Re: [RFC PATCH v2 2/2] staging: iio: ad7192: use iio_device_{claim|release}_direct_mode()

[Jonathan Cameron <jic23@kernel.org>]

On 09/03/16 19:30, Alison Schofield wrote:
> Replace the code that guarantees the device stays in direct mode with
> iio_device_{claim|release}_direct_mode() which does same.
> 
> Signed-off-by: Alison Schofield <amsfield22@gmail.com>
A small improvement inline - don't eat the errors within the
driver. 

Jonathan
> ---
>  drivers/staging/iio/adc/ad7192.c | 24 +++++++++---------------
>  1 file changed, 9 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
> index f843f19..94a2e06 100644
> --- a/drivers/staging/iio/adc/ad7192.c
> +++ b/drivers/staging/iio/adc/ad7192.c
> @@ -349,11 +349,9 @@ static ssize_t ad7192_write_frequency(struct device *dev,
>  	if (lval == 0)
>  		return -EINVAL;
>  
> -	mutex_lock(&indio_dev->mlock);
> -	if (iio_buffer_enabled(indio_dev)) {
> -		mutex_unlock(&indio_dev->mlock);
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
>  		return -EBUSY;
return ret;  In theory we might be returning some other
error code so best not to 'eat' the result.
> -	}
>  
>  	div = st->mclk / (lval * st->f_order * 1024);
>  	if (div < 1 || div > 1023) {
> @@ -366,7 +364,7 @@ static ssize_t ad7192_write_frequency(struct device *dev,
>  	ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
>  
>  out:
> -	mutex_unlock(&indio_dev->mlock);
> +	iio_device_release_direct_mode(indio_dev);
>  
>  	return ret ? ret : len;
>  }
> @@ -434,11 +432,9 @@ static ssize_t ad7192_set(struct device *dev,
>  	if (ret < 0)
>  		return ret;
>  
> -	mutex_lock(&indio_dev->mlock);
> -	if (iio_buffer_enabled(indio_dev)) {
> -		mutex_unlock(&indio_dev->mlock);
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
>  		return -EBUSY;
Same here.
> -	}
>  
>  	switch ((u32)this_attr->address) {
>  	case AD7192_REG_GPOCON:
> @@ -461,7 +457,7 @@ static ssize_t ad7192_set(struct device *dev,
>  		ret = -EINVAL;
>  	}
>  
> -	mutex_unlock(&indio_dev->mlock);
> +	iio_device_release_direct_mode(indio_dev);
>  
>  	return ret ? ret : len;
>  }
> @@ -555,11 +551,9 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
>  	int ret, i;
>  	unsigned int tmp;
>  
> -	mutex_lock(&indio_dev->mlock);
> -	if (iio_buffer_enabled(indio_dev)) {
> -		mutex_unlock(&indio_dev->mlock);
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
>  		return -EBUSY;
And here.
> -	}
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SCALE:
> @@ -582,7 +576,7 @@ static int ad7192_write_raw(struct iio_dev *indio_dev,
>  		ret = -EINVAL;
>  	}
>  
> -	mutex_unlock(&indio_dev->mlock);
> +	iio_device_release_direct_mode(indio_dev);
>  
>  	return ret;
>  }
>