Hi Ikjoon, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on spi/for-next] [also build test WARNING on next-20200910] [cannot apply to robh/for-next v5.9-rc4] [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/Ikjoon-Jang/Add-36bit-dma-suppor... base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next config: arm-randconfig-r035-20200909 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0a5dc7effb191eff740e0e7ae7bd8e1f6bdb3ad9) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang 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 >>): writel(dma_addr >> 32, sp->base + MTK_NOR_REG_DMA_DADR_HB); ^ ~~ arch/arm/include/asm/io.h:307:51: note: expanded from macro 'writel' #define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); }) ^ arch/arm/include/asm/io.h:299:68: note: expanded from macro 'writel_relaxed' #define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c) ^ include/uapi/linux/byteorder/little_endian.h:33:51: note: expanded from macro '__cpu_to_le32' #define __cpu_to_le32(x) ((__force __le32)(__u32)(x)) ^ drivers/spi/spi-mtk-nor.c:287:30: warning: shift count >= width of type [-Wshift-count-overflow] writel((dma_addr + length) >> 32, sp->base + MTK_NOR_REG_DMA_END_DADR_HB); ^ ~~ arch/arm/include/asm/io.h:307:51: note: expanded from macro 'writel' #define writel(v,c) ({ __iowmb(); writel_relaxed(v,c); }) ^ arch/arm/include/asm/io.h:299:68: note: expanded from macro 'writel_relaxed' #define writel_relaxed(v,c) __raw_writel((__force u32) cpu_to_le32(v),c) ^ include/uapi/linux/byteorder/little_endian.h:33:51: note: expanded from macro '__cpu_to_le32' #define __cpu_to_le32(x) ((__force __le32)(__u32)(x)) ^ 2 warnings generated. # https://github.com/0day-ci/linux/commit/d6ccdab2988e8bf7aa66cc57daeac5e1a... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Ikjoon-Jang/Add-36bit-dma-support-to-mediatek-spi-nor-controller/20200910-121600 git checkout d6ccdab2988e8bf7aa66cc57daeac5e1a7e399cc vim +286 drivers/spi/spi-mtk-nor.c 266 267 static int mtk_nor_read_dma(struct mtk_nor *sp, u32 from, unsigned int length, 268 u8 *buffer) 269 { 270 int ret = 0; 271 ulong delay; 272 u32 reg; 273 dma_addr_t dma_addr; 274 275 dma_addr = dma_map_single(sp->dev, buffer, length, DMA_FROM_DEVICE); 276 if (dma_mapping_error(sp->dev, dma_addr)) { 277 dev_err(sp->dev, "failed to map dma buffer.\n"); 278 return -EINVAL; 279 } 280 281 writel(from, sp->base + MTK_NOR_REG_DMA_FADR); 282 writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR); 283 writel(dma_addr + length, sp->base + MTK_NOR_REG_DMA_END_DADR); 284 285 if (sp->high_dma) { 287 writel((dma_addr + length) >> 32, sp->base + MTK_NOR_REG_DMA_END_DADR_HB); 288 } 289 290 if (sp->has_irq) { 291 reinit_completion(&sp->op_done); 292 mtk_nor_rmw(sp, MTK_NOR_REG_IRQ_EN, MTK_NOR_IRQ_DMA, 0); 293 } 294 295 mtk_nor_rmw(sp, MTK_NOR_REG_DMA_CTL, MTK_NOR_DMA_START, 0); 296 297 delay = CLK_TO_US(sp, (length + 5) * BITS_PER_BYTE); 298 299 if (sp->has_irq) { 300 if (!wait_for_completion_timeout(&sp->op_done, 301 (delay + 1) * 100)) 302 ret = -ETIMEDOUT; 303 } else { 304 ret = readl_poll_timeout(sp->base + MTK_NOR_REG_DMA_CTL, reg, 305 !(reg & MTK_NOR_DMA_START), delay / 3, 306 (delay + 1) * 100); 307 } 308 309 dma_unmap_single(sp->dev, dma_addr, length, DMA_FROM_DEVICE); 310 if (ret < 0) 311 dev_err(sp->dev, "dma read timeout.\n"); 312 313 return ret; 314 } 315 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org