On Thu, 13 Jul 2017 01:32:03 +0900
Akinobu Mita <akinobu.mita@xxxxxxxxx> wrote:
> While the iio buffer for the ti-ads1015 driver is enabled, reading the
> raw ADC channel data is restricted. We usually use the
> iio_device_claim_direct_mode()/iio_device_release_direct_mode() pair for
> that.
>
> This change consequently reverses the locking order for the driver's
> private lock and indio_dev->mlock which acquired by
> iio_device_claim_direct_mode() internally. But it's safe because there is
> no other dependency between these locks.
>
> Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Sensible cleanup. Will pick up when rest are sorted.
Jonathan
> ---
> drivers/iio/adc/ti-ads1015.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
> index 821e649..dfeb3af 100644
> --- a/drivers/iio/adc/ti-ads1015.c
> +++ b/drivers/iio/adc/ti-ads1015.c
> @@ -340,34 +340,34 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
> int ret, idx;
> struct ads1015_data *data = iio_priv(indio_dev);
>
> - mutex_lock(&indio_dev->mlock);
> mutex_lock(&data->lock);
> switch (mask) {
> case IIO_CHAN_INFO_RAW: {
> int shift = chan->scan_type.shift;
>
> - if (iio_buffer_enabled(indio_dev)) {
> - ret = -EBUSY;
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> break;
> - }
>
> ret = ads1015_set_power_state(data, true);
> if (ret < 0)
> - break;
> + goto release_direct;
>
> ret = ads1015_get_adc_result(data, chan->address, val);
> if (ret < 0) {
> ads1015_set_power_state(data, false);
> - break;
> + goto release_direct;
> }
>
> *val = sign_extend32(*val >> shift, 15 - shift);
>
> ret = ads1015_set_power_state(data, false);
> if (ret < 0)
> - break;
> + goto release_direct;
>
> ret = IIO_VAL_INT;
> +release_direct:
> + iio_device_release_direct_mode(indio_dev);
> break;
> }
> case IIO_CHAN_INFO_SCALE:
> @@ -386,7 +386,6 @@ static int ads1015_read_raw(struct iio_dev *indio_dev,
> break;
> }
> mutex_unlock(&data->lock);
> - mutex_unlock(&indio_dev->mlock);
>
> return ret;
> }
--
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