Hi Tudor, First bad commit (maybe != root cause): tree: https://github.com/ambarus/linux-0day v5.10-atmel-qspi-under-spi-nor head: fe0f9562057be30db3f6282b0809e3243bd5235d commit: e228de6d80cb2ade5118680dd7721f2966bd31d3 [23/35] Revert "spi: Add QuadSPI driver for Atmel SAMA5D2" config: arm-allyesconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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/ambarus/linux-0day/commit/e228de6d80cb2ade5118680dd772... git remote add ambarus https://github.com/ambarus/linux-0day git fetch --no-tags ambarus v5.10-atmel-qspi-under-spi-nor git checkout e228de6d80cb2ade5118680dd7721f2966bd31d3 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm 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 >>): 340 | const char *atmel_qspi_get_name(struct spi_mem *spimem) | ^~~~~~~~~~~~~~~~~~~ vim +/atmel_qspi_get_name +340 drivers/mtd/spi-nor/atmel-quadspi.c d5433def31531bd drivers/mtd/spi-nor/atmel-quadspi.c Piotr Bugalski 2018-11-05 339 9e6be35cfd327c7 drivers/spi/atmel-quadspi.c Tudor Ambarus 2020-11-04 @340 const char *atmel_qspi_get_name(struct spi_mem *spimem) d5433def31531bd drivers/mtd/spi-nor/atmel-quadspi.c Piotr Bugalski 2018-11-05 341 { d5433def31531bd drivers/mtd/spi-nor/atmel-quadspi.c Piotr Bugalski 2018-11-05 342 return dev_name(spimem->spi->dev.parent); d5433def31531bd drivers/mtd/spi-nor/atmel-quadspi.c Piotr Bugalski 2018-11-05 343 } d5433def31531bd drivers/mtd/spi-nor/atmel-quadspi.c Piotr Bugalski 2018-11-05 344 :::::: The code at line 340 was first introduced by commit :::::: 9e6be35cfd327c7f0397a1bcc3839307f10b9917 Revert "spi: atmel-quadspi: Make atmel_qspi_get_name static" :::::: TO: Tudor Ambarus <tudor.ambarus(a)microchip.com&gt; :::::: CC: Tudor Ambarus <tudor.ambarus(a)microchip.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org