[kbuild-all] arch/arm/mach-s3c/gpio-samsung.c:1309:14: warning: no previous prototype for 's3c2410_modify_misccr'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: cd1245d75ce93b8fd206f4b34eb58bcfe156d5e9 commit: 71b9114d2c13a648fbe6523dd859e611c316ad90 ARM: s3c: move into a common directory date: 10 months ago config: arm-randconfig-r031-20210609 (attached as .config) compiler: arm-linux-gnueabi-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 71b9114d2c13a648fbe6523dd859e611c316ad90 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 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 >>): 1309 | unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change) | ^~~~~~~~~~~~~~~~~~~~~ vim +/s3c2410_modify_misccr +1309 arch/arm/mach-s3c/gpio-samsung.c 1b39d5f2cc5c28 drivers/gpio/gpio-samsung.c Kukjin Kim 2011-08-30 1307 1b39d5f2cc5c28 drivers/gpio/gpio-samsung.c Kukjin Kim 2011-08-30 1308 #ifdef CONFIG_PLAT_S3C24XX 1b39d5f2cc5c28 drivers/gpio/gpio-samsung.c Kukjin Kim 2011-08-30 @1309 unsigned int s3c2410_modify_misccr(unsigned int clear, unsigned int change) :::::: The code at line 1309 was first introduced by commit :::::: 1b39d5f2cc5c28085bbf48db80bf704ab4dedda9 gpio/samsung: gpio-samsung.c to support Samsung GPIOs :::::: TO: Kukjin Kim <kgene.kim(a)samsung.com&gt; :::::: CC: Kukjin Kim <kgene.kim(a)samsung.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org