4.9-stable review patch. If anyone has any objections, please let me know.
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From: Alison Schofield amsfield22@gmail.com
[ Upstream commit 3bc1abcddb24f55b9c251e03caa4f9bd22ff748b ]
Driver was checking for direct mode before changing oversampling ratios, but was not locking it. Use the claim/release helper functions to guarantee the device stays in direct mode while the oversampling ratios are being updated. Continue to use the drivers private state lock to protect against conflicting direct mode access of the state data.
Signed-off-by: Alison Schofield amsfield22@gmail.com Signed-off-by: Jonathan Cameron jic23@kernel.org Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/pressure/ms5611_core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/iio/pressure/ms5611_core.c +++ b/drivers/iio/pressure/ms5611_core.c @@ -308,6 +308,7 @@ static int ms5611_write_raw(struct iio_d { struct ms5611_state *st = iio_priv(indio_dev); const struct ms5611_osr *osr = NULL; + int ret;
if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO) return -EINVAL; @@ -321,12 +322,11 @@ static int ms5611_write_raw(struct iio_d if (!osr) return -EINVAL;
- mutex_lock(&st->lock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret;
- if (iio_buffer_enabled(indio_dev)) { - mutex_unlock(&st->lock); - return -EBUSY; - } + mutex_lock(&st->lock);
if (chan->type == IIO_TEMP) st->temp_osr = osr; @@ -334,6 +334,8 @@ static int ms5611_write_raw(struct iio_d st->pressure_osr = osr;
mutex_unlock(&st->lock); + iio_device_release_direct_mode(indio_dev); + return 0; }