Hi Jacopo, I love your patch! Yet something to improve: [auto build test ERROR on media-tree/master] [also build test ERROR on v5.16-rc5 next-20211215] [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/Jacopo-Mondi/media-adv748x-Add-C... base: git://linuxtv.org/media_tree.git master config: arc-randconfig-r043-20211216 (https://download.01.org/0day-ci/archive/20211217/202112171052.3JgXYSA4-lk...) compiler: arc-elf-gcc (GCC) 11.2.0 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/beac1be47b64ce291e1647699be3f26d8... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jacopo-Mondi/media-adv748x-Add-CSI-2-VC-support/20211217-010519 git checkout beac1be47b64ce291e1647699be3f26d88028b3b # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arc SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/media/i2c/adv748x/adv748x-csi2.c: In function 'adv748x_csi2_init_cfg': 146 | struct v4l2_subdev_route routes[ADV748X_CSI2_STREAMS] = { | ^~~~~~ 152 | .flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ | V4L2_SUBDEV_FORMAT_ACTIVE drivers/media/i2c/adv748x/adv748x-csi2.c:152:34: note: each undeclared identifier is reported only once for each function it appears in 173 | struct v4l2_subdev_krouting routing; | ^~~~~~~ 179 | v4l2_subdev_lock_state(state); | ^~~~~~~~~~~~~~~~~~~~~~ | v4l2_subdev_alloc_state 180 | ret = v4l2_subdev_set_routing(sd, state, &routing); | ^~~~~~~~~~~~~~~~~~~~~~~ | v4l2_subdev_notify 181 | v4l2_subdev_unlock_state(state); | ^~~~~~~~~~~~~~~~~~~~~~~~ | v4l2_subdev_alloc_state drivers/media/i2c/adv748x/adv748x-csi2.c:173:37: warning: unused variable 'routing' [-Wunused-variable] 173 | struct v4l2_subdev_krouting routing; | ^~~~~~~ drivers/media/i2c/adv748x/adv748x-csi2.c:146:34: warning: unused variable 'routes' [-Wunused-variable] 146 | struct v4l2_subdev_route routes[ADV748X_CSI2_STREAMS] = { | ^~~~~~ drivers/media/i2c/adv748x/adv748x-csi2.c: In function 'adv748x_csi2_init': 362 | V4L2_SUBDEV_FL_MULTIPLEXED, | ^~~~~~~~~~~~~~~~~~~~~~~~~~ 379 | ret = v4l2_subdev_init_finalize(&tx->sd); | ^~~~~~~~~~~~~~~~~~~~~~~~~ | v4l2_subdev_init 396 | v4l2_subdev_cleanup(&tx->sd); | ^~~~~~~~~~~~~~~~~~~ | v4l2_subdev_call cc1: some warnings being treated as errors vim +146 drivers/media/i2c/adv748x/adv748x-csi2.c 134 135 /* ----------------------------------------------------------------------------- 136 * v4l2_subdev_pad_ops 137 * 138 * The CSI2 bus pads are ignorant to the data sizes or formats. 139 * But we must support setting the pad formats for format propagation. 140 */ 141 142 static int adv748x_csi2_init_cfg(struct v4l2_subdev *sd, 143 struct v4l2_subdev_state *state) 144 { 145 /* One route for each virtual channel. Route 0 enabled by default. */ 147 { 148 .sink_pad = ADV748X_CSI2_SINK, 149 .sink_stream = 0, 150 .source_pad = ADV748X_CSI2_SOURCE, 151 .source_stream = 0, 153 }, 154 { 155 .sink_pad = ADV748X_CSI2_SINK, 156 .sink_stream = 0, 157 .source_pad = ADV748X_CSI2_SOURCE, 158 .source_stream = 1, 159 }, 160 { 161 .sink_pad = ADV748X_CSI2_SINK, 162 .sink_stream = 0, 163 .source_pad = ADV748X_CSI2_SOURCE, 164 .source_stream = 2, 165 }, 166 { 167 .sink_pad = ADV748X_CSI2_SINK, 168 .sink_stream = 0, 169 .source_pad = ADV748X_CSI2_SOURCE, 170 .source_stream = 3, 171 }, 172 }; 174 int ret; 175 176 routing.num_routes = ADV748X_CSI2_STREAMS; 177 routing.routes = routes; 178 182 183 return ret; 184 } 185 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org