tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: fb3b0673b7d5b477ed104949450cd511337ba3c6 commit: 55dc449a7c60d3df5a8f0b71bbae9d5173c864f5 drm/ast: Handle failed I2C initialization gracefully date: 4 weeks ago config: riscv-randconfig-c006-20220113 (https://download.01.org/0day-ci/archive/20220114/202201141416.VfNXpsi5-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d1021978b8e7e35dcc30201ca1731d64b5a602a8) 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 # install riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 55dc449a7c60d3df5a8f0b71bbae9d5173c864f5 # save the config file to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; clang-analyzer warnings: (new ones prefixed by >>) drm_connector_update_edid_property(&ast_connector->base, edid); ^ ~~~~ drivers/gpu/drm/ast/ast_mode.c:1217:6: note: Assuming field 'tx_chip_type' is equal to AST_TX_DP501 if (ast->tx_chip_type == AST_TX_DP501) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/gpu/drm/ast/ast_mode.c:1217:2: note: Taking true branch if (ast->tx_chip_type == AST_TX_DP501) { ^ drivers/gpu/drm/ast/ast_mode.c:1220:7: note: Assuming 'edid' is non-null if (!edid) ^~~~~ drivers/gpu/drm/ast/ast_mode.c:1220:3: note: Taking false branch if (!edid) ^ drivers/gpu/drm/ast/ast_mode.c:1224:7: note: Assuming 'flags' is false if (flags) ^~~~~ drivers/gpu/drm/ast/ast_mode.c:1224:3: note: Taking false branch if (flags) ^ drivers/gpu/drm/ast/ast_mode.c:1227:4: note: Memory is released kfree(edid); ^~~~~~~~~~~ drivers/gpu/drm/ast/ast_mode.c:1229:7: note: 'flags' is false if (!flags && ast_connector->i2c) ^~~~~ drivers/gpu/drm/ast/ast_mode.c:1229:6: note: Left side of '&&' is true if (!flags && ast_connector->i2c) ^ drivers/gpu/drm/ast/ast_mode.c:1229:16: note: Assuming field 'i2c' is null if (!flags && ast_connector->i2c) ^~~~~~~~~~~~~~~~~~ drivers/gpu/drm/ast/ast_mode.c:1229:2: note: Taking false branch if (!flags && ast_connector->i2c) ^ drivers/gpu/drm/ast/ast_mode.c:1231:6: note: 'edid' is non-null if (edid) { ^~~~ drivers/gpu/drm/ast/ast_mode.c:1231:2: note: Taking true branch if (edid) { ^ drivers/gpu/drm/ast/ast_mode.c:1232:3: note: Use of memory after it is freed drm_connector_update_edid_property(&ast_connector->base, edid); ^ ~~~~ vim +1232 drivers/gpu/drm/ast/ast_mode.c 312fec1405dd54 Dave Airlie 2012-02-29 1204 4961eb60f14553 Thomas Zimmermann 2019-11-07 1205 /* 4961eb60f14553 Thomas Zimmermann 2019-11-07 1206 * Connector 4961eb60f14553 Thomas Zimmermann 2019-11-07 1207 */ 4961eb60f14553 Thomas Zimmermann 2019-11-07 1208 312fec1405dd54 Dave Airlie 2012-02-29 1209 static int ast_get_modes(struct drm_connector *connector) 312fec1405dd54 Dave Airlie 2012-02-29 1210 { 312fec1405dd54 Dave Airlie 2012-02-29 1211 struct ast_connector *ast_connector = to_ast_connector(connector); fa7dbd7688849d Thomas Zimmermann 2020-06-17 1212 struct ast_private *ast = to_ast_private(connector->dev); 55dc449a7c60d3 Thomas Zimmermann 2021-12-06 1213 struct edid *edid = NULL; 83c6620bae3f14 Dave Airlie 2014-03-28 1214 bool flags = false; 55dc449a7c60d3 Thomas Zimmermann 2021-12-06 1215 int ret; 6c9bd4432b2527 Gregory Williams 2021-07-30 1216 83c6620bae3f14 Dave Airlie 2014-03-28 1217 if (ast->tx_chip_type == AST_TX_DP501) { 83c6620bae3f14 Dave Airlie 2014-03-28 1218 ast->dp501_maxclk = 0xff; 83c6620bae3f14 Dave Airlie 2014-03-28 1219 edid = kmalloc(128, GFP_KERNEL); 83c6620bae3f14 Dave Airlie 2014-03-28 1220 if (!edid) 83c6620bae3f14 Dave Airlie 2014-03-28 1221 return -ENOMEM; 312fec1405dd54 Dave Airlie 2012-02-29 1222 83c6620bae3f14 Dave Airlie 2014-03-28 1223 flags = ast_dp501_read_edid(connector->dev, (u8 *)edid); 83c6620bae3f14 Dave Airlie 2014-03-28 1224 if (flags) 83c6620bae3f14 Dave Airlie 2014-03-28 1225 ast->dp501_maxclk = ast_get_dp501_max_clk(connector->dev); 83c6620bae3f14 Dave Airlie 2014-03-28 1226 else 83c6620bae3f14 Dave Airlie 2014-03-28 1227 kfree(edid); 83c6620bae3f14 Dave Airlie 2014-03-28 1228 } 55dc449a7c60d3 Thomas Zimmermann 2021-12-06 1229 if (!flags && ast_connector->i2c) 312fec1405dd54 Dave Airlie 2012-02-29 1230 edid = drm_get_edid(connector, &ast_connector->i2c->adapter); 312fec1405dd54 Dave Airlie 2012-02-29 1231 if (edid) { c555f02371c338 Daniel Vetter 2018-07-09 @1232 drm_connector_update_edid_property(&ast_connector->base, edid); 312fec1405dd54 Dave Airlie 2012-02-29 1233 ret = drm_add_edid_modes(connector, edid); 993dcb05e47e35 Jani Nikula 2012-08-15 1234 kfree(edid); 312fec1405dd54 Dave Airlie 2012-02-29 1235 return ret; 6c9bd4432b2527 Gregory Williams 2021-07-30 1236 } c555f02371c338 Daniel Vetter 2018-07-09 1237 drm_connector_update_edid_property(&ast_connector->base, NULL); 312fec1405dd54 Dave Airlie 2012-02-29 1238 return 0; 312fec1405dd54 Dave Airlie 2012-02-29 1239 } 312fec1405dd54 Dave Airlie 2012-02-29 1240 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org