Re: [PATCH v2 09/27] iio: adc: ad4000: Stop using iio_device_claim_direct_scoped()

[Nuno Sá <noname.nuno@xxxxxxxxx>]

On Sun, 2025-02-09 at 18:06 +0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> 
> This complex cleanup.h use case of conditional guards has proved
> to be more trouble that it is worth in terms of false positive compiler
> warnings and hard to read code.
> 
> Move directly to the new claim/release_direct() that allow sparse
> to check for unbalanced context.
> 
> Reviewed-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx>
> Tested-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx>
> Reviewed-by: David Lechner <dlechner@xxxxxxxxxxxx>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---

Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx>

>  drivers/iio/adc/ad4000.c | 60 +++++++++++++++++++++++++---------------
>  1 file changed, 37 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/iio/adc/ad4000.c b/drivers/iio/adc/ad4000.c
> index 1d556a842a68..4fe8dee48da9 100644
> --- a/drivers/iio/adc/ad4000.c
> +++ b/drivers/iio/adc/ad4000.c
> @@ -535,12 +535,16 @@ static int ad4000_read_raw(struct iio_dev *indio_dev,
>  			   int *val2, long info)
>  {
>  	struct ad4000_state *st = iio_priv(indio_dev);
> +	int ret;
>  
>  	switch (info) {
>  	case IIO_CHAN_INFO_RAW:
> -		iio_device_claim_direct_scoped(return -EBUSY, indio_dev)
> -			return ad4000_single_conversion(indio_dev, chan,
> val);
> -		unreachable();
> +		if (!iio_device_claim_direct(indio_dev))
> +			return -EBUSY;
> +
> +		ret = ad4000_single_conversion(indio_dev, chan, val);
> +		iio_device_release_direct(indio_dev);
> +		return ret;
>  	case IIO_CHAN_INFO_SCALE:
>  		*val = st->scale_tbl[st->span_comp][0];
>  		*val2 = st->scale_tbl[st->span_comp][1];
> @@ -585,36 +589,46 @@ static int ad4000_write_raw_get_fmt(struct iio_dev
> *indio_dev,
>  	}
>  }
>  
> -static int ad4000_write_raw(struct iio_dev *indio_dev,
> -			    struct iio_chan_spec const *chan, int val, int
> val2,
> -			    long mask)
> +static int __ad4000_write_raw(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int val2)
>  {
>  	struct ad4000_state *st = iio_priv(indio_dev);
>  	unsigned int reg_val;
>  	bool span_comp_en;
>  	int ret;
>  
> -	switch (mask) {
> -	case IIO_CHAN_INFO_SCALE:
> -		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
> -			guard(mutex)(&st->lock);
> +	guard(mutex)(&st->lock);
> +
> +	ret = ad4000_read_reg(st, &reg_val);
> +	if (ret < 0)
> +		return ret;
> +
> +	span_comp_en = val2 == st->scale_tbl[1][1];
> +	reg_val &= ~AD4000_CFG_SPAN_COMP;
> +	reg_val |= FIELD_PREP(AD4000_CFG_SPAN_COMP, span_comp_en);
>  
> -			ret = ad4000_read_reg(st, &reg_val);
> -			if (ret < 0)
> -				return ret;
> +	ret = ad4000_write_reg(st, reg_val);
> +	if (ret < 0)
> +		return ret;
>  
> -			span_comp_en = val2 == st->scale_tbl[1][1];
> -			reg_val &= ~AD4000_CFG_SPAN_COMP;
> -			reg_val |= FIELD_PREP(AD4000_CFG_SPAN_COMP,
> span_comp_en);
> +	st->span_comp = span_comp_en;
> +	return 0;
> +}
>  
> -			ret = ad4000_write_reg(st, reg_val);
> -			if (ret < 0)
> -				return ret;
> +static int ad4000_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val, int val2, long mask)
> +{
> +	int ret;
>  
> -			st->span_comp = span_comp_en;
> -			return 0;
> -		}
> -		unreachable();
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		if (!iio_device_claim_direct(indio_dev))
> +			return -EBUSY;
> +		ret = __ad4000_write_raw(indio_dev, chan, val2);
> +		iio_device_release_direct(indio_dev);
> +		return ret;
>  	default:
>  		return -EINVAL;
>  	}