Hi Liviu, please try the patch below. Note that this is in top of mainline, as the commit you found already needed another fixup, which has made it to Linus already. -- >From a959cc1a8ee00dcb274922f9d74f6ed632709047 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig <hch@xxxxxx> Date: Fri, 4 Jan 2019 18:31:48 +0100 Subject: dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations We need to return a dma_addr_t even if we don't have a kernel mapping. Do so by consolidating the phys_to_dma call in a single place and jump to it from all the branches that return successfully. Fixes: bfd56cd60521 ("dma-mapping: support highmem in the generic remap allocator") Reported-by: Liviu Dudau <liviu@xxxxxxxxxxx Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- kernel/dma/remap.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index 18cc09fc27b9..7a723194ecbe 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -204,8 +204,7 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, ret = dma_alloc_from_pool(size, &page, flags); if (!ret) return NULL; - *dma_handle = phys_to_dma(dev, page_to_phys(page)); - return ret; + goto done; } page = __dma_direct_alloc_pages(dev, size, dma_handle, flags, attrs); @@ -215,8 +214,10 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, /* remove any dirty cache lines on the kernel alias */ arch_dma_prep_coherent(page, size); - if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) - return page; /* opaque cookie */ + if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) { + ret = page; /* opaque cookie */ + goto done; + } /* create a coherent mapping */ ret = dma_common_contiguous_remap(page, size, VM_USERMAP, @@ -227,9 +228,9 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, return ret; } - *dma_handle = phys_to_dma(dev, page_to_phys(page)); memset(ret, 0, size); - +done: + *dma_handle = phys_to_dma(dev, page_to_phys(page)); return ret; } -- 2.20.1