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 <lkp@intel.com>]

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	

---
0-DAY CI Kernel Test Service, Intel Corporation
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