Hi Ryder, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: b791d1bdf9212d944d749a5c7ff6febdba241771 commit: ec9742a8f38ef69876e9f04be68d985c6bbb8f5f mt76: mt7915: add .sta_add_debugfs support date: 4 weeks ago config: microblaze-randconfig-r023-20200612 (attached as .config) compiler: microblaze-linux-gcc (GCC) 9.3.0 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 git checkout ec9742a8f38ef69876e9f04be68d985c6bbb8f5f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): >> drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c:365:6: warning: no previous prototype for 'mt7915_sta_add_debugfs' [-Wmissing-prototypes] 365 | void mt7915_sta_add_debugfs(struct ieee80211_hw *hw, struct ieee80211_vif *vif, | ^~~~~~~~~~~~~~~~~~~~~~ vim +/mt7915_sta_add_debugfs +365 drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c 364 > 365 void mt7915_sta_add_debugfs(struct ieee80211_hw *hw, struct ieee80211_vif *vif, --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org