From aded8c7c2b72f846a07a2c736b8e75bb8cf50a87 Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Tue, 5 Jan 2021 16:50:38 -0800 Subject: [PATCH] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context On SM8150 it's occasionally observed that the boot hangs in between the writing of SMEs and context banks in arm_smmu_device_reset(). The problem seems to coincide with a display refresh happening after updating the stream mapping, but before clearing - and there by disabling translation - the context bank picked to emulate translation bypass. Resolve this by explicitly disabling the bypass context already in cfg_probe. Fixes: f9081b8ff593 ("iommu/arm-smmu-qcom: Implement S2CR quirk") Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20210106005038.4152731-1-bjorn.andersson@linaro.org Signed-off-by: Will Deacon --- drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c index 5dff7ff..1b83d14 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c @@ -196,6 +196,8 @@ static int qcom_smmu_cfg_probe(struct arm_smmu_device *smmu) set_bit(qsmmu->bypass_cbndx, smmu->context_map); + arm_smmu_cb_write(smmu, qsmmu->bypass_cbndx, ARM_SMMU_CB_SCTLR, 0); + reg = FIELD_PREP(ARM_SMMU_CBAR_TYPE, CBAR_TYPE_S1_TRANS_S2_BYPASS); arm_smmu_gr1_write(smmu, ARM_SMMU_GR1_CBAR(qsmmu->bypass_cbndx), reg); } -- 2.7.4