tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   d52daa8620c65960e1ef882adc1f92061326bd7a
commit: 7505576d1c1ac0cfe85fdf90999433dd8b673012 MIPS: add support for SGI Octane (IP30)
date:   9 months ago
config: mips-randconfig-r014-20200802 (attached as .config)
compiler: mips64-linux-gcc (GCC) 9.3.0
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
        git checkout 7505576d1c1ac0cfe85fdf90999433dd8b673012
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 

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 >>):

>> arch/mips/sgi-ip30/ip30-setup.c:122:13: warning: no previous prototype for 'plat_mem_setup' [-Wmissing-prototypes]
     122 | void __init plat_mem_setup(void)
         |             ^~~~~~~~~~~~~~

vim +/plat_mem_setup +122 arch/mips/sgi-ip30/ip30-setup.c

   118	
   119	/**
   120	 * plat_mem_setup - despite the name, misc setup happens here.
   121	 */
 > 122	void __init plat_mem_setup(void)
   123	{
   124		ip30_mem_init();
   125	
   126		/* XXX: Hard lock on /sbin/init if this flag isn't specified. */
   127		prom_flags |= PROM_FLAG_DONT_FREE_TEMP;
   128	

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