tree: https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git devel head: 0ecc0cdeaabd6b08ef3ec6dfaf724139031c00b8 commit: 2258e16ea4fe67f9700294b439b7aa1669aef643 [10/31] serial: make uart_console_write->putchar's character a char config: nds32-randconfig-r023-20220116 (https://download.01.org/0day-ci/archive/20220119/202201190244.I2BjsDwz-lk...) compiler: nds32le-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/jirislaby/linux.git/commi... git remote add jirislaby https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git git fetch --no-tags jirislaby devel git checkout 2258e16ea4fe67f9700294b439b7aa1669aef643 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=nds32 SHELL=/bin/bash drivers/tty/serial/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/tty/serial/samsung_tty.c: In function 'samsung_early_write': 2983 | uart_console_write(&dev->port, s, n, samsung_early_putc); | ^~~~~~~~~~~~~~~~~~ | | | void (*)(struct uart_port *, int) In file included from drivers/tty/serial/samsung_tty.c:36: include/linux/serial_core.h:402:32: note: expected 'void (*)(struct uart_port *, char)' but argument is of type 'void (*)(struct uart_port *, int)' 402 | void (*putchar)(struct uart_port *, char)); | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/uart_console_write +2983 drivers/tty/serial/samsung_tty.c b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2977 90ece856a227c4 drivers/tty/serial/samsung_tty.c Greg Kroah-Hartman 2019-12-10 2978 static void samsung_early_write(struct console *con, const char *s, 90ece856a227c4 drivers/tty/serial/samsung_tty.c Greg Kroah-Hartman 2019-12-10 2979 unsigned int n) b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2980 { b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2981 struct earlycon_device *dev = con->data; b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2982 b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 @2983 uart_console_write(&dev->port, s, n, samsung_early_putc); b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2984 } b94ba0328d3b36 drivers/tty/serial/samsung.c Tomasz Figa 2015-01-23 2985 :::::: The code at line 2983 was first introduced by commit :::::: b94ba0328d3b36ff95f5074c0e9b44f90dc56bb5 serial: samsung: Add support for early console :::::: TO: Tomasz Figa <t.figa(a)samsung.com&gt; :::::: CC: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org