From: Nuno Sá nuno.sa@analog.com
commit 20228a1d5a55e7db0c6720840f2c7d2b48c55f69 upstream.
Drop 'mlock' usage by making use of iio_device_claim_direct_mode(). This change actually makes sure we cannot do a single conversion while buffering is enable. Note there was a potential race in the previous code since we were only acquiring the lock after checking if the bus is enabled.
Fixes: af3008485ea0 ("iio:adc: Add common code for ADI Sigma Delta devices") Signed-off-by: Nuno Sá nuno.sa@analog.com Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com Cc: Stable@vger.kernel.org #No rush as race is very old. Link: https://lore.kernel.org/r/20220920112821.975359-2-nuno.sa@analog.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/ad_sigma_delta.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -280,10 +280,10 @@ int ad_sigma_delta_single_conversion(str unsigned int data_reg; int ret = 0;
- if (iio_buffer_enabled(indio_dev)) - return -EBUSY; + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret;
- mutex_lock(&indio_dev->mlock); ad_sigma_delta_set_channel(sigma_delta, chan->address);
spi_bus_lock(sigma_delta->spi->master); @@ -322,7 +322,7 @@ out: ad_sigma_delta_set_mode(sigma_delta, AD_SD_MODE_IDLE); sigma_delta->bus_locked = false; spi_bus_unlock(sigma_delta->spi->master); - mutex_unlock(&indio_dev->mlock); + iio_device_release_direct_mode(indio_dev);
if (ret) return ret;