Hi Ryder, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 11ba468877bb23f28956a35e896356252d63c983 commit: ec9742a8f38ef69876e9f04be68d985c6bbb8f5f mt76: mt7915: add .sta_add_debugfs support date: 9 weeks ago config: i386-randconfig-r025-20200713 (attached as .config) compiler: gcc-9 (Debian 9.3.0-14) 9.3.0 reproduce (this is a W=1 build): git checkout ec9742a8f38ef69876e9f04be68d985c6bbb8f5f # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new 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