


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Re: [PATCH v2] serial: samsung: Checks the return value of function

[Krzysztof Kozlowski]

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

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RE: [PATCH v2] serial: samsung: Checks the return value of function

[M Tamseel Shams]

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
> Sent: Thursday, July 1, 2021 12:06 PM
> 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
> Subject: Re: [PATCH v2] serial: samsung: Checks the return value of function
> 
> 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.
> 
Hi Krzysztof,

Yeah, missed the unwinding of clocks.
Will fix this in next version.

Thanks & Regards,
Tamseel Shams


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