Re: [alobakin:pfcp 5/20] drivers/iio/imu/adis16475.c:363 adis16475_set_freq() warn: set_bit() takes a bit number

From: Nuno Sá
Date: Mon Nov 06 2023 - 05:07:23 EST


Hi Olek,

On Mon, 2023-11-06 at 10:31 +0100, Alexander Lobakin wrote:
> From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Date: Mon, 6 Nov 2023 11:50:03 +0300
>
> Hi,
>
> > tree:   https://github.com/alobakin/linux pfcp
> > head:   89565e300e3d4033b8bb568774804fdc09d4f3cc
> > commit: 945a0d6e86d97bf60f2fae88ee557ed3eae18b94 [5/20] bitops: let the compiler
> > optimize {__,}assign_bit()
> > config: i386-randconfig-141-20231105
> > (https://download.01.org/0day-ci/archive/20231106/202311060647.i9XyO4ej-lkp@intel
> > .com/config)
> > compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> > reproduce:
> > (https://download.01.org/0day-ci/archive/20231106/202311060647.i9XyO4ej-lkp@intel
> > .com/reproduce)
> >
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > > Closes: https://lore.kernel.org/r/202311060647.i9XyO4ej-lkp@xxxxxxxxx/
> >
> > smatch warnings:
> > drivers/iio/imu/adis16475.c:363 adis16475_set_freq() warn: set_bit() takes a bit
> > number
> > drivers/iio/imu/adis16475.c:363 adis16475_set_freq() warn: clear_bit() takes a
> > bit number
> > drivers/iio/imu/adis16475.c:416 adis16475_set_filter() warn: set_bit() takes a
> > bit number
> > drivers/iio/imu/adis16475.c:416 adis16475_set_filter() warn: clear_bit() takes a
> > bit number
> >
> > vim +363 drivers/iio/imu/adis16475.c
> >
> > fff7352bf7a3ce Nuno Sá 2020-04-13  357 
> > 9da1b86865ab43 Nuno Sá 2021-09-20  358          adis_dev_unlock(&st->adis);
> > fff7352bf7a3ce Nuno Sá 2020-04-13  359          /*
> > fff7352bf7a3ce Nuno Sá 2020-04-13  360           * If decimation is used, then
> > gyro and accel data will have meaningful
> > fff7352bf7a3ce Nuno Sá 2020-04-13  361           * bits on the LSB registers.
> > This info is used on the trigger handler.
> > fff7352bf7a3ce Nuno Sá 2020-04-13  362           */
> > fff7352bf7a3ce Nuno Sá 2020-04-13
> > @363          assign_bit(ADIS16475_LSB_DEC_MASK, &st->lsb_flag, dec);
> >
> > assign_bit() takes a bit number like 0.  But this is passing BIT(0) so
> > it's like BIT(BIT(0)).  Which is fine until you get to 5.
>
> Is this intended? There are 2 places where you pass
> %ADIS16475_LSB_DEC_MASK and %ADIS16475_LSB_FIR_MASK, which is `BIT(0)`
> and `BIT(1)` respectively, to assign_bit(), which takes 0, 1 etc.
>

Sorry, I'm missing the point in here... This should be a simple mask as 
GENMASK(1, 0) setting/clearing the bits when appropriate. Obviously,
ADIS16475_LSB_DEC_MASK and ADIS16475_LSB_FIR_MASK are not properly defined
:sweat_smile:

- Nuno Sá
>
> >