On 03/12/2017 02:10 PM, simran singhal wrote:
> The IIO subsystem is redefining iio_dev->mlock to be used by
> the IIO core only for protecting device operating mode changes.
> ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
>
> In this driver, mlock was being used to protect hardware state
> changes. Replace it with a lock in the devices global data.
>
> Signed-off-by: simran singhal <singhalsimr...@gmail.com>
> ---
> drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c
> b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..90a3a18 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -29,11 +29,13 @@
> * @us_r: actual spi_device to read back data
> * @buf: transmit or receive buffer
> * @buf_lock: mutex to protect tx and rx
> + * @lock: protect sensor state
> **/
> struct adis16060_state {
> struct spi_device *us_w;
> struct spi_device *us_r;
> struct mutex buf_lock;
> + struct mutex lock; /* protect sensor state */
There should be no need to have two locks here. One should be enough. The
buf_lock protects both the adis16060_spi_write() and adis16060_spi_read()
functions. But both are always called in a pair. First write, then read. You
can refactor the code to have one single function
adis16060_spi_write_than_read() which is protected by the existing buf_lock.
>
> u8 buf[3] ____cacheline_aligned;
> };
> @@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> /* Take the iio_dev status lock */
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = adis16060_spi_write(indio_dev, chan->address);
> if (ret < 0)
> goto out_unlock;
> @@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> goto out_unlock;
>
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> *val = tval;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_OFFSET:
> @@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
>
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