[ammarfaizi2-block:next/linux-next/master 97/182] drivers/gpu/drm/dp/drm_dp.c:210:4: warning: no previous prototype for 'drm_dp_get_adjust_request_post_cursor'

[ammarfaizi2-block:next/linux-next/master 97/182] drivers/gpu/drm/dp/drm_dp.c:210:4: warning: no previous prototype for 'drm_dp_get_adjust_request_post_cursor'

[kernel test robot]

tree:   https://github.com/ammarfaizi2/linux-block next/linux-next/master
head:   196d330d7fb1e7cc0d85641c89ce4602cb36f12e
commit: b885fbed0eb9d79d96a1f8145dc430e14fb33808 [97/182] Merge branch 'for-linux-next' of git://anongit.freedesktop.org/drm-intel
config: i386-randconfig-s002-20220221 (https://download.01.org/0day-ci/archive/20220223/202202231535.7QHMYyoH-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/ammarfaizi2/linux-block/commit/b885fbed0eb9d79d96a1f8145dc430e14fb33808
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block next/linux-next/master
        git checkout b885fbed0eb9d79d96a1f8145dc430e14fb33808
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash

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/dp/drm_dp.c:210:4: warning: no previous prototype for 'drm_dp_get_adjust_request_post_cursor' [-Wmissing-prototypes]
     210 | u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
         |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/drm_dp_get_adjust_request_post_cursor +210 drivers/gpu/drm/dp/drm_dp.c

0192c25c03cd2f drivers/gpu/drm/drm_dp_helper.c Jani Nikula    2022-02-03  209  
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21 @210  u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  211  					 unsigned int lane)
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  212  {
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  213  	unsigned int offset = DP_ADJUST_REQUEST_POST_CURSOR2;
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  214  	u8 value = dp_link_status(link_status, offset);
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  215  
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  216  	return (value >> (lane << 1)) & 0x3;
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  217  }
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  218  EXPORT_SYMBOL(drm_dp_get_adjust_request_post_cursor);
79465e0ffeb9e4 drivers/gpu/drm/drm_dp_helper.c Thierry Reding 2019-10-21  219  

:::::: The code at line 210 was first introduced by commit
:::::: 79465e0ffeb9e4866939ea562bc55367be91e595 drm/dp: Add helper to get post-cursor adjustments

:::::: TO: Thierry Reding <treding@nvidia.com>
:::::: CC: Thierry Reding <treding@nvidia.com>

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