Re: [PATCH] iio: adc: max9611: explicitly cast gain_selectors

From: Jonathan Cameron
Date: Sun Aug 19 2018 - 12:50:03 EST


On Sat, 11 Aug 2018 11:12:19 +0200
Stefan Agner <stefan@xxxxxxxx> wrote:

> After finding a reasonable gain, the function converts the configured
> gain to a gain configuration option selector enum max9611_csa_gain.
> Make the conversion clearly visible by using an explicit cast. This
> also avoids a warning seen with clang:
> drivers/iio/adc/max9611.c:292:16: warning: implicit conversion from
> enumeration type 'enum max9611_conf_ids' to different enumeration
> type 'enum max9611_csa_gain' [-Wenum-conversion]
> *csa_gain = gain_selectors[i];
> ~ ^~~~~~~~~~~~~~~~~
>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
Hmm. This is a somewhat odd code construct, but it kind of makes sense
as it enforces that we are using a subset of one enum for the other.

Not terribly pretty but not awful I guess.

This patch is fine given that.

Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
> drivers/iio/adc/max9611.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
> index 0538ff8c4ac1..643a4e66eb80 100644
> --- a/drivers/iio/adc/max9611.c
> +++ b/drivers/iio/adc/max9611.c
> @@ -289,7 +289,7 @@ static int max9611_read_csa_voltage(struct max9611_dev *max9611,
> return ret;
>
> if (*adc_raw > 0) {
> - *csa_gain = gain_selectors[i];
> + *csa_gain = (enum max9611_csa_gain)gain_selectors[i];
> return 0;
> }
> }