tree: https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git devel head: bc9f741e3e9e4828b7bb963e951a24ec7680346c commit: bc13da86df7a60169f8d5e3eca49681bb19f3164 [19/62] tty: tty_flip.h needs only tty_buffer and tty_port config: m68k-allmodconfig (attached as .config) compiler: m68k-linux-gcc (GCC) 10.3.0 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/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 bc13da86df7a60169f8d5e3eca49681bb19f3164 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross O=build_dir ARCH=m68k SHELL=/bin/bash drivers/tty/ 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 >>): In file included from drivers/tty/amiserial.c:59: 43 | int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p, | ^~~~~~~~~ vim +43 include/linux/tty_flip.h 2832fc11f13606 Alan Cox 2010-02-18 42 d4b7b6837b4e64 Jiri Slaby 2021-06-19 @43 int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p, d4b7b6837b4e64 Jiri Slaby 2021-06-19 44 const char *f, int count); d4b7b6837b4e64 Jiri Slaby 2021-06-19 45 :::::: The code at line 43 was first introduced by commit :::::: d4b7b6837b4e648d33d3fa355202d03b2a7e415d tty: move tty_ldisc_receive_buf to tty_flip.h :::::: TO: Jiri Slaby <jslaby(a)suse.cz&gt; :::::: CC: Jiri Slaby <jslaby(a)suse.cz&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org