From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754880AbbFBGpo (ORCPT ); Tue, 2 Jun 2015 02:45:44 -0400 Received: from 8bytes.org ([81.169.241.247]:57231 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752666AbbFBGpf (ORCPT ); Tue, 2 Jun 2015 02:45:35 -0400 From: Joerg Roedel To: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, 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> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.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