From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH] Revert "iommu/amd: Don't allocate with __GFP_ZERO in alloc_coherent" Date: Tue, 2 Jun 2015 08:45:16 +0200 Message-ID: <1433227516-30207-1-git-send-email-joro@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Cc: Joerg Roedel , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: iommu@lists.linux-foundation.org From: Joerg Roedel This reverts commit 5fc872c7323534e8f7dc21bab635e7a9b9659e07. The DMA-API does not strictly require that the memory returned by dma_alloc_coherent is zeroed out. For that another function (dma_zalloc_coherent) should be used. But all other x86 DMA-API implementation I checked zero out the memory, so that some drivers rely on it and break when it is not. It seems the (driver-)world is not yet ready for this change, so revert it. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index e43d489..e1c7e9e 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -2930,6 +2930,7 @@ static void *alloc_coherent(struct device *dev, size_t size, size = PAGE_ALIGN(size); dma_mask = dev->coherent_dma_mask; flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32); + flag |= __GFP_ZERO; page = alloc_pages(flag | __GFP_NOWARN, get_order(size)); if (!page) { -- 1.8.4.5