Hi Laurent, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linux/master] [also build test WARNING on linus/master v5.12-rc2 next-20210309] [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/Laurent-Vivier/virtio-mmio-read-... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 144c79ef33536b4ecb4951e07dbc1f2b7fa99d32 config: x86_64-randconfig-s022-20210310 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-262-g5e674421-dirty # https://github.com/0day-ci/linux/commit/1fd3d4da486545f554eb33663c6afe068... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Laurent-Vivier/virtio-mmio-read-wl-write-wl-are-already-little-endian/20210310-064527 git checkout 1fd3d4da486545f554eb33663c6afe068bbcbcf8 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; "sparse warnings: (new ones prefixed by >>)" drivers/virtio/virtio_mmio.c:171:19: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __le16 [usertype] w @@ got unsigned short @@ drivers/virtio/virtio_mmio.c:171:19: sparse: expected restricted __le16 [usertype] w drivers/virtio/virtio_mmio.c:171:19: sparse: got unsigned short drivers/virtio/virtio_mmio.c:175:19: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __le32 [usertype] l @@ got unsigned int @@ drivers/virtio/virtio_mmio.c:175:19: sparse: expected restricted __le32 [usertype] l drivers/virtio/virtio_mmio.c:175:19: sparse: got unsigned int drivers/virtio/virtio_mmio.c:179:19: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __le32 [addressable] [usertype] l @@ got unsigned int @@ drivers/virtio/virtio_mmio.c:179:19: sparse: expected restricted __le32 [addressable] [usertype] l drivers/virtio/virtio_mmio.c:179:19: sparse: got unsigned int drivers/virtio/virtio_mmio.c:181:19: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __le32 [addressable] [usertype] l @@ got unsigned int @@ drivers/virtio/virtio_mmio.c:181:19: sparse: expected restricted __le32 [addressable] [usertype] l drivers/virtio/virtio_mmio.c:181:19: sparse: got unsigned int drivers/virtio/virtio_mmio.c:215:24: sparse: expected unsigned short val drivers/virtio/virtio_mmio.c:215:24: sparse: got restricted __le16 [addressable] [usertype] w drivers/virtio/virtio_mmio.c:219:24: sparse: expected unsigned int val drivers/virtio/virtio_mmio.c:219:24: sparse: got restricted __le32 [addressable] [usertype] l drivers/virtio/virtio_mmio.c:223:24: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned int val @@ got restricted __le32 [addressable] [usertype] l @@ drivers/virtio/virtio_mmio.c:223:24: sparse: expected unsigned int val drivers/virtio/virtio_mmio.c:223:24: sparse: got restricted __le32 [addressable] [usertype] l drivers/virtio/virtio_mmio.c:225:24: sparse: sparse: incorrect type in argument 1 (different base types) @@ expected unsigned int val @@ got restricted __le32 [addressable] [usertype] l @@ drivers/virtio/virtio_mmio.c:225:24: sparse: expected unsigned int val drivers/virtio/virtio_mmio.c:225:24: sparse: got restricted __le32 [addressable] [usertype] l vim +215 drivers/virtio/virtio_mmio.c 188 189 static void vm_set(struct virtio_device *vdev, unsigned offset, 190 const void *buf, unsigned len) 191 { 192 struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); 193 void __iomem *base = vm_dev->base + VIRTIO_MMIO_CONFIG; 194 u8 b; 195 __le16 w; 196 __le32 l; 197 198 if (vm_dev->version == 1) { 199 const u8 *ptr = buf; 200 int i; 201 202 for (i = 0; i < len; i++) 203 writeb(ptr[i], base + offset + i); 204 205 return; 206 } 207 208 switch (len) { 209 case 1: 210 memcpy(&b, buf, sizeof b); 211 writeb(b, base + offset); 212 break; 213 case 2: 214 memcpy(&w, buf, sizeof w); 216 break; 217 case 4: 218 memcpy(&l, buf, sizeof l); 220 break; 221 case 8: 222 memcpy(&l, buf, sizeof l); 223 writel(l, base + offset); 224 memcpy(&l, buf + sizeof l, sizeof l); 225 writel(l, base + offset + sizeof l); 226 break; 227 default: 228 BUG(); 229 } 230 } 231 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org