Hi Jacob, I love your patch! Perhaps something to improve: [auto build test WARNING on iommu/next] [also build test WARNING on linux/master linus/master v5.9-rc1 next-20200821] [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/Jacob-Pan/IOASID-extensions-for-guest-SVA/20200822-123111 base: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git next config: x86_64-allyesconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # save the attached .config to linux build tree make W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): drivers/iommu/ioasid.c: In function 'ioasid_get_capacity': >> drivers/iommu/ioasid.c:50:10: warning: old-style function definition [-Wold-style-definition] 50 | ioasid_t ioasid_get_capacity() | ^~~~~~~~~~~~~~~~~~~ drivers/iommu/ioasid.c: At top level: >> drivers/iommu/ioasid.c:577:6: warning: no previous prototype for 'ioasid_set_get' [-Wmissing-prototypes] 577 | void ioasid_set_get(struct ioasid_set *set) | ^~~~~~~~~~~~~~ # https://github.com/0day-ci/linux/commit/59b6f319b27588b2a8a0268a4f4f09f7be458861 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jacob-Pan/IOASID-extensions-for-guest-SVA/20200822-123111 git checkout 59b6f319b27588b2a8a0268a4f4f09f7be458861 vim +50 drivers/iommu/ioasid.c 49 > 50 ioasid_t ioasid_get_capacity() 51 { 52 return ioasid_capacity; 53 } 54 EXPORT_SYMBOL_GPL(ioasid_get_capacity); 55 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org