> > @@ -436,10 +431,10 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev,
> > if (chan->output == 0)
> > return -EINVAL;
> >
> > - /* Locking not required as writing single value */
> > - mutex_lock(&st->lock);
> > - st->dac_val = val;
> > - mutex_unlock(&st->lock);
> > + scoped_guard(mutex, &st->lock) {
> > + /* Locking not required as writing single value */
> > + st->dac_val = val;
> > + }
> > return 0;
> > default:
> > return -EINVAL;
> > @@ -447,9 +442,9 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev,
> > case IIO_CHAN_INFO_PROCESSED:
> > switch (chan->type) {
> > case IIO_STEPS:
> > - mutex_lock(&st->lock);
> > - st->steps = val;
> > - mutex_unlock(&st->lock);
> > + scoped_guard(mutex, &st->lock) {
> > + st->steps = val;
> > + }
> > return 0;
> > case IIO_ACTIVITY:
> > if (val < 0)
> > @@ -470,30 +465,29 @@ static int iio_dummy_write_raw(struct iio_dev *indio_dev,
> > default:
> > return -EINVAL;
> > }
> > - case IIO_CHAN_INFO_CALIBSCALE:
> > - mutex_lock(&st->lock);
> > + case IIO_CHAN_INFO_CALIBSCALE: {
> > + guard(mutex)(&st->lock);
> > /* Compare against table - hard matching here */
> > for (i = 0; i < ARRAY_SIZE(dummy_scales); i++)
> > if (val == dummy_scales[i].val &&
> > val2 == dummy_scales[i].val2)
> > break;
> > if (i == ARRAY_SIZE(dummy_scales))
> > - ret = -EINVAL;
> > - else
> > - st->accel_calibscale = &dummy_scales[i];
> > - mutex_unlock(&st->lock);
> > + return -EINVAL;
> > + st->accel_calibscale = &dummy_scales[i];
> > return ret;
>
> Can we change this to `return 0;` and get rid of the `ret = 0`
> initialization at the beginning of the function?
Yes. That would make sense.
>
> > + }
