Hi Ng, FYI, the error/warning still remains. tree: https://github.com/intel/linux-intel-lts.git 5.10/yocto head: 2dafc777a64181d42982628c7f5907a03da5f070 commit: bd8c7120c481ebe8e2e40e6b9308d689f8adfff7 [10648/20393] media: ti960: remove crlmodule dependency config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220211/202202110149.oMw9L4SG-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/intel/linux-intel-lts/commit/bd8c7120c481ebe8e2e40e6b9... git remote add intel-lts https://github.com/intel/linux-intel-lts.git git fetch --no-tags intel-lts 5.10/yocto git checkout bd8c7120c481ebe8e2e40e6b9308d689f8adfff7 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash arch/x86/crypto/ drivers/gpio/ drivers/gpu/drm/i915/ drivers/media/i2c/ 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 >>): 129 | int bus_switch(struct ti960 *va) | ^~~~~~~~~~ drivers/media/i2c/ti960-des.c: In function 'ti960_init': drivers/media/i2c/ti960-des.c:1240:15: warning: unused variable 'reset_gpio' [-Wunused-variable] 1240 | unsigned int reset_gpio = va->pdata->reset_gpio; | ^~~~~~~~~~ In file included from drivers/media/i2c/ti960-des.c:20: At top level: drivers/media/i2c/ti953.h:101:42: warning: 'ti953_FPD3_RX_ID' defined but not used [-Wunused-const-variable=] 101 | static const struct ti953_register_devid ti953_FPD3_RX_ID[] = { | ^~~~~~~~~~~~~~~~ drivers/media/i2c/ti953.h:96:42: warning: 'ti953_init_settings_clk' defined but not used [-Wunused-const-variable=] 96 | static const struct ti953_register_write ti953_init_settings_clk[] = { | ^~~~~~~~~~~~~~~~~~~~~~~ drivers/media/i2c/ti953.h:29:42: warning: 'ti953_init_settings' defined but not used [-Wunused-const-variable=] 29 | static const struct ti953_register_write ti953_init_settings[] = { | ^~~~~~~~~~~~~~~~~~~ vim +/bus_switch +129 drivers/media/i2c/ti960-des.c 1aafb1e0df5527 Ng Khai Wen 2021-07-01 128 d2753af810c799 Ng Khai Wen 2021-07-01 @129 int bus_switch(struct ti960 *va) d2753af810c799 Ng Khai Wen 2021-07-01 130 { d2753af810c799 Ng Khai Wen 2021-07-01 131 int ret; d2753af810c799 Ng Khai Wen 2021-07-01 132 int retry, timeout = 10; d2753af810c799 Ng Khai Wen 2021-07-01 133 struct i2c_client *client = v4l2_get_subdevdata(&va->sd); d2753af810c799 Ng Khai Wen 2021-07-01 134 d2753af810c799 Ng Khai Wen 2021-07-01 135 dev_dbg(&client->dev, "bus switch"); d2753af810c799 Ng Khai Wen 2021-07-01 136 client->addr = 0x70; d2753af810c799 Ng Khai Wen 2021-07-01 137 for (retry = 0; retry < timeout; retry++) { d2753af810c799 Ng Khai Wen 2021-07-01 138 ret = i2c_smbus_write_byte(client, 0x01); d2753af810c799 Ng Khai Wen 2021-07-01 139 if (ret < 0) d2753af810c799 Ng Khai Wen 2021-07-01 140 usleep_range(5000, 6000); d2753af810c799 Ng Khai Wen 2021-07-01 141 else d2753af810c799 Ng Khai Wen 2021-07-01 142 break; d2753af810c799 Ng Khai Wen 2021-07-01 143 } d2753af810c799 Ng Khai Wen 2021-07-01 144 d2753af810c799 Ng Khai Wen 2021-07-01 145 client->addr = TI960_I2C_ADDRESS; d2753af810c799 Ng Khai Wen 2021-07-01 146 if (retry >= timeout) { d2753af810c799 Ng Khai Wen 2021-07-01 147 dev_err(&client->dev, "bus switch failed"); d2753af810c799 Ng Khai Wen 2021-07-01 148 return -EREMOTEIO; d2753af810c799 Ng Khai Wen 2021-07-01 149 } d2753af810c799 Ng Khai Wen 2021-07-01 150 d2753af810c799 Ng Khai Wen 2021-07-01 151 return 0; d2753af810c799 Ng Khai Wen 2021-07-01 152 } d2753af810c799 Ng Khai Wen 2021-07-01 153 :::::: The code at line 129 was first introduced by commit :::::: d2753af810c79927ae6a70fd532a0b19d9816dc5 media: intel-ipu6: add ti960 driver :::::: TO: Ng Khai Wen <khai.wen.ng(a)intel.com&gt; :::::: CC: Pan, Kris <kris.pan(a)intel.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org