tree:   https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-5.10
head:   a7bda7faa61f2db4f9621b6f74c3bfae5116f7e8
commit: 6dc1da9d1b725e1e10913542997534d8c560e280 [14052/15491] UPSTREAM: drm/amd/display: add exit training mode and update channel coding in LT
config: arm-randconfig-r023-20210702 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9eb613b2de3163686b1a4bd1160f15ac56a4b083)
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
        # install arm cross compiling tool for clang build
        # apt-get install binutils-arm-linux-gnueabi
        git remote add chrome-os https://chromium.googlesource.com/chromiumos/third_party/kernel
        git fetch --no-tags chrome-os chromeos-5.10
        git checkout 6dc1da9d1b725e1e10913542997534d8c560e280
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm 

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 >>):

   drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1370:16: error: no previous prototype for function 'configure_lttpr_mode_transparent' [-Werror,-Wmissing-prototypes]
   enum dc_status configure_lttpr_mode_transparent(struct dc_link *link)
                  ^
   drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1370:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   enum dc_status configure_lttpr_mode_transparent(struct dc_link *link)
   ^
   static 
   drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1381:16: error: no previous prototype for function 'configure_lttpr_mode_non_transparent' [-Werror,-Wmissing-prototypes]
   enum dc_status configure_lttpr_mode_non_transparent(
                  ^
   drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1381:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   enum dc_status configure_lttpr_mode_non_transparent(
   ^
   static 
>> drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1638:16: error: no previous prototype for function 'dpcd_configure_channel_coding' [-Werror,-Wmissing-prototypes]
   enum dc_status dpcd_configure_channel_coding(struct dc_link *link,
                  ^
   drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c:1638:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   enum dc_status dpcd_configure_channel_coding(struct dc_link *link,
   ^
   static 
   3 errors generated.


vim +/dpcd_configure_channel_coding +1638 drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link_dp.c

  1637	
> 1638	enum dc_status dpcd_configure_channel_coding(struct dc_link *link,
  1639			struct link_training_settings *lt_settings)
  1640	{
  1641		enum dp_link_encoding encoding =
  1642				dp_get_link_encoding_format(
  1643						&lt_settings->link_settings);
  1644		enum dc_status status;
  1645	
  1646		status = core_link_write_dpcd(
  1647				link,
  1648				DP_MAIN_LINK_CHANNEL_CODING_SET,
  1649				(uint8_t *) &encoding,
  1650				1);
  1651		DC_LOG_HW_LINK_TRAINING("%s:\n 0x%X MAIN_LINK_CHANNEL_CODING_SET = %x\n",
  1652						__func__,
  1653						DP_MAIN_LINK_CHANNEL_CODING_SET,
  1654						encoding);
  1655	
  1656		return status;
  1657	}
  1658	

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