Hi Li-hao,

I love your patch! Yet something to improve:

[auto build test ERROR on broonie-spi/for-next]
[also build test ERROR on pza/reset/next robh/for-next linus/master v5.16]
[cannot apply to next-20220110]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Li-hao-Kuo/Add-SPI-control-driver-for-Sunplus-SP7021-SoC/20220110-144745
base:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
config: alpha-allyesconfig (https://download.01.org/0day-ci/archive/20220110/202201101911.hSqY5DkA-lkp@intel.com/config)
compiler: alpha-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://github.com/0day-ci/linux/commit/53da1eda2d6e7a04e09dcb37a029ec3b384b7afb
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Li-hao-Kuo/Add-SPI-control-driver-for-Sunplus-SP7021-SoC/20220110-144745
        git checkout 53da1eda2d6e7a04e09dcb37a029ec3b384b7afb
        # 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=alpha SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

>> make[3]: *** No rule to make target 'drivers/spi/spi-sunplus-sp7021.o', needed by 'drivers/spi/built-in.a'.
   make[3]: Target '__build' not remade because of errors.

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