tree: https://github.com/0day-ci/linux/commits/UPDATE-20210916-220656/Lee-Shawn-C/drm-i915-dsi-unregister-gmbus-if-LFP-display-was-MIPI-panel/20210916-181936 head: 37a6b71c76cc745b62b40e77e7f882ff7ceeadb0 commit: 37a6b71c76cc745b62b40e77e7f882ff7ceeadb0 drm/i915/dsi: do not register gmbus if it was reserved for MIPI display date: 9 hours ago config: i386-randconfig-a002-20210916 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c8b3d7d6d6de37af68b2f379d0e37304f78e115f) 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 # https://github.com/0day-ci/linux/commit/37a6b71c76cc745b62b40e77e7f882ff7ceeadb0 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review UPDATE-20210916-220656/Lee-Shawn-C/drm-i915-dsi-unregister-gmbus-if-LFP-display-was-MIPI-panel/20210916-181936 git checkout 37a6b71c76cc745b62b40e77e7f882ff7ceeadb0 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 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/gpu/drm/i915/display/intel_gmbus.c:144:6: warning: no previous prototype for function 'intel_gmbus_ddc_reserve_for_mipi' [-Wmissing-prototypes] bool intel_gmbus_ddc_reserve_for_mipi(struct drm_i915_private *dev_priv, ^ drivers/gpu/drm/i915/display/intel_gmbus.c:144:1: note: declare 'static' if the function is not intended to be used outside of this translation unit bool intel_gmbus_ddc_reserve_for_mipi(struct drm_i915_private *dev_priv, ^ static 1 warning generated. vim +/intel_gmbus_ddc_reserve_for_mipi +144 drivers/gpu/drm/i915/display/intel_gmbus.c 143 > 144 bool intel_gmbus_ddc_reserve_for_mipi(struct drm_i915_private *dev_priv, 145 unsigned int pin) 146 { 147 enum port port; 148 149 if (intel_bios_is_dsi_present(dev_priv, &port)) { 150 if (DISPLAY_VER(dev_priv) >= 11) { 151 if ((pin == GMBUS_PIN_2_BXT && dev_priv->vbt.dsi.config->dual_link) || 152 pin == GMBUS_PIN_1_BXT) 153 return true; 154 } 155 } 156 157 return false; 158 } 159 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org