drivers/iio/adc/ti-tsc2046.c:242:62: warning: taking address of packed member 'data' of class or structure 'tsc2046_adc_atom' may result in an unaligned pointer value

kernel test robot
2022-01-17T10:01:00Z

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 0c947b893d69231a9add855939da7c66237ab44f
commit: 9374e8f5a38defe90bc65b2decf317c1c62d91dd iio: adc: add ADC driver for the TI TSC2046 controller
date: 8 months ago
config: mips-randconfig-r002-20220116 (https://download.01.org/0day-ci/archive/20220117/202201171718.7ZCI4YeQ-lkp@intel.com/config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c63a3175c2947e8c1a2d3bbe16a8586600705c54)
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
# install mips cross compiling tool for clang build
# apt-get install binutils-mips-linux-gnu
# https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9374e8f5a38defe90bc65b2decf317c1c62d91dd
git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
git fetch --no-tags linus master
git checkout 9374e8f5a38defe90bc65b2decf317c1c62d91dd
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash drivers/iio/adc/ drivers/usb/gadget/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/iio/adc/ti-tsc2046.c:242:62: warning: taking address of packed member 'data' of class or structure 'tsc2046_adc_atom' may result in an unaligned pointer value [-Waddress-of-packed-member]
return FIELD_GET(TI_TSC2046_DATA_12BIT, get_unaligned_be16(&buf->data));
^~~~~~~~~
include/linux/bitfield.h:108:27: note: expanded from macro 'FIELD_GET'
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^~~~
include/linux/bitfield.h:52:38: note: expanded from macro '__BF_FIELD_CHECK'
BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull, \
^~~~
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:328:22: note: expanded from macro 'compiletime_assert'
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~
include/linux/compiler_types.h:316:23: note: expanded from macro '_compiletime_assert'
__compiletime_assert(condition, msg, prefix, suffix)
^~~~~~~~~
include/linux/compiler_types.h:308:9: note: expanded from macro '__compiletime_assert'
if (!(condition)) \
^~~~~~~~~
1 warning generated.

vim +242 drivers/iio/adc/ti-tsc2046.c

239
240 static u16 tsc2046_adc_get_value(struct tsc2046_adc_atom *buf)
241 {
> 242 return FIELD_GET(TI_TSC2046_DATA_12BIT, get_unaligned_be16(&buf->data));
243 }
244

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0-DAY CI Kernel Test Service, Intel Corporation