Re: [PATCH v6 6/7] iio: light: ROHM BU27034 Ambient Light Sensor

kernel test robot
2023-03-28T06:00:00Z

Hi Matti,

I love your patch! Perhaps something to improve:

[auto build test WARNING on eeac8ede17557680855031c6f305ece2378af326]

url: https://github.com/intel-lab-lkp/linux/commits/Matti-Vaittinen/dt-bindings-iio-light-Support-ROHM-BU27034/20230327-193728
base: eeac8ede17557680855031c6f305ece2378af326
patch link: https://lore.kernel.org/r/1b7d3725bf5ae829b12eaf96362204edd29c6966.1679915278.git.mazziesaccount%40gmail.com
patch subject: [PATCH v6 6/7] iio: light: ROHM BU27034 Ambient Light Sensor
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20230328/202303281338.X45nIbaD-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/b824935db7c7734628f11c55cd64dc819be8798f
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Matti-Vaittinen/dt-bindings-iio-light-Support-ROHM-BU27034/20230327-193728
git checkout b824935db7c7734628f11c55cd64dc819be8798f
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/iio/light/ drivers/media/i2c/ drivers/media/pci/intel/ drivers/net/usb/ net/netfilter/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303281338.X45nIbaD-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/iio/light/rohm-bu27034.c:402:8: warning: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((mask), char: (unsigned char)0, unsigned char: (unsigned char)0, signed char: (unsigned char)0, unsigned short: (unsigned short)0, short: (unsigned short)0, unsigned int: (unsigned int)0, int: (unsigned int)0, unsigned long: (unsigned long)0, long: (unsigned long)0, unsigned long long: (unsigned long long)0, long long: (unsigned long long)0, default: (mask)))' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
val = FIELD_PREP(mask, sel);
^~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:114:3: note: expanded from macro 'FIELD_PREP'
__BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: "); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:71:53: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) > \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
include/linux/build_bug.h:39:58: note: expanded from macro 'BUILD_BUG_ON_MSG'
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
include/linux/compiler_types.h:397:22: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler_types.h:385:23: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/compiler_types.h:377:9: note: expanded from macro '__compiletime_assert'
if (!(condition)) \
^~~~~~~~~
1 warning generated.

vim +402 drivers/iio/light/rohm-bu27034.c

388
389 /* Caller should hold the lock to protect lux reading */
390 static int bu27034_write_gain_sel(struct bu27034_data *data, int chan, int sel)
391 {
392 static const int reg[] = {
393 [BU27034_CHAN_DATA0] = BU27034_REG_MODE_CONTROL2,
394 [BU27034_CHAN_DATA1] = BU27034_REG_MODE_CONTROL3,
395 };
396 int mask, val;
397
398 if (chan != BU27034_CHAN_DATA0 && chan != BU27034_CHAN_DATA1)
399 return -EINVAL;
400
401 mask = BU27034_MASK_D01_GAIN;
> 402 val = FIELD_PREP(mask, sel);
403
404 if (chan == BU27034_CHAN_DATA0) {
405 /*
406 * We keep the same gain for channel 2 as we set for channel 0
407 * We can't allow them to be individually controlled because
408 * setting one will impact also the other. Also, if we don't
409 * always update both gains we may result unsupported bit
410 * combinations.
411 *
412 * This is not nice but this is yet another place where the
413 * user space must be prepared to surprizes. Namely, see chan 2
414 * gain changed when chan 0 gain is changed.
415 *
416 * This is not fatal for most users though. I don't expect the
417 * channel 2 to be used in any generic cases - the intensity
418 * values provided by the sensor for IR area are not openly
419 * documented. Also, channel 2 is not used for visible light.
420 *
421 * So, if there is application which is written to utilize the
422 * channel 2 - then it is probably specifically targeted to this
423 * sensor and knows how to utilize those values. It is safe to
424 * hope such user can also cope with the gain changes.
425 */
426 mask |= BU27034_MASK_D2_GAIN_LO;
427
428 /*
429 * The D2 gain bits are directly the lowest bits of selector.
430 * Just do add those bits to the value
431 */
432 val |= sel & BU27034_MASK_D2_GAIN_LO;
433 }
434
435 return regmap_update_bits(data->regmap, reg[chan], mask, val);
436 }
437

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