tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: c4d6fe7311762f2e03b3c27ad38df7c40c80cc93 commit: 7bc5c428a660d4d1bc95ba54bf4cb6bccf8c3029 dma-direct: remove __dma_to_phys date: 6 weeks ago config: mips-randconfig-r022-20201021 (attached as .config) compiler: mips-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 # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 7bc5c428a660d4d1bc95ba54bf4cb6bccf8c3029 # 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(a)intel.com&gt; All warnings (new ones prefixed by >>): arch/mips/bmips/dma.c:43:12: warning: no previous prototype for '__phys_to_dma' [-Wmissing-prototypes] 43 | dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t pa) | ^~~~~~~~~~~~~ 55 | phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dma_addr) | ^~~~~~~~~~~ arch/mips/bmips/dma.c:67:6: warning: no previous prototype for 'arch_sync_dma_for_cpu_all' [-Wmissing-prototypes] 67 | void arch_sync_dma_for_cpu_all(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~ vim +/dma_to_phys +55 arch/mips/bmips/dma.c 54 56 { 57 struct bmips_dma_range *r; 58 59 for (r = bmips_dma_ranges; r && r->size; r++) { 60 if (dma_addr >= r->parent_addr && 61 dma_addr < (r->parent_addr + r->size)) 62 return dma_addr - r->parent_addr + r->child_addr; 63 } 64 return dma_addr; 65 } 66 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org