Hi Richard, FYI, the error/warning still remains. tree: https://github.com/Freescale/linux-fslc pr/257 head: 5df3672236fb7ca1b04a8e8fa65bf039400b5020 commit: d39a68543c7002b7abd7f9df6d8f26fedda72ea5 [8338/17025] MGS-5565-1 staging: android: ion: Flush outer cache after zero CMA allocated memory config: i386-allyesconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://github.com/Freescale/linux-fslc/commit/d39a68543c7002b7abd7f9df6d... git remote add freescale-fslc https://github.com/Freescale/linux-fslc git fetch --no-tags freescale-fslc pr/257 git checkout d39a68543c7002b7abd7f9df6d8f26fedda72ea5 # save the attached .config to linux build tree make W=1 ARCH=i386 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 >>): drivers/staging/android/ion/ion_cma_heap.c: In function 'ion_cma_allocate': 65 | __flush_dcache_area(vaddr,PAGE_SIZE); | ^~~~~~~~~~~~~~~~~~~ | flush_dcache_page cc1: some warnings being treated as errors Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for IMX_IRQSTEER Depends on ARCH_MXC || COMPILE_TEST Selected by - DRM_IMX_DCSS && HAS_IOMEM vim +65 drivers/staging/android/ion/ion_cma_heap.c 57 58 while (nr_clear_pages > 0) { 59 void *vaddr = kmap_atomic(page); 60 61 memset(vaddr, 0, PAGE_SIZE); 62 #ifdef CONFIG_ARM 63 __cpuc_flush_dcache_area(vaddr,PAGE_SIZE); 64 #else 66 #endif 67 kunmap_atomic(vaddr); 68 page++; 69 nr_clear_pages--; 70 } 71 #ifdef CONFIG_ARM 72 outer_flush_range(base, end); 73 #endif 74 } else { 75 void *ptr = page_address(pages); 76 memset(ptr, 0, size); 77 #ifdef CONFIG_ARM 78 __cpuc_flush_dcache_area(ptr,size); 79 outer_flush_range(__pa(ptr), __pa(ptr) + size); 80 #else 81 __flush_dcache_area(ptr,size); 82 #endif 83 } 84 85 table = kmalloc(sizeof(*table), GFP_KERNEL); 86 if (!table) 87 goto err; 88 89 ret = sg_alloc_table(table, 1, GFP_KERNEL); 90 if (ret) 91 goto free_mem; 92 93 sg_set_page(table->sgl, pages, size, 0); 94 95 buffer->priv_virt = pages; 96 buffer->sg_table = table; 97 return 0; 98 99 free_mem: 100 kfree(table); 101 err: 102 cma_release(cma_heap->cma, pages, nr_pages); 103 return -ENOMEM; 104 } 105 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org