tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   889bab4c367a0ef58208fd80fafa74bb6e2dca26
commit: de5473936808627fa98c3d2e8e3fa3076338f601 [11572/11714] mbox: add polarfire soc system controller mailbox
config: arm-randconfig-r032-20210621 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e1adf90826a57b674eee79b071fb46c1f5683cd0)
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 arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=de5473936808627fa98c3d2e8e3fa3076338f601
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout de5473936808627fa98c3d2e8e3fa3076338f601
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

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 >>):

   In file included from drivers/mailbox/mailbox-mpfs.c:19:
>> include/soc/microchip/mpfs.h:49:29: warning: no previous prototype for function 'mpfs_sys_controller_get' [-Wmissing-prototypes]
   struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
                               ^
   include/soc/microchip/mpfs.h:49:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
   ^
   static 
>> drivers/mailbox/mailbox-mpfs.c:122:43: warning: shift count >= width of type [-Wshift-count-overflow]
           tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
                                                    ^~~~~~~~~~~~~
   drivers/mailbox/mailbox-mpfs.c:42:23: note: expanded from macro 'SCB_CTRL_MASK'
   #define SCB_CTRL_MASK GENMASK(SCB_CTRL_POS + SCB_MASK_WIDTH, SCB_CTRL_POS)
                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/bits.h:38:31: note: expanded from macro 'GENMASK'
           (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
                                        ^~~~~~~~~~~~~~~
   include/linux/bits.h:36:11: note: expanded from macro '__GENMASK'
            (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
                    ^  ~~~~~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/mailbox/mailbox-mpfs.c:19:
   include/soc/microchip/mpfs.h:43:12: warning: unused function 'mpfs_blocking_transaction' [-Wunused-function]
   static int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg,
              ^
   3 warnings generated.

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for QCOM_SCM
   Depends on (ARM || ARM64) && HAVE_ARM_SMCCC
   Selected by
   - ARM_QCOM_SPM_CPUIDLE && CPU_IDLE && (ARM || ARM64) && (ARCH_QCOM || COMPILE_TEST && !ARM64 && MMU


vim +/mpfs_sys_controller_get +49 include/soc/microchip/mpfs.h

    48	
  > 49	struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
    50	{
    51		return NULL;
    52	}
    53	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org