Re: [PATCH 09/10] iio: gyro: adis16136: rework locks using ADIS library's state lock

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 26 Sep 2019 14:18:11 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> This replaces indio_dev's mlock with the state lock/mutex from the ADIS
> library.
> 
> The __adis16136_get_freq() function has been prefixed to mark it as
> unlocked. The adis16136_{set,get}_filter() functions now hold the state
> lock for all the ops that they do.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Applied.

Thanks,

Jonathan

> ---
>  drivers/iio/gyro/adis16136.c | 31 +++++++++++++++++++++----------
>  1 file changed, 21 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iio/gyro/adis16136.c b/drivers/iio/gyro/adis16136.c
> index 5bec7ad53d8b..2d2c48f0b996 100644
> --- a/drivers/iio/gyro/adis16136.c
> +++ b/drivers/iio/gyro/adis16136.c
> @@ -185,12 +185,12 @@ static int adis16136_set_freq(struct adis16136 *adis16136, unsigned int freq)
>  	return adis_write_reg_16(&adis16136->adis, ADIS16136_REG_SMPL_PRD, t);
>  }
>  
> -static int adis16136_get_freq(struct adis16136 *adis16136, unsigned int *freq)
> +static int __adis16136_get_freq(struct adis16136 *adis16136, unsigned int *freq)
>  {
>  	uint16_t t;
>  	int ret;
>  
> -	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_SMPL_PRD, &t);
> +	ret = __adis_read_reg_16(&adis16136->adis, ADIS16136_REG_SMPL_PRD, &t);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -224,10 +224,13 @@ static ssize_t adis16136_read_frequency(struct device *dev,
>  {
>  	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
>  	struct adis16136 *adis16136 = iio_priv(indio_dev);
> +	struct mutex *slock = &adis16136->adis.state_lock;
>  	unsigned int freq;
>  	int ret;
>  
> -	ret = adis16136_get_freq(adis16136, &freq);
> +	mutex_lock(slock);
> +	ret = __adis16136_get_freq(adis16136, &freq);
> +	mutex_unlock(slock);
>  	if (ret < 0)
>  		return ret;
>  
> @@ -252,42 +255,50 @@ static const unsigned adis16136_3db_divisors[] = {
>  static int adis16136_set_filter(struct iio_dev *indio_dev, int val)
>  {
>  	struct adis16136 *adis16136 = iio_priv(indio_dev);
> +	struct mutex *slock = &adis16136->adis.state_lock;
>  	unsigned int freq;
>  	int i, ret;
>  
> -	ret = adis16136_get_freq(adis16136, &freq);
> +	mutex_lock(slock);
> +	ret = __adis16136_get_freq(adis16136, &freq);
>  	if (ret < 0)
> -		return ret;
> +		goto out_unlock;
>  
>  	for (i = ARRAY_SIZE(adis16136_3db_divisors) - 1; i >= 1; i--) {
>  		if (freq / adis16136_3db_divisors[i] >= val)
>  			break;
>  	}
>  
> -	return adis_write_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT, i);
> +	ret = __adis_write_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT, i);
> +out_unlock:
> +	mutex_unlock(slock);
> +
> +	return ret;
>  }
>  
>  static int adis16136_get_filter(struct iio_dev *indio_dev, int *val)
>  {
>  	struct adis16136 *adis16136 = iio_priv(indio_dev);
> +	struct mutex *slock = &adis16136->adis.state_lock;
>  	unsigned int freq;
>  	uint16_t val16;
>  	int ret;
>  
> -	mutex_lock(&indio_dev->mlock);
> +	mutex_lock(slock);
>  
> -	ret = adis_read_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT, &val16);
> +	ret = __adis_read_reg_16(&adis16136->adis, ADIS16136_REG_AVG_CNT,
> +				 &val16);
>  	if (ret < 0)
>  		goto err_unlock;
>  
> -	ret = adis16136_get_freq(adis16136, &freq);
> +	ret = __adis16136_get_freq(adis16136, &freq);
>  	if (ret < 0)
>  		goto err_unlock;
>  
>  	*val = freq / adis16136_3db_divisors[val16 & 0x07];
>  
>  err_unlock:
> -	mutex_unlock(&indio_dev->mlock);
> +	mutex_unlock(slock);
>  
>  	return ret ? ret : IIO_VAL_INT;
>  }