From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: [PATCH 13/13] iommu/arm-smmu: Treat unknown OAS as 48-bit Date: Mon, 3 Aug 2015 14:25:55 +0100 Message-ID: <1438608355-7335-14-git-send-email-will.deacon@arm.com> References: <1438608355-7335-1-git-send-email-will.deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1438608355-7335-1-git-send-email-will.deacon-5wv7dgnIgG8@public.gmane.org> 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: jroedel-l3A5Bk7waGM@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, Will Deacon , laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org A late change to the SMMUv3 architecture ensures that the OAS field will be monotonically increasing, so we can assume that an unknown OAS is at least 48-bit and use that, rather than fail the device probe. Signed-off-by: Will Deacon --- drivers/iommu/arm-smmu-v3.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c index 15fb669282b4..a435e706226a 100644 --- a/drivers/iommu/arm-smmu-v3.c +++ b/drivers/iommu/arm-smmu-v3.c @@ -2528,12 +2528,11 @@ static int arm_smmu_device_probe(struct arm_smmu_device *smmu) case IDR5_OAS_44_BIT: smmu->oas = 44; break; + default: + dev_info(smmu->dev, + "unknown output address size. Truncating to 48-bit\n"); case IDR5_OAS_48_BIT: smmu->oas = 48; - break; - default: - dev_err(smmu->dev, "unknown output address size!\n"); - return -ENXIO; } /* Set the DMA mask for our table walker */ -- 2.1.4