On Mon, 11 Apr 2022 07:18:10 +0000 "Miclaus, Antoniu" <Antoniu.Miclaus@xxxxxxxxxx> wrote: > > -----Original Message----- > > From: Jonathan Cameron <jic23@xxxxxxxxxx> > > Sent: Sunday, April 10, 2022 8:16 PM > > To: linux-iio@xxxxxxxxxxxxxxx > > Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>; Miclaus, Antoniu > > <Antoniu.Miclaus@xxxxxxxxxx> > > Subject: Re: [PATCH] iio: freq: admv1014: Fix warning about dubious x & !y > > and improve readability > > > > [External] > > > > On Sat, 19 Mar 2022 18:14:01 +0000 > > Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > > > > From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > > > > > The warning comes from __BF_FIELD_CHECK() > > > specifically > > > > > > BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ? \ > > > ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \ > > > _pfx "value too large for the field"); \ > > > > > > The code was using !(enum value) which is not particularly easy to follow > > > so replace that with explicit matching and use of ? 0 : 1; or ? 1 : 0; > > > to improve readability. > > > > > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > > Cc: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > > > > Antoniu, or anyone else who has time, can you sanity check this one? > > I'd like to clean up the warning asap but don't really trust myself > > enough to not have done something stupid ;) > > > > Jonathan > > > > > --- > > > drivers/iio/frequency/admv1014.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/iio/frequency/admv1014.c > > b/drivers/iio/frequency/admv1014.c > > > index a7994f8e6b9b..802835efbec7 100644 > > > --- a/drivers/iio/frequency/admv1014.c > > > +++ b/drivers/iio/frequency/admv1014.c > > > @@ -700,8 +700,10 @@ static int admv1014_init(struct admv1014_state > > *st) > > > ADMV1014_DET_EN_MSK; > > > > > > enable_reg = FIELD_PREP(ADMV1014_P1DB_COMPENSATION_MSK, > > st->p1db_comp ? 3 : 0) | > > > - FIELD_PREP(ADMV1014_IF_AMP_PD_MSK, !(st- > > >input_mode)) | > > > - FIELD_PREP(ADMV1014_BB_AMP_PD_MSK, st- > > >input_mode) | > > > + FIELD_PREP(ADMV1014_IF_AMP_PD_MSK, > > > + (st->input_mode == ADMV1014_IQ_MODE) > > ? 0 : 1) | > > > + FIELD_PREP(ADMV1014_BB_AMP_PD_MSK, > > > + (st->input_mode == ADMV1014_IQ_MODE) > > ? 1 : 0) | > Hello Jonathan, > > I think it should be vice-versa: > FIELD_PREP(ADMV1014_IF_AMP_PD_MSK, > (st->input_mode == ADMV1014_IQ_MODE) ? 1 : 0) | > FIELD_PREP(ADMV1014_BB_AMP_PD_MSK, > (st->input_mode == ADMV1014_IQ_MODE) ? 0 : 1) | > > "To set the ADMV1014 in I/Q mode, set BB_AMP_PD > (Register 0x03, Bit 8) to 0 and set IF_AMP_PD (Register 0x03, > Bit 11) to 1." > > "To configure the ADMV1014 in IF mode, set BB_AMP_PD > (Register 0x03, Bit 8) to 1 and set IF_AMP_PD (Register 0x03, > Bit 11) to 0" And that's why I need sanity checks on 'obvious' patches. Thanks! You are correct that I've inverted it by matching on the 0 enum value, whereas the original code was effectively starting with the 1 enum value. Keeping closer to the original code it would be: FIELD_PREP(ADMV1014_IF_AMP_PD_MSK, (st->input_mode == ADMV1014_IF_MODE) ? 0 : 1) | FIELD_PREP(ADMV1014_BB_AMP_PD_MSK, (st->input_mode == ADMV1014_IF_MODE) ? 1 : 0) | I'm tempted to go with that version rather than your equivalent one because it keeps the sense of the statements the same so in theory should be a more obvious patch. Will send a v2. Thanks, Jonathan > > Regards, > > > FIELD_PREP(ADMV1014_DET_EN_MSK, st->det_en); > > > > > > return __admv1014_spi_update_bits(st, ADMV1014_REG_ENABLE, > > enable_reg_msk, enable_reg); >
