Hi Sui, Thank you for the patch! Yet something to improve: [auto build test ERROR on drm/drm-next] [also build test ERROR on robh/for-next v5.17-rc5 next-20220222] [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/Sui-Jingfeng/drm-lsdc-add-drm-driver-for-loongson-display-controller/20220220-225801 base: git://anongit.freedesktop.org/drm/drm drm-next config: riscv-randconfig-r012-20220221 (https://download.01.org/0day-ci/archive/20220223/202202231909.8x2nM3si-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e) 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://github.com/0day-ci/linux/commit/3891cda03ed77e66fafaf7cfe075042e13f20173 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Sui-Jingfeng/drm-lsdc-add-drm-driver-for-loongson-display-controller/20220220-225801 git checkout 3891cda03ed77e66fafaf7cfe075042e13f20173 # 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=riscv SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): >> ld.lld: error: undefined symbol: ttm_bo_init >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_create) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_bo_put >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_put) in archive drivers/built-in.a >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_object_free) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_tt_init >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(bo_driver_ttm_tt_create) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_tt_fini >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(bo_driver_ttm_tt_destroy) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_bo_move_memcpy >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(bo_driver_move) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_bo_vunmap >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_bo_driver_move_notify) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: drm_gem_ttm_print_info >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_object_funcs) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: drm_gem_ttm_mmap >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_object_funcs) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_bo_eviction_valuable >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(bo_driver) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: drm_gem_ttm_dumb_map_offset >>> referenced by lsdc_drv.c >>> gpu/drm/lsdc/lsdc_drv.o:(lsdc_vram_driver_stub) in archive drivers/built-in.a -- >> ld.lld: error: undefined symbol: ttm_bo_move_to_lru_tail >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_pin) in archive drivers/built-in.a >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_unpin) in archive drivers/built-in.a >>> referenced by drm_gem_vram_helper.c >>> gpu/drm/drm_gem_vram_helper.o:(drm_gem_vram_vmap) in archive drivers/built-in.a >>> referenced 1 more times .. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx