From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Akinobu Mita To: linux-iio@vger.kernel.org Cc: Akinobu Mita , Daniel Baluta , Jonathan Cameron Subject: [PATCH v2 10/11] iio: adc: ti-ads1015: use iio_device_claim_direct_mode() Date: Fri, 21 Jul 2017 00:24:26 +0900 Message-Id: <1500564267-8613-11-git-send-email-akinobu.mita@gmail.com> In-Reply-To: <1500564267-8613-1-git-send-email-akinobu.mita@gmail.com> References: <1500564267-8613-1-git-send-email-akinobu.mita@gmail.com> List-ID: 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 Cc: Jonathan Cameron Signed-off-by: Akinobu Mita --- 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 da25780..5568be4 100644 --- a/drivers/iio/adc/ti-ads1015.c +++ b/drivers/iio/adc/ti-ads1015.c @@ -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; } -- 2.7.4