tree: https://chromium.googlesource.com/chromiumos/third_party/kernel chromeos-5.4 head: 15d194a5987968744e349126609033f418625127 commit: 09cbe8d3853433d8c98826761d0a2c68013e7250 [59/70] CHROMIUM: drm/dp: Add DisplayPort aux backlight control support config: x86_64-randconfig-m001-20210516 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; Reported-by: Dan Carpenter <dan.carpenter(a)oracle.com&gt; smatch warnings: drivers/gpu/drm/drm_dp_aux_backlight.c:177 drm_dp_aux_backlight_register() warn: passing zero to 'PTR_ERR' vim +/PTR_ERR +177 drivers/gpu/drm/drm_dp_aux_backlight.c 09cbe8d3853433 Rajeev Nandan 2021-04-07 158 int drm_dp_aux_backlight_register(const char *name, 09cbe8d3853433 Rajeev Nandan 2021-04-07 159 struct drm_dp_aux_backlight *aux_bl) 09cbe8d3853433 Rajeev Nandan 2021-04-07 160 { 09cbe8d3853433 Rajeev Nandan 2021-04-07 161 struct backlight_properties bl_props = { 0 }; 09cbe8d3853433 Rajeev Nandan 2021-04-07 162 int max_brightness; 09cbe8d3853433 Rajeev Nandan 2021-04-07 163 09cbe8d3853433 Rajeev Nandan 2021-04-07 164 if (!name || !aux_bl || !aux_bl->aux) 09cbe8d3853433 Rajeev Nandan 2021-04-07 165 return -EINVAL; 09cbe8d3853433 Rajeev Nandan 2021-04-07 166 09cbe8d3853433 Rajeev Nandan 2021-04-07 167 max_brightness = 0xffff; 09cbe8d3853433 Rajeev Nandan 2021-04-07 168 09cbe8d3853433 Rajeev Nandan 2021-04-07 169 bl_props.type = BACKLIGHT_RAW; 09cbe8d3853433 Rajeev Nandan 2021-04-07 170 bl_props.brightness = max_brightness; 09cbe8d3853433 Rajeev Nandan 2021-04-07 171 bl_props.max_brightness = max_brightness; 09cbe8d3853433 Rajeev Nandan 2021-04-07 172 aux_bl->bd = devm_backlight_device_register(aux_bl->dev, name, 09cbe8d3853433 Rajeev Nandan 2021-04-07 173 aux_bl->dev, aux_bl, 09cbe8d3853433 Rajeev Nandan 2021-04-07 174 &aux_bl_ops, &bl_props); 09cbe8d3853433 Rajeev Nandan 2021-04-07 175 if (IS_ERR(aux_bl->bd)) { 09cbe8d3853433 Rajeev Nandan 2021-04-07 176 aux_bl->bd = NULL; ^^^^^^^^^^^^^^^^^^ Preserve the error code before setting this to NULL 09cbe8d3853433 Rajeev Nandan 2021-04-07 @177 return PTR_ERR(aux_bl->bd); ^^^^^^^^^^^^^^^^^^^^^^^^^^ PTR_ERR(NULL) is success. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org