From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756179AbZFPI5G (ORCPT ); Tue, 16 Jun 2009 04:57:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755877AbZFPI4d (ORCPT ); Tue, 16 Jun 2009 04:56:33 -0400 Received: from sg2ehsobe003.messaging.microsoft.com ([207.46.51.77]:31761 "EHLO SG2EHSOBE003.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755944AbZFPI4b (ORCPT ); Tue, 16 Jun 2009 04:56:31 -0400 X-SpamScore: 1 X-BigFish: VPS1(zzzz1202hzzz32i17ch62h) X-Spam-TCS-SCL: 1:0 X-WSS-ID: 0KLBQ5V-01-29I-01 From: Joerg Roedel To: Ingo Molnar CC: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Chris Wright , Joerg Roedel Subject: [PATCH 5/6] amd-iommu: set event buffer head and tail to 0 manually Date: Tue, 16 Jun 2009 10:56:14 +0200 Message-ID: <1245142575-7166-6-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.6.3.1 In-Reply-To: <1245142575-7166-1-git-send-email-joerg.roedel@amd.com> References: <1245142575-7166-1-git-send-email-joerg.roedel@amd.com> X-OriginalArrivalTime: 16 Jun 2009 08:56:17.0850 (UTC) FILETIME=[4FB801A0:01C9EE60] MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These registers may contain values from previous kernels. So reset them to known values before enable the event buffer again. Signed-off-by: Joerg Roedel --- arch/x86/kernel/amd_iommu_init.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c index 48a79b9..068a356 100644 --- a/arch/x86/kernel/amd_iommu_init.c +++ b/arch/x86/kernel/amd_iommu_init.c @@ -486,6 +486,10 @@ static void iommu_enable_event_buffer(struct amd_iommu *iommu) memcpy_toio(iommu->mmio_base + MMIO_EVT_BUF_OFFSET, &entry, sizeof(entry)); + /* set head and tail to zero manually */ + writel(0x00, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); + writel(0x00, iommu->mmio_base + MMIO_EVT_TAIL_OFFSET); + iommu_feature_enable(iommu, CONTROL_EVT_LOG_EN); } -- 1.6.3.1