[miquelraynal:renesas/0-day/uart-dma 15/16] ERROR: modpost: "serial8250_rx_dma" [drivers/tty/serial/8250/8250_dw.ko] undefined!

[kernel test robot]

tree:   https://github.com/miquelraynal/linux-0day.git renesas/0-day/uart-dma
head:   cac854e8b055133a489d6aa5ca301cabaf4721a0
commit: 27904fce5a96f06bd80cd303a511ef7c2e9cc11b [15/16] serial: 8250_dw: Add support for RZ/N1 DMA
config: x86_64-randconfig-a005 (https://download.01.org/0day-ci/archive/20220224/202202240719.lGPmYS8a-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
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://github.com/miquelraynal/linux-0day/commit/27904fce5a96f06bd80cd303a511ef7c2e9cc11b
        git remote add miquelraynal https://github.com/miquelraynal/linux-0day.git
        git fetch --no-tags miquelraynal renesas/0-day/uart-dma
        git checkout 27904fce5a96f06bd80cd303a511ef7c2e9cc11b
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "serial8250_rx_dma" [drivers/tty/serial/8250/8250_dw.ko] undefined!
>> ERROR: modpost: "serial8250_tx_dma" [drivers/tty/serial/8250/8250_dw.ko] undefined!

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx