On Tue, May 24, 2016 at 10:17 PM, Alison Schofield <amsfield22@xxxxxxxxx> wrote:
> Driver was checking for direct mode and trying to lock it, but
> left a gap where mode could change before the desired operation.
> Use iio_device_claim_direct_mode() to guarantee device stays in
> direct mode.
>
> Signed-off-by: Alison Schofield <amsfield22@xxxxxxxxx>
> Cc: Daniel Baluta <daniel.baluta@xxxxxxxxx>
Acked-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> ---
> drivers/iio/adc/ad7793.c | 13 ++++---------
> 1 file changed, 4 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/iio/adc/ad7793.c b/drivers/iio/adc/ad7793.c
> index 7b07bb6..3f41cd8 100644
> --- a/drivers/iio/adc/ad7793.c
> +++ b/drivers/iio/adc/ad7793.c
> @@ -369,13 +369,6 @@ static ssize_t ad7793_write_frequency(struct device *dev,
> long lval;
> int i, ret;
>
> - mutex_lock(&indio_dev->mlock);
> - if (iio_buffer_enabled(indio_dev)) {
> - mutex_unlock(&indio_dev->mlock);
> - return -EBUSY;
> - }
> - mutex_unlock(&indio_dev->mlock);
> -
> ret = kstrtol(buf, 10, &lval);
> if (ret)
> return ret;
> @@ -387,12 +380,14 @@ static ssize_t ad7793_write_frequency(struct device *dev,
>
> for (i = 0; i < 16; i++)
> if (lval == st->chip_info->sample_freq_avail[i]) {
> - mutex_lock(&indio_dev->mlock);
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
> st->mode &= ~AD7793_MODE_RATE(-1);
> st->mode |= AD7793_MODE_RATE(i);
> ad_sd_write_reg(&st->sd, AD7793_REG_MODE,
> sizeof(st->mode), st->mode);
> - mutex_unlock(&indio_dev->mlock);
> + iio_device_release_direct_mode(indio_dev);
> ret = 0;
> }
>
> --
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
