Hi Sergey, I love your patch! Perhaps something to improve: [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Sergey-Ryazanov/WWAN-debugfs-tweaks/20211128-210031 base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git d40ce48cb3a68b54be123a1f99157c5ac613e260 config: i386-randconfig-a001-20211128 (https://download.01.org/0day-ci/archive/20211129/202111290026.HEuigppG-lkp@intel.com/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 5c64d8ef8cc0c0ed3e0f2ae693d99e7f70f20a84) 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/89654e5e973a53b8375f37395c03359c59b63a99 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Sergey-Ryazanov/WWAN-debugfs-tweaks/20211128-210031 git checkout 89654e5e973a53b8375f37395c03359c59b63a99 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/net/wwan/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> drivers/net/wwan/wwan_core.c:171:14: warning: variable 'wwandev_name' set but not used [-Wunused-but-set-variable] const char *wwandev_name; ^ 1 warning generated. vim +/wwandev_name +171 drivers/net/wwan/wwan_core.c c4804670026b93f M Chetan Kumar 2021-11-20 162 9a44c1cc6388762 Loic Poulain 2021-04-16 163 /* This function allocates and registers a new WWAN device OR if a WWAN device 9a44c1cc6388762 Loic Poulain 2021-04-16 164 * already exist for the given parent, it gets a reference and return it. 9a44c1cc6388762 Loic Poulain 2021-04-16 165 * This function is not exported (for now), it is called indirectly via 9a44c1cc6388762 Loic Poulain 2021-04-16 166 * wwan_create_port(). 9a44c1cc6388762 Loic Poulain 2021-04-16 167 */ 9a44c1cc6388762 Loic Poulain 2021-04-16 168 static struct wwan_device *wwan_create_dev(struct device *parent) 9a44c1cc6388762 Loic Poulain 2021-04-16 169 { 9a44c1cc6388762 Loic Poulain 2021-04-16 170 struct wwan_device *wwandev; c4804670026b93f M Chetan Kumar 2021-11-20 @171 const char *wwandev_name; 9a44c1cc6388762 Loic Poulain 2021-04-16 172 int err, id; 9a44c1cc6388762 Loic Poulain 2021-04-16 173 9a44c1cc6388762 Loic Poulain 2021-04-16 174 /* The 'find-alloc-register' operation must be protected against 9a44c1cc6388762 Loic Poulain 2021-04-16 175 * concurrent execution, a WWAN device is possibly shared between 9a44c1cc6388762 Loic Poulain 2021-04-16 176 * multiple callers or concurrently unregistered from wwan_remove_dev(). 9a44c1cc6388762 Loic Poulain 2021-04-16 177 */ 9a44c1cc6388762 Loic Poulain 2021-04-16 178 mutex_lock(&wwan_register_lock); 9a44c1cc6388762 Loic Poulain 2021-04-16 179 9a44c1cc6388762 Loic Poulain 2021-04-16 180 /* If wwandev already exists, return it */ 9a44c1cc6388762 Loic Poulain 2021-04-16 181 wwandev = wwan_dev_get_by_parent(parent); 9a44c1cc6388762 Loic Poulain 2021-04-16 182 if (!IS_ERR(wwandev)) 9a44c1cc6388762 Loic Poulain 2021-04-16 183 goto done_unlock; 9a44c1cc6388762 Loic Poulain 2021-04-16 184 9a44c1cc6388762 Loic Poulain 2021-04-16 185 id = ida_alloc(&wwan_dev_ids, GFP_KERNEL); d9d5b8961284b00 Andy Shevchenko 2021-08-11 186 if (id < 0) { d9d5b8961284b00 Andy Shevchenko 2021-08-11 187 wwandev = ERR_PTR(id); 9a44c1cc6388762 Loic Poulain 2021-04-16 188 goto done_unlock; d9d5b8961284b00 Andy Shevchenko 2021-08-11 189 } 9a44c1cc6388762 Loic Poulain 2021-04-16 190 9a44c1cc6388762 Loic Poulain 2021-04-16 191 wwandev = kzalloc(sizeof(*wwandev), GFP_KERNEL); 9a44c1cc6388762 Loic Poulain 2021-04-16 192 if (!wwandev) { d9d5b8961284b00 Andy Shevchenko 2021-08-11 193 wwandev = ERR_PTR(-ENOMEM); 9a44c1cc6388762 Loic Poulain 2021-04-16 194 ida_free(&wwan_dev_ids, id); 9a44c1cc6388762 Loic Poulain 2021-04-16 195 goto done_unlock; 9a44c1cc6388762 Loic Poulain 2021-04-16 196 } 9a44c1cc6388762 Loic Poulain 2021-04-16 197 9a44c1cc6388762 Loic Poulain 2021-04-16 198 wwandev->dev.parent = parent; 9a44c1cc6388762 Loic Poulain 2021-04-16 199 wwandev->dev.class = wwan_class; 9a44c1cc6388762 Loic Poulain 2021-04-16 200 wwandev->dev.type = &wwan_dev_type; 9a44c1cc6388762 Loic Poulain 2021-04-16 201 wwandev->id = id; 9a44c1cc6388762 Loic Poulain 2021-04-16 202 dev_set_name(&wwandev->dev, "wwan%d", wwandev->id); 9a44c1cc6388762 Loic Poulain 2021-04-16 203 9a44c1cc6388762 Loic Poulain 2021-04-16 204 err = device_register(&wwandev->dev); 9a44c1cc6388762 Loic Poulain 2021-04-16 205 if (err) { 9a44c1cc6388762 Loic Poulain 2021-04-16 206 put_device(&wwandev->dev); d9d5b8961284b00 Andy Shevchenko 2021-08-11 207 wwandev = ERR_PTR(err); d9d5b8961284b00 Andy Shevchenko 2021-08-11 208 goto done_unlock; 9a44c1cc6388762 Loic Poulain 2021-04-16 209 } 9a44c1cc6388762 Loic Poulain 2021-04-16 210 c4804670026b93f M Chetan Kumar 2021-11-20 211 wwandev_name = kobject_name(&wwandev->dev.kobj); 89654e5e973a53b Sergey Ryazanov 2021-11-28 212 #ifdef CONFIG_WWAN_DEBUGFS c4804670026b93f M Chetan Kumar 2021-11-20 213 wwandev->debugfs_dir = debugfs_create_dir(wwandev_name, c4804670026b93f M Chetan Kumar 2021-11-20 214 wwan_debugfs_dir); 89654e5e973a53b Sergey Ryazanov 2021-11-28 215 #endif c4804670026b93f M Chetan Kumar 2021-11-20 216 9a44c1cc6388762 Loic Poulain 2021-04-16 217 done_unlock: 9a44c1cc6388762 Loic Poulain 2021-04-16 218 mutex_unlock(&wwan_register_lock); 9a44c1cc6388762 Loic Poulain 2021-04-16 219 9a44c1cc6388762 Loic Poulain 2021-04-16 220 return wwandev; 9a44c1cc6388762 Loic Poulain 2021-04-16 221 } 9a44c1cc6388762 Loic Poulain 2021-04-16 222 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org