From ea2e7057c0234cfb8b09467d8f137760d371fc72 Mon Sep 17 00:00:00 2001 From: Sumit Bhattacharya Date: Thu, 24 Nov 2011 00:47:12 +0100 Subject: [PATCH] ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations dma_alloc_coherent wants to split pages after allocation in order to reduce the memory footprint. This does not work well with GFP_COMP pages, so drop this flag before allocation. This patch is ported from arch/avr32 (commit 3611553ef985ef7c5863c8a94641738addd04cff). [swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup] Signed-off-by: Sumit Bhattacharya Tested-by: Varun Colbert Signed-off-by: Stephen Warren Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index ab584569930e..1aa664a1999f 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -332,6 +332,15 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct page *page; void *addr; + /* + * Following is a work-around (a.k.a. hack) to prevent pages + * with __GFP_COMP being passed to split_page() which cannot + * handle them. The real problem is that this flag probably + * should be 0 on ARM as it is not supported on this + * platform; see CONFIG_HUGETLBFS. + */ + gfp &= ~(__GFP_COMP); + *handle = ~0; size = PAGE_ALIGN(size);