Re: [PATCH v7 2/4] drm/loongson: Add GPIO and I2C driver for loongson drm.

[kernel test robot <lkp@intel.com>]

Hi Chenyang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm/drm-next]
[also build test WARNING on v5.18-rc3 next-20220422]
[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/intel-lab-lkp/linux/commits/Chenyang-Li/drm-loongson-Add-DRM-Driver-for-Loongson-7A1000-bridge-chip/20220422-161914
base:   git://anongit.freedesktop.org/drm/drm drm-next
config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20220423/202204230046.2fBNTJrK-lkp@intel.com/config)
compiler: riscv64-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/intel-lab-lkp/linux/commit/4a5b6ac99c37617e030a054ca431c5c9aab227b8
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Chenyang-Li/drm-loongson-Add-DRM-Driver-for-Loongson-7A1000-bridge-chip/20220422-161914
        git checkout 4a5b6ac99c37617e030a054ca431c5c9aab227b8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/gpu/drm/loongson/

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

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/loongson/loongson_encoder.c:10:27: warning: no previous prototype for 'loongson_bridge_detect' [-Wmissing-prototypes]
      10 | enum drm_connector_status loongson_bridge_detect(struct drm_bridge *bridge)
         |                           ^~~~~~~~~~~~~~~~~~~~~~


vim +/loongson_bridge_detect +10 drivers/gpu/drm/loongson/loongson_encoder.c

     9	
  > 10	enum drm_connector_status loongson_bridge_detect(struct drm_bridge *bridge)
    11	{
    12		unsigned char start = 0x0;
    13		struct i2c_msg msgs = {
    14			.addr = DDC_ADDR,
    15			.flags = 0,
    16			.len = 1,
    17			.buf = &start,
    18		};
    19	
    20		if (i2c_transfer(bridge->ddc, &msgs, 1) != 1)
    21			return connector_status_disconnected;
    22		else
    23			return connector_status_connected;
    24	}
    25	

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