[PATCH 13/13] iommu/arm-smmu: Treat unknown OAS as 48-bit

[Will Deacon]

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 <will.deacon at arm.com>
---
 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