On 18/03/17 18:44, 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 buf_lock in the devices global data.
>
> As buf_lock protects both the adis16060_spi_write() and
> adis16060_spi_read() functions and both are always called in
> pair. First write, then read. Thus, refactor the code to have
> one single function adis16060_spi_write_than_read() which is
> protected by the existing buf_lock.
>
> Signed-off-by: simran singhal <singhalsimr...@gmail.com>
Hi Simran,
A couple of minor comments and opportunity to further improve
the, now simpler, code flow.
Thanks,
Jonathan
> ---
>
> v4:
> -Refactored code
> -change commit subject
> -change commit message
>
> drivers/staging/iio/gyro/adis16060_core.c | 37
> ++++++++++++-------------------
> 1 file changed, 14 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c
> b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..39ddd55 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -40,7 +40,7 @@ struct adis16060_state {
>
> static struct iio_dev *adis16060_iio_dev;
>
> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
> +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev, u8 val,
> u16 *val2)
val and val2 often have specific meanings in IIO. I'd prefer these to be
renamed to
val => conf (as it sets the configuration) and val2 => val.
> {
> int ret;
> struct adis16060_state *st = iio_priv(indio_dev);
> @@ -48,17 +48,11 @@ static int adis16060_spi_write(struct iio_dev *indio_dev,
> u8 val)
> mutex_lock(&st->buf_lock);
> st->buf[2] = val; /* The last 8 bits clocked in are latched */
> ret = spi_write(st->us_w, st->buf, 3);
> - mutex_unlock(&st->buf_lock);
>
> - return ret;
> -}
> -
> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
> -{
> - int ret;
> - struct adis16060_state *st = iio_priv(indio_dev);
> -
> - mutex_lock(&st->buf_lock);
> + if (ret < 0) {
> + mutex_unlock(&st->buf_lock);
> + return ret;
> + }
>
> ret = spi_read(st->us_r, st->buf, 3);
>
> @@ -67,10 +61,10 @@ static int adis16060_spi_read(struct iio_dev *indio_dev,
> u16 *val)
> * starts to place data MSB first on the DOUT line at
> * the 6th falling edge of SCLK
> */
> - if (!ret)
> - *val = ((st->buf[0] & 0x3) << 12) |
> - (st->buf[1] << 4) |
> - ((st->buf[2] >> 4) & 0xF);
> + if (!ret)
Please run checkpatch.pl over your patches. Looks like
you ended up with spaces instead of a tab in the line above.
> + *val2 = ((st->buf[0] & 0x3) << 12) |
> + (st->buf[1] << 4) |
> + ((st->buf[2] >> 4) & 0xF);
> mutex_unlock(&st->buf_lock);
>
> return ret;
> @@ -83,20 +77,17 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> {
> u16 tval = 0;
> int ret;
> + struct adis16060_state *st = iio_priv(indio_dev);
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> /* Take the iio_dev status lock */
> - mutex_lock(&indio_dev->mlock);
> - ret = adis16060_spi_write(indio_dev, chan->address);
> + mutex_lock(&st->buf_lock);
> + ret = adis16060_spi_write_than_read(indio_dev, chan->address,
> &tval);
> if (ret < 0)
> goto out_unlock;
>
> - ret = adis16060_spi_read(indio_dev, &tval);
> - if (ret < 0)
This ugly goto construction arguably made sense when there were two of them.
Now
you have only one just bring the mutex_unlock inline and return directly.
> - goto out_unlock;
> -
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->buf_lock);
> *val = tval;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_OFFSET:
> @@ -112,7 +103,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->buf_lock);
> return ret;
> }
>
>
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