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Commit 47d8cf41 authored by Akinobu Mita's avatar Akinobu Mita Committed by Jonathan Cameron
Browse files

iio: adc: ti-ads1015: use iio_device_claim_direct_mode() 



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@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 4de43d25

drivers/iio/adc/ti-ads1015.c

+7 −8
Original line number Diff line number Diff line
@@ -347,34 +347,34 @@ 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:
@@ -393,7 +393,6 @@ static int ads1015_read_raw(struct iio_dev *indio_dev, 
		break;

	}

	mutex_unlock(&data->lock);

	mutex_unlock(&indio_dev->mlock);



	return ret;

}