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 - 07:03:09 EST


On Mon, 2023-11-06 at 12:18 +0100, Alexander Lobakin wrote:
> From: Nuno Sá <noname.nuno@xxxxxxxxx>
> Date: Mon, 06 Nov 2023 11:07:16 +0100
>
> > 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@int
> > > > el
> > > > .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@int
> > > > el
> > > > .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,
>
> assign_bit() does not take a bitmask as a first argument, but a bit number.
>
> I.e. if you want to switch BIT(0), you call it like assign_bit(0, ...),
> not assign_bit(BIT(0), ...). Same for the bit nr 1.
>

Yes, I know... if you look at my reply to Dan you can see I realized that already :)

I guess by the time I first sent this time I didn't knew or maybe just a dumb
mistake...

I'll send a patch later today removing the BIT() from the #define, thx!

- Nuno Sá