tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 66f4beaa6c1d28161f534471484b2daa2de1dce0 commit: ab5743079b8e3d3d4309664903f6b1f579168a56 MIPS: Get rid of BCM1250_M3_WAR date: 1 year, 2 months ago config: mips-randconfig-r004-20211008 (attached as .config) compiler: mipsel-linux-gcc (GCC) 11.2.0 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 ab5743079b8e3d3d4309664903f6b1f579168a56 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 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 >>): 79 | int sb1250_m3_workaround_needed(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/mips/sibyte/sb1250/setup.c:168:13: warning: no previous prototype for 'sb1250_setup' [-Wmissing-prototypes] 168 | void __init sb1250_setup(void) | ^~~~~~~~~~~~ vim +/sb1250_m3_workaround_needed +79 arch/mips/sibyte/sb1250/setup.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 78 8d9df29db273ab Ralf Baechle 2010-03-23 @79 int sb1250_m3_workaround_needed(void) 8d9df29db273ab Ralf Baechle 2010-03-23 80 { 8d9df29db273ab Ralf Baechle 2010-03-23 81 switch (soc_type) { 8d9df29db273ab Ralf Baechle 2010-03-23 82 case K_SYS_SOC_TYPE_BCM1250: 8d9df29db273ab Ralf Baechle 2010-03-23 83 case K_SYS_SOC_TYPE_BCM1250_ALT: 8d9df29db273ab Ralf Baechle 2010-03-23 84 case K_SYS_SOC_TYPE_BCM1250_ALT2: 8d9df29db273ab Ralf Baechle 2010-03-23 85 case K_SYS_SOC_TYPE_BCM1125: 8d9df29db273ab Ralf Baechle 2010-03-23 86 case K_SYS_SOC_TYPE_BCM1125H: 8d9df29db273ab Ralf Baechle 2010-03-23 87 return soc_pass < K_SYS_REVISION_BCM1250_C0; 8d9df29db273ab Ralf Baechle 2010-03-23 88 8d9df29db273ab Ralf Baechle 2010-03-23 89 default: 8d9df29db273ab Ralf Baechle 2010-03-23 90 return 0; 8d9df29db273ab Ralf Baechle 2010-03-23 91 } 8d9df29db273ab Ralf Baechle 2010-03-23 92 } 8d9df29db273ab Ralf Baechle 2010-03-23 93 :::::: The code at line 79 was first introduced by commit :::::: 8d9df29db273ab9a330828f4f4f6669d293a730a MIPS: Sibyte: Apply M3 workaround only on affected chip types and versions. :::::: TO: Ralf Baechle <ralf(a)linux-mips.org&gt; :::::: CC: Ralf Baechle <ralf(a)linux-mips.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org