From 2c6827e83b8f66d1fe369ee9d0010e0d7c3742c3 Mon Sep 17 00:00:00 2001 From: Sumit Bhattacharya Date: Thu, 13 Oct 2011 17:20:47 +0530 Subject: arm: 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). Change-Id: I455cfdc7a2180b8d9d193da5fc8aaf70f8b94ee2 Signed-off-by: Sumit Bhattacharya Reviewed-on: http://git-master/r/57854 Reviewed-by: Varun Colbert Tested-by: Varun Colbert --- arch/arm/mm/dma-mapping.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 82a093cee09a..93b86e639cf7 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -308,6 +308,13 @@ __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_HUGETLB_PAGE. */ + gfp &= ~(__GFP_COMP); + *handle = ~0; size = PAGE_ALIGN(size); -- cgit v1.2.3