Hi "Enrico,

I love your patch! Yet something to improve:

[auto build test ERROR on gpio/for-next]
[also build test ERROR on linux/master linus/master v5.10-rc5 next-20201127]
[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/Enrico-Weigelt-metux-IT-consult/drivers-gpio-add-virtio-gpio-guest-driver/20201128-023506
base:   https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio.git for-next
config: c6x-randconfig-p002-20201128 (attached as .config)
compiler: c6x-elf-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/0day-ci/linux/commit/a134ec4827b0ffb7edd6a292238bd93fb377f127
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Enrico-Weigelt-metux-IT-consult/drivers-gpio-add-virtio-gpio-guest-driver/20201128-023506
        git checkout a134ec4827b0ffb7edd6a292238bd93fb377f127
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=c6x 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> error: include/uapi/linux/virtio_gpio.h: missing "WITH Linux-syscall-note" for SPDX-License-Identifier
   make[2]: *** [scripts/Makefile.headersinst:63: usr/include/linux/virtio_gpio.h] Error 1
   make[2]: Target '__headers' not remade because of errors.
   make[1]: *** [Makefile:1288: headers] Error 2
   arch/c6x/kernel/asm-offsets.c:14:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes]
      14 | void foo(void)
         |      ^~~
   <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:185: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org