Hi Heiko, I love your patch! Yet something to improve: [auto build test ERROR on robh/for-next] [also build test ERROR on sparc-next/master net-next/master net/master linus/master v5.8-rc1 next-20200618] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Heiko-Stuebner/add-clkout-suppor... base: https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next config: x86_64-allyesconfig (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 487ca07fcc75d52755c9fe2ee05bcb3b6eeeec44) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): In file included from drivers/net/phy/mscc/mscc_macsec.c:17: struct clk_hw clkout_hw; ^ drivers/net/phy/mscc/mscc.h:371:9: note: forward declaration of 'struct clk_hw' struct clk_hw clkout_hw; ^ 1 error generated. vim +371 drivers/net/phy/mscc/mscc.h 354 355 struct vsc8531_private { 356 int rate_magic; 357 u16 supp_led_modes; 358 u32 leds_mode[MAX_LEDS]; 359 u8 nleds; 360 const struct vsc85xx_hw_stat *hw_stats; 361 u64 *stats; 362 int nstats; 363 /* PHY address within the package. */ 364 u8 addr; 365 /* For multiple port PHYs; the MDIO address of the base PHY in the 366 * package. 367 */ 368 unsigned int base_addr; 369 370 #ifdef CONFIG_COMMON_CLK 372 #endif 373 u32 clkout_rate; 374 int clkout_enabled; 375 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org