tree: git://git.kernel.org/pub/scm/linux/kernel/git/lkundrak/linux-mmp.git lr/ariel head: 551dcc39c19e9fe56fe48a92ae52f31367ed8dd0 commit: 3e76766cc78ce69dce80dba27d3aca54e68bdf45 [5/41] Merge remote-tracking branch 'xo/lr/olpc-xo175-fixes5-drm' into merged config: arc-allyesconfig (attached as .config) compiler: arc-elf-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 3e76766cc78ce69dce80dba27d3aca54e68bdf45 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Note: the lkundrak-linux-mmp/lr/ariel HEAD 551dcc39c19e9fe56fe48a92ae52f31367ed8dd0 builds fine. It only hurts bisectibility. All error/warnings (new ones prefixed by >>, old ones prefixed by <<): drivers/gpu/drm/i2c/hx8837.c: In function 'hx8837_connector_get_modes': 471 | return priv->panel->funcs->get_modes(priv->panel); | ^~~~ 472 | } | ^ At top level: drivers/gpu/drm/i2c/hx8837.c:739:12: warning: 'hx8837_resume' defined but not used [-Wunused-function] 739 | static int hx8837_resume(struct device *dev) | ^~~~~~~~~~~~~ drivers/gpu/drm/i2c/hx8837.c:729:12: warning: 'hx8837_suspend' defined but not used [-Wunused-function] 729 | static int hx8837_suspend(struct device *dev) | ^~~~~~~~~~~~~~ vim +471 drivers/gpu/drm/i2c/hx8837.c 7343a41fc803d40 Lubomir Rintel 2018-09-11 466 7343a41fc803d40 Lubomir Rintel 2018-09-11 467 static int hx8837_connector_get_modes(struct drm_connector *connector) 7343a41fc803d40 Lubomir Rintel 2018-09-11 468 { 7343a41fc803d40 Lubomir Rintel 2018-09-11 469 struct hx8837_priv *priv = container_of(connector, struct hx8837_priv, connector); 7343a41fc803d40 Lubomir Rintel 2018-09-11 470 7343a41fc803d40 Lubomir Rintel 2018-09-11 @471 return priv->panel->funcs->get_modes(priv->panel); 7343a41fc803d40 Lubomir Rintel 2018-09-11 @472 } 7343a41fc803d40 Lubomir Rintel 2018-09-11 473 :::::: The code at line 471 was first introduced by commit :::::: 7343a41fc803d403df5baf0743061bed74efedc8 drm/i2c: hx8837: add a Himax HX8837 display controller driver :::::: TO: Lubomir Rintel <lkundrak(a)v3.sk&gt; :::::: CC: Lubomir Rintel <lkundrak(a)v3.sk&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org