[PATCH] iio/light/max44000: Use common error handling code in max44000_probe()

[PATCH] iio/light/max44000: Use common error handling code in max44000_probe()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Thu, 26 Oct 2017 10:30:57 +0200

* Add a jump target so that a specific error message is stored only once
  at the end of this function implementation.

* Replace two calls of the function "dev_err" by goto statements.

* Adjust condition checks.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 drivers/iio/light/max44000.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
index bcdb0eb9e537..8f4bc6a918d5 100644
--- a/drivers/iio/light/max44000.c
+++ b/drivers/iio/light/max44000.c
@@ -569,18 +569,14 @@ static int max44000_probe(struct i2c_client *client,
 	 * Set a middle value so that we get some sort of valid data by default.
 	 */
 	ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed to write init config: %d\n", ret);
-		return ret;
-	}
+	if (ret)
+		goto report_failure;
 
 	/* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
 	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
 	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
-	if (ret < 0) {
-		dev_err(&client->dev, "failed to write init config: %d\n", ret);
-		return ret;
-	}
+	if (ret)
+		goto report_failure;
 
 	/* Read status at least once to clear any stale interrupt bits. */
 	ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
@@ -596,6 +592,10 @@ static int max44000_probe(struct i2c_client *client,
 	}
 
 	return iio_device_register(indio_dev);
+
+report_failure:
+	dev_err(&client->dev, "failed to write init config: %d\n", ret);
+	return ret;
 }
 
 static int max44000_remove(struct i2c_client *client)
-- 
2.14.3

Re: [PATCH] iio/light/max44000: Use common error handling code in max44000_probe()

[Jonathan Cameron]

On Thu, 26 Oct 2017 10:40:12 +0200
SF Markus Elfring <elfring@users.sourceforge.net> wrote:

> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Thu, 26 Oct 2017 10:30:57 +0200
> 
> * Add a jump target so that a specific error message is stored only once
>   at the end of this function implementation.
> 
> * Replace two calls of the function "dev_err" by goto statements.
> 
> * Adjust condition checks.
> 
> This issue was detected by using the Coccinelle software.
> 
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Again, throttle your patch sending please Markus as it will save
everyone time.  I try to give full reasoning in each patch because
others may encounter them without having visibility of similar
patches posted at the same time.  As such I end up writing
the same thing multiple times wasting my time on top of the time
you have already wasted by sending out multiple patches of a type
I am going to reject..

> ---
>  drivers/iio/light/max44000.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/iio/light/max44000.c b/drivers/iio/light/max44000.c
> index bcdb0eb9e537..8f4bc6a918d5 100644
> --- a/drivers/iio/light/max44000.c
> +++ b/drivers/iio/light/max44000.c
> @@ -569,18 +569,14 @@ static int max44000_probe(struct i2c_client *client,
>  	 * Set a middle value so that we get some sort of valid data by default.
>  	 */
>  	ret = max44000_write_led_current_raw(data, MAX44000_LED_CURRENT_DEFAULT);
> -	if (ret < 0) {
> -		dev_err(&client->dev, "failed to write init config: %d\n", ret);
> -		return ret;
> -	}
> +	if (ret)
> +		goto report_failure;
>  
>  	/* Reset CFG bits to ALS_PRX mode which allows easy reading of both values. */
>  	reg = MAX44000_CFG_TRIM | MAX44000_CFG_MODE_ALS_PRX;
>  	ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
> -	if (ret < 0) {
> -		dev_err(&client->dev, "failed to write init config: %d\n", ret);
> -		return ret;
> -	}
> +	if (ret)
> +		goto report_failure;
>  
>  	/* Read status at least once to clear any stale interrupt bits. */
>  	ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
> @@ -596,6 +592,10 @@ static int max44000_probe(struct i2c_client *client,
>  	}
>  
>  	return iio_device_register(indio_dev);
> +
> +report_failure:
> +	dev_err(&client->dev, "failed to write init config: %d\n", ret);
This reduces readability of the code for a very minor gain.  
Printing an error message is not a source of bugs or similar unlike
unwinding some state, so a unified path makes little sense. 


> +	return ret;
>  }
>  
>  static int max44000_remove(struct i2c_client *client)

Re: [PATCH] iio/light/max44000: Use common error handling code in max44000_probe()

[SF Markus Elfring]

>> @@ -596,6 +592,10 @@ static int max44000_probe(struct i2c_client *client,
>>  	}
>>  
>>  	return iio_device_register(indio_dev);
>> +
>> +report_failure:
>> +	dev_err(&client->dev, "failed to write init config: %d\n", ret);
> This reduces readability of the code for a very minor gain.

I got an other software development view on this aspect.


> Printing an error message is not a source of bugs

I find such a general information questionable.

It is also possible to discover various update candidates in this software area.


> or similar unlike unwinding some state, so a unified path makes little sense.

How does such a view fit to the section “7) Centralized exiting of functions”
in the document “coding-style.rst”?

Regards,
Markus

Re: [PATCH] iio/light/max44000: Use common error handling code in max44000_probe()

[Jonathan Cameron]

On Thu, 26 Oct 2017 18:50:14 +0200
SF Markus Elfring <elfring@users.sourceforge.net> wrote:

> >> @@ -596,6 +592,10 @@ static int max44000_probe(struct i2c_client *client,
> >>  	}
> >>  
> >>  	return iio_device_register(indio_dev);
> >> +
> >> +report_failure:
> >> +	dev_err(&client->dev, "failed to write init config: %d\n", ret);  
> > This reduces readability of the code for a very minor gain.  
> 
> I got an other software development view on this aspect.
> 

Sadly I am going to put my foot down here before more time
is wasted. I am not going to discuss it further after this email.
(for others please see the amount of time already wasted on
what are mostly poor code changes from Markus).

> 
> > Printing an error message is not a source of bugs  
> 
> I find such a general information questionable.
> 
> It is also possible to discover various update candidates in this software area.
Judge each one carefully.  You need to be convincingly improving the code
not just obeying rules blindly.

> 
> 
> > or similar unlike unwinding some state, so a unified path makes little sense.  
> 
> How does such a view fit to the section “7) Centralized exiting of functions”
> in the document “coding-style.rst”?
All rules in there need to be applied with care. If they make the code
worse do not blindly apply them.

> 
> Regards,
> Markus
> --
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