Hi,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on tty/tty-testing]
[also build test WARNING on linus/master v6.0-rc4 next-20220906]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/matthew-gerlach-linux-intel-com/Enhance-definition-of-DFH-and-use-enhancements-for-uart-driver/20220907-030745
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
config: m68k-allmodconfig
compiler: m68k-linux-gcc (GCC) 12.1.0
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/intel-lab-lkp/linux/commit/0789c6e3047216c8a58a9ec723e100b1293633c6
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review matthew-gerlach-linux-intel-com/Enhance-definition-of-DFH-and-use-enhancements-for-uart-driver/20220907-030745
        git checkout 0789c6e3047216c8a58a9ec723e100b1293633c6
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/tty/serial/8250/

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

All warnings (new ones prefixed by >>):

>> drivers/tty/serial/8250/8250_dfl.c:33:5: warning: no previous prototype for 'feature_uart_walk' [-Wmissing-prototypes]
      33 | int feature_uart_walk(struct dfl_uart *dfluart, resource_size_t max)
         |     ^~~~~~~~~~~~~~~~~


vim +/feature_uart_walk +33 drivers/tty/serial/8250/8250_dfl.c

    32	
  > 33	int feature_uart_walk(struct dfl_uart *dfluart, resource_size_t max)
    34	{
    35		void __iomem *param_base;
    36		int off;
    37		u64 v;
    38	
    39		v = readq(dfluart->csr_base + DFHv1_CSR_ADDR);
    40		dfluart->csr_addr = FIELD_GET(DFHv1_CSR_ADDR_MASK, v);
    41	
    42		v = readq(dfluart->csr_base + DFHv1_CSR_SIZE_GRP);
    43		dfluart->csr_size = FIELD_GET(DFHv1_CSR_SIZE_GRP_SIZE, v);
    44	
    45		if (dfluart->csr_addr == 0 || dfluart->csr_size == 0) {
    46			dev_err(dfluart->dev, "FIXME bad dfh address and size\n");
    47			return -EINVAL;
    48		}
    49	
    50		if (!FIELD_GET(DFHv1_CSR_SIZE_GRP_HAS_PARAMS, v)) {
    51			dev_err(dfluart->dev, "missing required parameters\n");
    52			return -EINVAL;
    53		}
    54	
    55		param_base = dfluart->csr_base + DFHv1_PARAM_HDR;
    56	
    57		off = dfl_find_param(param_base, max, DFHv1_PARAM_ID_CLK_FRQ);
    58		if (off < 0) {
    59			dev_err(dfluart->dev, "missing CLK_FRQ param\n");
    60			return -EINVAL;
    61		}
    62	
    63		dfluart->uart_clk = readq(param_base + off + DFHv1_PARAM_DATA);
    64		dev_dbg(dfluart->dev, "UART_CLK_ID %llu Hz\n", dfluart->uart_clk);
    65	
    66		off = dfl_find_param(param_base, max, DFHv1_PARAM_ID_FIFO_LEN);
    67		if (off < 0) {
    68			dev_err(dfluart->dev, "missing FIFO_LEN param\n");
    69			return -EINVAL;
    70		}
    71	
    72		dfluart->fifo_len = readq(param_base + off + DFHv1_PARAM_DATA);
    73		dev_dbg(dfluart->dev, "UART_FIFO_ID fifo_len %llu\n", dfluart->fifo_len);
    74	
    75		off = dfl_find_param(param_base, max, DFHv1_PARAM_ID_REG_LAYOUT);
    76		if (off < 0) {
    77			dev_err(dfluart->dev, "missing REG_LAYOUT param\n");
    78			return -EINVAL;
    79		}
    80	
    81		v = readq(param_base + off + DFHv1_PARAM_DATA);
    82		dfluart->fifo_size = FIELD_GET(DFHv1_PARAM_ID_REG_WIDTH, v);
    83		dfluart->reg_shift = FIELD_GET(DFHv1_PARAM_ID_REG_SHIFT, v);
    84		dev_dbg(dfluart->dev, "UART_LAYOUT_ID width %d shift %d\n",
    85			dfluart->fifo_size, dfluart->reg_shift);
    86	
    87		return 0;
    88	}
    89	

-- 
0-DAY CI Kernel Test Service
https://01.org/lkp