On Tue, 25 Jun 2024 18:55:27 -0300 Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx> wrote: > Add support for AD4000 series of low noise, low power, high speed, > successive approximation register (SAR) ADCs. > > Signed-off-by: Marcelo Schmitt <marcelo.schmitt@xxxxxxxxxx> Hi Marcelo, You've clearly gotten some good review for this version so I only had a quick scan through. One thing did jump out at me though. > + > +static int ad4000_write_raw_get_fmt(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, long mask) > +{ > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + return IIO_VAL_INT_PLUS_NANO; > + default: > + return IIO_VAL_INT_PLUS_MICRO; > + } > +} > + > +static int ad4000_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, int val, int val2, > + long mask) > +{ > + struct ad4000_state *st = iio_priv(indio_dev); > + unsigned int reg_val; > + bool span_comp_en; > + int ret; > + > + switch (mask) { > + case IIO_CHAN_INFO_SCALE: > + ret = iio_device_claim_direct_mode(indio_dev); > + if (ret < 0) > + return ret; > + > + mutex_lock(&st->lock); > + ret = ad4000_read_reg(st, ®_val); > + if (ret < 0) > + goto err_unlock; > + > + span_comp_en = val2 == st->scale_tbl[1][1]; > + reg_val &= ~AD4000_CFG_SPAN_COMP; > + reg_val |= FIELD_PREP(AD4000_CFG_SPAN_COMP, span_comp_en); > + > + ret = ad4000_write_reg(st, reg_val); > + if (ret < 0) > + goto err_unlock; > + > + st->span_comp = span_comp_en; > +err_unlock: > + iio_device_release_direct_mode(indio_dev); > + mutex_unlock(&st->lock); Lock ordering needs another look. I'm not sure we an trigger a deadlock but it definitely looks problematic. J