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* drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
@ 2024-01-10 17:53 kernel test robot
  0 siblings, 0 replies; 4+ messages in thread
From: kernel test robot @ 2024-01-10 17:53 UTC (permalink / raw)
  To: Aidan MacDonald
  Cc: oe-kbuild-all, linux-kernel, Jonathan Cameron, Chen-Yu Tsai,
	Andy Shevchenko

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   ab27740f76654ed58dd32ac0ba0031c18a6dea3b
commit: 8957e5344353e9cd3f6b1e3004942e35449fa0e8 iio: adc: axp20x_adc: Minor code cleanups
date:   10 months ago
config: csky-buildonly-randconfig-r006-20230413 (https://download.01.org/0day-ci/archive/20240111/202401110159.j4qEZUPp-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20240111/202401110159.j4qEZUPp-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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401110159.j4qEZUPp-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
   drivers/iio/adc/axp20x_adc.c:577:26: sparse: sparse: dubious: x & !y
   drivers/iio/adc/axp20x_adc.c: note: in included file (through include/linux/mmzone.h, include/linux/topology.h, include/linux/irq.h, ...):
   include/linux/page-flags.h:246:46: sparse: sparse: self-comparison always evaluates to false

vim +572 drivers/iio/adc/axp20x_adc.c

   551	
   552	static int axp20x_write_raw(struct iio_dev *indio_dev,
   553				    struct iio_chan_spec const *chan, int val, int val2,
   554				    long mask)
   555	{
   556		struct axp20x_adc_iio *info = iio_priv(indio_dev);
   557		unsigned int regmask, regval;
   558	
   559		/*
   560		 * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
   561		 * for (independently) GPIO0 and GPIO1 when in ADC mode.
   562		 */
   563		if (mask != IIO_CHAN_INFO_OFFSET)
   564			return -EINVAL;
   565	
   566		if (val != 0 && val != 700000)
   567			return -EINVAL;
   568	
   569		switch (chan->channel) {
   570		case AXP20X_GPIO0_V:
   571			regmask = AXP20X_GPIO10_IN_RANGE_GPIO0;
 > 572			regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO0, !!val);
   573			break;
   574	
   575		case AXP20X_GPIO1_V:
   576			regmask = AXP20X_GPIO10_IN_RANGE_GPIO1;
   577			regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO1, !!val);
   578			break;
   579	
   580		default:
   581			return -EINVAL;
   582		}
   583	
   584		return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, regmask, regval);
   585	}
   586	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
  2024-01-07  5:37 ` Chen-Yu Tsai
@ 2024-01-07 19:46   ` Andy Shevchenko
  0 siblings, 0 replies; 4+ messages in thread
From: Andy Shevchenko @ 2024-01-07 19:46 UTC (permalink / raw)
  To: wens
  Cc: kernel test robot, Aidan MacDonald, oe-kbuild-all, linux-kernel,
	Jonathan Cameron

On Sun, Jan 7, 2024 at 7:37 AM Chen-Yu Tsai <wens@csie.org> wrote:
> On Sun, Jan 7, 2024 at 9:30 AM kernel test robot <lkp@intel.com> wrote:

...

> > sparse warnings: (new ones prefixed by >>)
> > >> drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
> >    drivers/iio/adc/axp20x_adc.c:577:26: sparse: sparse: dubious: x & !y
>
> This looks like a false positive. The code is doing exactly what we want:
> val = val ? 1 : 0, but in a shorter format.

Yes, but the problem is that FIELD_PREP() is a macro.
You can replace these by ternary (here and in other cases) to satisfy
sparse. Compiler will optimize that anyway, so no branch is expected
in the generated code.

-- 
With Best Regards,
Andy Shevchenko

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
  2024-01-07  1:28 kernel test robot
@ 2024-01-07  5:37 ` Chen-Yu Tsai
  2024-01-07 19:46   ` Andy Shevchenko
  0 siblings, 1 reply; 4+ messages in thread
From: Chen-Yu Tsai @ 2024-01-07  5:37 UTC (permalink / raw)
  To: kernel test robot
  Cc: Aidan MacDonald, oe-kbuild-all, linux-kernel, Jonathan Cameron,
	Andy Shevchenko

On Sun, Jan 7, 2024 at 9:30 AM kernel test robot <lkp@intel.com> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   52b1853b080a082ec3749c3a9577f6c71b1d4a90
> commit: 8957e5344353e9cd3f6b1e3004942e35449fa0e8 iio: adc: axp20x_adc: Minor code cleanups
> date:   10 months ago
> config: x86_64-randconfig-121-20240106 (https://download.01.org/0day-ci/archive/20240107/202401070901.68H00NFa-lkp@intel.com/config)
> compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240107/202401070901.68H00NFa-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@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202401070901.68H00NFa-lkp@intel.com/
>
> sparse warnings: (new ones prefixed by >>)
> >> drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
>    drivers/iio/adc/axp20x_adc.c:577:26: sparse: sparse: dubious: x & !y

This looks like a false positive. The code is doing exactly what we want:
val = val ? 1 : 0, but in a shorter format.

ChenYu

>
> vim +572 drivers/iio/adc/axp20x_adc.c
>
>    551
>    552  static int axp20x_write_raw(struct iio_dev *indio_dev,
>    553                              struct iio_chan_spec const *chan, int val, int val2,
>    554                              long mask)
>    555  {
>    556          struct axp20x_adc_iio *info = iio_priv(indio_dev);
>    557          unsigned int regmask, regval;
>    558
>    559          /*
>    560           * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
>    561           * for (independently) GPIO0 and GPIO1 when in ADC mode.
>    562           */
>    563          if (mask != IIO_CHAN_INFO_OFFSET)
>    564                  return -EINVAL;
>    565
>    566          if (val != 0 && val != 700000)
>    567                  return -EINVAL;
>    568
>    569          switch (chan->channel) {
>    570          case AXP20X_GPIO0_V:
>    571                  regmask = AXP20X_GPIO10_IN_RANGE_GPIO0;
>  > 572                  regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO0, !!val);
>    573                  break;
>    574
>    575          case AXP20X_GPIO1_V:
>    576                  regmask = AXP20X_GPIO10_IN_RANGE_GPIO1;
>    577                  regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO1, !!val);
>    578                  break;
>    579
>    580          default:
>    581                  return -EINVAL;
>    582          }
>    583
>    584          return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, regmask, regval);
>    585  }
>    586
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 4+ messages in thread

* drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
@ 2024-01-07  1:28 kernel test robot
  2024-01-07  5:37 ` Chen-Yu Tsai
  0 siblings, 1 reply; 4+ messages in thread
From: kernel test robot @ 2024-01-07  1:28 UTC (permalink / raw)
  To: Aidan MacDonald
  Cc: oe-kbuild-all, linux-kernel, Jonathan Cameron, Chen-Yu Tsai,
	Andy Shevchenko

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   52b1853b080a082ec3749c3a9577f6c71b1d4a90
commit: 8957e5344353e9cd3f6b1e3004942e35449fa0e8 iio: adc: axp20x_adc: Minor code cleanups
date:   10 months ago
config: x86_64-randconfig-121-20240106 (https://download.01.org/0day-ci/archive/20240107/202401070901.68H00NFa-lkp@intel.com/config)
compiler: ClangBuiltLinux clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240107/202401070901.68H00NFa-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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401070901.68H00NFa-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y
   drivers/iio/adc/axp20x_adc.c:577:26: sparse: sparse: dubious: x & !y

vim +572 drivers/iio/adc/axp20x_adc.c

   551	
   552	static int axp20x_write_raw(struct iio_dev *indio_dev,
   553				    struct iio_chan_spec const *chan, int val, int val2,
   554				    long mask)
   555	{
   556		struct axp20x_adc_iio *info = iio_priv(indio_dev);
   557		unsigned int regmask, regval;
   558	
   559		/*
   560		 * The AXP20X PMIC allows the user to choose between 0V and 0.7V offsets
   561		 * for (independently) GPIO0 and GPIO1 when in ADC mode.
   562		 */
   563		if (mask != IIO_CHAN_INFO_OFFSET)
   564			return -EINVAL;
   565	
   566		if (val != 0 && val != 700000)
   567			return -EINVAL;
   568	
   569		switch (chan->channel) {
   570		case AXP20X_GPIO0_V:
   571			regmask = AXP20X_GPIO10_IN_RANGE_GPIO0;
 > 572			regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO0, !!val);
   573			break;
   574	
   575		case AXP20X_GPIO1_V:
   576			regmask = AXP20X_GPIO10_IN_RANGE_GPIO1;
   577			regval = FIELD_PREP(AXP20X_GPIO10_IN_RANGE_GPIO1, !!val);
   578			break;
   579	
   580		default:
   581			return -EINVAL;
   582		}
   583	
   584		return regmap_update_bits(info->regmap, AXP20X_GPIO10_IN_RANGE, regmask, regval);
   585	}
   586	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2024-01-10 17:54 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2024-01-10 17:53 drivers/iio/adc/axp20x_adc.c:572:26: sparse: sparse: dubious: x & !y kernel test robot
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2024-01-07  1:28 kernel test robot
2024-01-07  5:37 ` Chen-Yu Tsai
2024-01-07 19:46   ` Andy Shevchenko

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