Re: [PATCH] iio/adc/palmas: Use common error handling code in palmas_gpadc_calibrate()

Jonathan Cameron
2017-10-26T16:33:14Z

On Thu, 26 Oct 2017 08:08:49 +0200
SF Markus Elfring <elfring@users.sourceforge.net> wrote:

> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Thu, 26 Oct 2017 07:58:03 +0200
>
> * Add a jump target so that a specific error message is stored only once
> at the end of this function implementation.
>
> * Adjust condition checks.
>
> This issue was detected by using the Coccinelle software.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>

Markus,

You need to a apply a check in these cases. If the code is harder
to read afterwards and hence more prone to bugs being introduced
now or in future, it is not a good change.

As such I won't be taking this sort of change.

Jonathan
> ---
> drivers/iio/adc/palmas_gpadc.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
> index 69b9affeef1e..5e6566692d46 100644
> --- a/drivers/iio/adc/palmas_gpadc.c
> +++ b/drivers/iio/adc/palmas_gpadc.c
> @@ -304,17 +304,13 @@ static int palmas_gpadc_calibrate(struct palmas_gpadc *adc, int adc_chan)
>
> ret = palmas_read(adc->palmas, PALMAS_TRIM_GPADC_BASE,
> adc->adc_info[adc_chan].trim1_reg, &d1);
> - if (ret < 0) {
> - dev_err(adc->dev, "TRIM read failed: %d\n", ret);
> - goto scrub;
> - }
> + if (ret)
> + goto report_failure;
>
> ret = palmas_read(adc->palmas, PALMAS_TRIM_GPADC_BASE,
> adc->adc_info[adc_chan].trim2_reg, &d2);
> - if (ret < 0) {
> - dev_err(adc->dev, "TRIM read failed: %d\n", ret);
> - goto scrub;
> - }
> + if (ret)
> + goto report_failure;
>
> /* gain error calculation */
> k = (1000 + (1000 * (d2 - d1)) / (x2 - x1));
> @@ -329,6 +325,10 @@ static int palmas_gpadc_calibrate(struct palmas_gpadc *adc, int adc_chan)
>
> scrub:
> return ret;
> +
> +report_failure:

This makes for complex code flow where it is not needed. As such I am
not going to even think about taking this sort of patch.

> + dev_err(adc->dev, "TRIM read failed: %d\n", ret);
> + goto scrub;
> }
>
> static int palmas_gpadc_start_conversion(struct palmas_gpadc *adc, int adc_chan)