[patch v3] iio: tsl4531: fix error handling in tsl4531_check_id()

[patch v3] iio: tsl4531: fix error handling in tsl4531_check_id()

[Dan Carpenter]

The tsl4531_check_id() function returned 1 on "found" and 0 on "not
found" and negative error codes on failure.  This was non-standard and
bug prone.  The caller treated all non-zero values including error codes
as "found".

This patch fixes it by changing the tsl4531_check_id() to return zero on
success or a negative error code, and updates the caller.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v3: slightly different fix again
v2: different fix

diff --git a/drivers/iio/light/tsl4531.c b/drivers/iio/light/tsl4531.c
index 2697918..cf94ec7 100644
--- a/drivers/iio/light/tsl4531.c
+++ b/drivers/iio/light/tsl4531.c
@@ -158,9 +158,9 @@ static int tsl4531_check_id(struct i2c_client *client)
 	case TSL45313_ID:
 	case TSL45315_ID:
 	case TSL45317_ID:
-		return 1;
-	default:
 		return 0;
+	default:
+		return -ENODEV;
 	}
 }
 
@@ -180,9 +180,10 @@ static int tsl4531_probe(struct i2c_client *client,
 	data->client = client;
 	mutex_init(&data->lock);
 
-	if (!tsl4531_check_id(client)) {
+	ret = tsl4531_check_id(client);
+	if (ret) {
 		dev_err(&client->dev, "no TSL4531 sensor\n");
-		return -ENODEV;
+		return ret;
 	}
 
 	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONTROL,

Re: [patch v3] iio: tsl4531: fix error handling in tsl4531_check_id()

[Jonathan Cameron]

On 18/08/15 10:16, Dan Carpenter wrote:
> The tsl4531_check_id() function returned 1 on "found" and 0 on "not
> found" and negative error codes on failure.  This was non-standard and
> bug prone.  The caller treated all non-zero values including error codes
> as "found".
> 
> This patch fixes it by changing the tsl4531_check_id() to return zero on
> success or a negative error code, and updates the caller.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Applied to the fixes-togreg branch of iio.git.

Given it's just a slightly different approach to the v2 that
Peter acked, I pulled that ack in here as well.

Thanks,

Jonathan
> ---
> v3: slightly different fix again
> v2: different fix
> 
> diff --git a/drivers/iio/light/tsl4531.c b/drivers/iio/light/tsl4531.c
> index 2697918..cf94ec7 100644
> --- a/drivers/iio/light/tsl4531.c
> +++ b/drivers/iio/light/tsl4531.c
> @@ -158,9 +158,9 @@ static int tsl4531_check_id(struct i2c_client *client)
>  	case TSL45313_ID:
>  	case TSL45315_ID:
>  	case TSL45317_ID:
> -		return 1;
> -	default:
>  		return 0;
> +	default:
> +		return -ENODEV;
>  	}
>  }
>  
> @@ -180,9 +180,10 @@ static int tsl4531_probe(struct i2c_client *client,
>  	data->client = client;
>  	mutex_init(&data->lock);
>  
> -	if (!tsl4531_check_id(client)) {
> +	ret = tsl4531_check_id(client);
> +	if (ret) {
>  		dev_err(&client->dev, "no TSL4531 sensor\n");
> -		return -ENODEV;
> +		return ret;
>  	}
>  
>  	ret = i2c_smbus_write_byte_data(data->client, TSL4531_CONTROL,
>