From 3d36da392191dca16b60f40af4a4259be279abac Mon Sep 17 00:00:00 2001 From: =?utf8?q?Nuno=20S=C3=A1?= Date: Tue, 20 Sep 2022 13:28:07 +0200 Subject: [PATCH] iio: adc: ad_sigma_delta: do not use internal iio_dev lock MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: 73ddaa6b2f8a ("iio:adc: Add common code for ADI Sigma Delta devices") Signed-off-by: Nuno Sá Reviewed-by: Miquel Raynal Cc: #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 Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/ad_sigma_delta.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c index 2640b75fb774c..a2171c887561e 100644 --- a/drivers/iio/adc/ad_sigma_delta.c +++ b/drivers/iio/adc/ad_sigma_delta.c @@ -283,10 +283,10 @@ int ad_sigma_delta_single_conversion(struct iio_dev *indio_dev, 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); @@ -325,7 +325,7 @@ 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; -- 2.39.5