On 7/10/26 6:20 AM, Rodrigo Alencar via B4 Relay wrote:
> From: Rodrigo Alencar <[email protected]>
>
> Use guarded mutex lock to facilitate code review when adding new
> attributes. This will allow for early returns, avoiding error-prone
> locking and unlocking in error paths. This also adds missing include
> linux/cleanup.h. Gain-control support will allow the scale attribute
> to be configurable.
>
> Reviewed-by: Maxwell Doose <[email protected]>
> Reviewed-by: Joshua Crofts <[email protected]>
> Signed-off-by: Rodrigo Alencar <[email protected]>
> ---
> drivers/iio/dac/ad5686.c | 19 ++++++++-----------
> 1 file changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
> index 316f9ccf54d9..df32f46db81e 100644
> --- a/drivers/iio/dac/ad5686.c
> +++ b/drivers/iio/dac/ad5686.c
> @@ -8,6 +8,7 @@
> #include <linux/array_size.h>
> #include <linux/bitfield.h>
> #include <linux/bitops.h>
> +#include <linux/cleanup.h>
> #include <linux/delay.h>
> #include <linux/dev_printk.h>
> #include <linux/errno.h>
> @@ -177,11 +178,11 @@ static int ad5686_read_raw(struct iio_dev *indio_dev,
> struct ad5686_state *st = iio_priv(indio_dev);
> int ret;
>
> + guard(mutex)(&st->lock);
The commit message should explain why the location we are taking the lock
has moved. Although, I don't see a reason to move it.
> +
> switch (m) {
> case IIO_CHAN_INFO_RAW:
> - mutex_lock(&st->lock);
> ret = ad5686_read(st, chan->address);
> - mutex_unlock(&st->lock);
> if (ret < 0)
> return ret;
> *val = (ret >> chan->scan_type.shift) &
> @@ -202,23 +203,19 @@ static int ad5686_write_raw(struct iio_dev *indio_dev,
> long mask)
> {
> struct ad5686_state *st = iio_priv(indio_dev);
> - int ret;
> +
> + guard(mutex)(&st->lock);
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> if (val >= (1 << chan->scan_type.realbits) || val < 0)
> return -EINVAL;
>
> - mutex_lock(&st->lock);
> - ret = ad5686_write(st, AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
> - chan->address, val << chan->scan_type.shift);
> - mutex_unlock(&st->lock);
> - break;
> + return ad5686_write(st, AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
> + chan->address, val <<
> chan->scan_type.shift);
> default:
> - ret = -EINVAL;
> + return -EINVAL;
> }
> -
> - return ret;
> }
>
> static const struct iio_info ad5686_info = {
>
