Re: [PATCH] iio: adc: exynos5_adc: fix compilation warnings

[Lars-Peter Clausen <lars@metafoo.de>]

On 03/06/2013 05:11 AM, Naveen Krishna Chatradhi wrote:
> From: Naveen Krishna Ch <ch.naveen@samsung.com>
> 
> Fixes the compilation warnings and potential NULL pointer
> dereferencing pointed out by "Dan Carpenter".
> 

I'd say that's a rather un-potential NULL pointer dereferencing, but if it
makes the static checkers happy, why not. Since the same match table is used to
match the device, probe won't be called unless there is a match, so
of_match_node() will never return NULL in this case.

> Signed-off-by: Naveen Krishna Ch <ch.naveen@samsung.com>
> ---
>  drivers/iio/adc/exynos_adc.c |   24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/iio/adc/exynos_adc.c b/drivers/iio/adc/exynos_adc.c
> index ed6fdd7..67d07aa 100644
> --- a/drivers/iio/adc/exynos_adc.c
> +++ b/drivers/iio/adc/exynos_adc.c
> @@ -92,7 +92,7 @@ struct exynos_adc {
>  	struct completion	completion;
>  
>  	u32			value;
> -	unsigned int            version;
> +	unsigned int		version;
>  };
>  
>  static const struct of_device_id exynos_adc_match[] = {
> @@ -102,12 +102,15 @@ static const struct of_device_id exynos_adc_match[] = {
>  };
>  MODULE_DEVICE_TABLE(of, exynos_adc_match);
>  
> -static inline unsigned int exynos_adc_get_version(struct platform_device *pdev)
> +static inline int exynos_adc_get_version(struct platform_device *pdev)
>  {
>  	const struct of_device_id *match;
>  
>  	match = of_match_node(exynos_adc_match, pdev->dev.of_node);
> -	return (unsigned int)match->data;
> +	if (!match)
> +		return -ENODEV;
> +
> +	return (int)match->data;
>  }
>  
>  static int exynos_read_raw(struct iio_dev *indio_dev,
> @@ -117,7 +120,7 @@ static int exynos_read_raw(struct iio_dev *indio_dev,
>  				long mask)
>  {
>  	struct exynos_adc *info = iio_priv(indio_dev);
> -	unsigned long timeout;
> +	int timeout;
>  	u32 con1, con2;
>  
>  	if (mask != IIO_CHAN_INFO_RAW)
> @@ -255,7 +258,7 @@ static int exynos_adc_probe(struct platform_device *pdev)
>  	struct iio_dev *indio_dev = NULL;
>  	struct resource	*mem;
>  	int ret = -ENODEV;
> -	int irq;
> +	int irq, version;
>  
>  	if (!np)
>  		return ret;
> @@ -268,6 +271,15 @@ static int exynos_adc_probe(struct platform_device *pdev)
>  
>  	info = iio_priv(indio_dev);
>  
> +	version = exynos_adc_get_version(pdev);
> +	if (version < 0) {
> +		dev_err(&pdev->dev, "no matching of_node, err = %d\n", version);
> +		ret = version;
> +		goto err_iio;
> +	}
> +
> +	info->version = version;
> +
>  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  
>  	info->regs = devm_request_and_ioremap(&pdev->dev, mem);
> @@ -311,8 +323,6 @@ static int exynos_adc_probe(struct platform_device *pdev)
>  		goto err_irq;
>  	}
>  
> -	info->version = exynos_adc_get_version(pdev);
> -
>  	platform_set_drvdata(pdev, indio_dev);
>  
>  	indio_dev->name = dev_name(&pdev->dev);