Re: [PATCH v2 3/9] iio: inkern: Check error explicitly in iio_channel_read_max()

[Jonathan Cameron]

On Tue, 23 May 2023 17:12:17 +0200
Herve Codina <herve.codina@xxxxxxxxxxx> wrote:

> The current implementation returns the error code as part of the
> default switch case.
> This can lead to returning an incorrect positive value in case of
> iio_avail_type enum entries evolution.
> 
> In order to avoid this case, be more strict in error checking.
> 
> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
It's an odd code construct, so in the interests of robustness this
looks like a good improvement to me.

Given the later patch you need for this series will see some fuzz
I think if I pick this up separately I'll currently assume this whole
series will go together.

Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

> ---
>  drivers/iio/inkern.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
> index 872fd5c24147..f738db9a0c04 100644
> --- a/drivers/iio/inkern.c
> +++ b/drivers/iio/inkern.c
> @@ -858,6 +858,9 @@ static int iio_channel_read_max(struct iio_channel *chan,
>  		val2 = &unused;
>  
>  	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
> +	if (ret < 0)
> +		return ret;
> +
>  	switch (ret) {
>  	case IIO_AVAIL_RANGE:
>  		switch (*type) {
> @@ -888,7 +891,7 @@ static int iio_channel_read_max(struct iio_channel *chan,
>  		return 0;
>  
>  	default:
> -		return ret;
> +		return -EINVAL;
>  	}
>  }
>