Hi "Jonathan, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on lee-mfd/for-mfd-next] [also build test WARNING on robh/for-next pwm/for-next abelloni/rtc-next linus/master v5.11-rc3 next-20210115] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Jonathan-Neusch-fer/Netronix-emb... base: https://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd.git for-mfd-next config: mips-randconfig-r001-20210117 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 2082b10d100e8dbaffc2ba8f497db5d2ab61beb2) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://github.com/0day-ci/linux/commit/eee80e6b3b7cc2c733bd3f10d8e2ec23d... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jonathan-Neusch-fer/Netronix-embedded-controller-driver-for-Kobo-and-Tolino-ebook-readers/20210117-050203 git checkout eee80e6b3b7cc2c733bd3f10d8e2ec23dda2fe26 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): return res; ^~~ drivers/mfd/ntxec.c:116:9: note: initialize the variable 'res' to silence this warning int res; ^ = 0 1 warning generated. vim +/res +127 drivers/mfd/ntxec.c 111 112 static int ntxec_probe(struct i2c_client *client) 113 { 114 struct ntxec *ec; 115 unsigned int version; 116 int res; 117 118 ec = devm_kmalloc(&client->dev, sizeof(*ec), GFP_KERNEL); 119 if (!ec) 120 return -ENOMEM; 121 122 ec->dev = &client->dev; 123 124 ec->regmap = devm_regmap_init_i2c(client, &regmap_config); 125 if (IS_ERR(ec->regmap)) { 126 dev_err(ec->dev, "Failed to set up regmap for device\n"); 128 } 129 130 /* Determine the firmware version */ 131 res = regmap_read(ec->regmap, NTXEC_REG_VERSION, &version); 132 if (res < 0) { 133 dev_err(ec->dev, "Failed to read firmware version number\n"); 134 return res; 135 } 136 137 /* Bail out if we encounter an unknown firmware version */ 138 switch (version) { 139 case NTXEC_VERSION_KOBO_AURA: 140 break; 141 default: 142 dev_err(ec->dev, 143 "Netronix embedded controller version %04x is not supported.\n", 144 version); 145 return -ENODEV; 146 } 147 148 dev_info(ec->dev, 149 "Netronix embedded controller version %04x detected.\n", version); 150 151 if (of_device_is_system_power_controller(ec->dev->of_node)) { 152 /* 153 * Set the 'powerkeep' bit. This is necessary on some boards 154 * in order to keep the system running. 155 */ 156 res = regmap_write(ec->regmap, NTXEC_REG_POWERKEEP, 157 NTXEC_POWERKEEP_VALUE); 158 if (res < 0) 159 return res; 160 161 if (poweroff_restart_client) 162 /* 163 * Another instance of the driver already took 164 * poweroff/restart duties. 165 */ 166 dev_err(ec->dev, "poweroff_restart_client already assigned\n"); 167 else 168 poweroff_restart_client = client; 169 170 if (pm_power_off) 171 /* Another driver already registered a poweroff handler. */ 172 dev_err(ec->dev, "pm_power_off already assigned\n"); 173 else 174 pm_power_off = ntxec_poweroff; 175 176 res = register_restart_handler(&ntxec_restart_handler); 177 if (res) 178 dev_err(ec->dev, 179 "Failed to register restart handler: %d\n", res); 180 } 181 182 i2c_set_clientdata(client, ec); 183 184 res = devm_mfd_add_devices(ec->dev, PLATFORM_DEVID_NONE, ntxec_subdevices, 185 ARRAY_SIZE(ntxec_subdevices), NULL, 0, NULL); 186 if (res) 187 dev_err(ec->dev, "Failed to add subdevices: %d\n", res); 188 189 return res; 190 } 191 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org