Hi Melissa, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Melissa-Wen/drm-amd-display-restore-edid-reading-from-a-given-i2c-adapter/20250210-070016 base: https://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos.git exynos-drm-next patch link: https://lore.kernel.org/r/20250209225843.7412-1-mwen%40igalia.com patch subject: [PATCH] drm/amd/display: restore edid reading from a given i2c adapter config: x86_64-randconfig-161-20250211 (https://download.01.org/0day-ci/archive/20250212/202502121000.EBCEdoo9-lkp@xxxxxxxxx/config) compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202502121000.EBCEdoo9-lkp@xxxxxxxxx/ New smatch warnings: drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:7201 amdgpu_dm_connector_funcs_force() warn: variable dereferenced before check 'dc_link' (see line 7187) Old smatch warnings: drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:12110 parse_edid_displayid_vrr() warn: variable dereferenced before check 'edid_ext' (see line 12106) vim +/dc_link +7201 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c dae343b343ff741 Arnd Bergmann 2023-05-01 7179 static void amdgpu_dm_connector_funcs_force(struct drm_connector *connector) 0ba4a784a14592a Alex Hung 2023-04-05 7180 { 0ba4a784a14592a Alex Hung 2023-04-05 7181 struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector); 0ba4a784a14592a Alex Hung 2023-04-05 7182 struct dc_link *dc_link = aconnector->dc_link; 0ba4a784a14592a Alex Hung 2023-04-05 7183 struct dc_sink *dc_em_sink = aconnector->dc_em_sink; 48edb2a4256eedf Melissa Wen 2024-09-27 7184 const struct drm_edid *drm_edid; be1aae525741575 Melissa Wen 2025-02-09 7185 struct i2c_adapter *ddc; 0ba4a784a14592a Alex Hung 2023-04-05 7186 be1aae525741575 Melissa Wen 2025-02-09 @7187 if (dc_link->aux_mode) ^^^^^^^^^^^^^^^^^ Unchecked dereference be1aae525741575 Melissa Wen 2025-02-09 7188 ddc = &aconnector->dm_dp_aux.aux.ddc; be1aae525741575 Melissa Wen 2025-02-09 7189 else be1aae525741575 Melissa Wen 2025-02-09 7190 ddc = &aconnector->i2c->base; be1aae525741575 Melissa Wen 2025-02-09 7191 be1aae525741575 Melissa Wen 2025-02-09 7192 drm_edid = drm_edid_read_ddc(connector, ddc); 48edb2a4256eedf Melissa Wen 2024-09-27 7193 drm_edid_connector_update(connector, drm_edid); 48edb2a4256eedf Melissa Wen 2024-09-27 7194 if (!drm_edid) { 0e859faf8670a78 Alex Hung 2023-08-25 7195 DRM_ERROR("No EDID found on connector: %s.\n", connector->name); 0ba4a784a14592a Alex Hung 2023-04-05 7196 return; 0e859faf8670a78 Alex Hung 2023-08-25 7197 } 0ba4a784a14592a Alex Hung 2023-04-05 7198 48edb2a4256eedf Melissa Wen 2024-09-27 7199 aconnector->drm_edid = drm_edid; 0ba4a784a14592a Alex Hung 2023-04-05 7200 /* Update emulated (virtual) sink's EDID */ 0ba4a784a14592a Alex Hung 2023-04-05 @7201 if (dc_em_sink && dc_link) { ^^^^^^^ This code assumes dc_link can be NULL 48edb2a4256eedf Melissa Wen 2024-09-27 7202 // FIXME: Get rid of drm_edid_raw() 48edb2a4256eedf Melissa Wen 2024-09-27 7203 const struct edid *edid = drm_edid_raw(drm_edid); 48edb2a4256eedf Melissa Wen 2024-09-27 7204 0ba4a784a14592a Alex Hung 2023-04-05 7205 memset(&dc_em_sink->edid_caps, 0, sizeof(struct dc_edid_caps)); 48edb2a4256eedf Melissa Wen 2024-09-27 7206 memmove(dc_em_sink->dc_edid.raw_edid, edid, 48edb2a4256eedf Melissa Wen 2024-09-27 7207 (edid->extensions + 1) * EDID_LENGTH); 0ba4a784a14592a Alex Hung 2023-04-05 7208 dm_helpers_parse_edid_caps( 0ba4a784a14592a Alex Hung 2023-04-05 7209 dc_link, 0ba4a784a14592a Alex Hung 2023-04-05 7210 &dc_em_sink->dc_edid, 0ba4a784a14592a Alex Hung 2023-04-05 7211 &dc_em_sink->edid_caps); 0ba4a784a14592a Alex Hung 2023-04-05 7212 } 0ba4a784a14592a Alex Hung 2023-04-05 7213 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
