When reading the fault attribute, an empty string was printed if the
fault register value was non-zero.

This is fixed by checking that the return value is less than zero
instead of not zero.

Also always print two hex digits while we are touching this line.

Signed-off-by: David Lechner <dlechner@baylibre.com>
---
 drivers/staging/iio/resolver/ad2s1210.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
index 06de5823eb8e..84743e31261a 100644
--- a/drivers/staging/iio/resolver/ad2s1210.c
+++ b/drivers/staging/iio/resolver/ad2s1210.c
@@ -393,7 +393,7 @@ static ssize_t ad2s1210_show_fault(struct device *dev,
 	ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
 	mutex_unlock(&st->lock);
 
-	return ret ? ret : sprintf(buf, "0x%x\n", ret);
+	return (ret < 0) ? ret : sprintf(buf, "0x%02x\n", ret);
 }
 
 static ssize_t ad2s1210_clear_fault(struct device *dev,
-- 
2.34.1

On Thu, 21 Sep 2023 09:43:44 -0500
David Lechner <dlechner@baylibre.com> wrote:

> When reading the fault attribute, an empty string was printed if the
> fault register value was non-zero.
> 
> This is fixed by checking that the return value is less than zero
> instead of not zero.
> 
> Also always print two hex digits while we are touching this line.
> 
> Signed-off-by: David Lechner <dlechner@baylibre.com>
To trim this set down as quickly as possible I'll pick up anything
I can as I read through them.

Applied this one to the togreg branch of iio.git and pushed out as
testing for 0-day etc to poke it.

I doubt it's worth backporting but I don't think we mind if the bots
find it and people want to carry it in stable.

Thanks,

Jonathan

> ---
>  drivers/staging/iio/resolver/ad2s1210.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index 06de5823eb8e..84743e31261a 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -393,7 +393,7 @@ static ssize_t ad2s1210_show_fault(struct device *dev,
>  	ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
>  	mutex_unlock(&st->lock);
>  
> -	return ret ? ret : sprintf(buf, "0x%x\n", ret);
> +	return (ret < 0) ? ret : sprintf(buf, "0x%02x\n", ret);
>  }
>  
>  static ssize_t ad2s1210_clear_fault(struct device *dev,