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From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
	linux-arm-kernel@lists.infradead.org,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	linux-arm-msm@vger.kernel.org
Subject: [PATCH] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context
Date: Tue,  5 Jan 2021 16:50:38 -0800	[thread overview]
Message-ID: <20210106005038.4152731-1-bjorn.andersson@linaro.org> (raw)

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 <bjorn.andersson@linaro.org>
---
 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 5dff7ffbef11..1b83d140742f 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);
 	}
-- 
2.29.2


WARNING: multiple messages have this Message-ID (diff)
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: linux-arm-msm@vger.kernel.org, iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context
Date: Tue,  5 Jan 2021 16:50:38 -0800	[thread overview]
Message-ID: <20210106005038.4152731-1-bjorn.andersson@linaro.org> (raw)

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 <bjorn.andersson@linaro.org>
---
 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 5dff7ffbef11..1b83d140742f 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);
 	}
-- 
2.29.2

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID (diff)
From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Will Deacon <will@kernel.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: linux-arm-msm@vger.kernel.org,
	Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>,
	iommu@lists.linux-foundation.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context
Date: Tue,  5 Jan 2021 16:50:38 -0800	[thread overview]
Message-ID: <20210106005038.4152731-1-bjorn.andersson@linaro.org> (raw)

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 <bjorn.andersson@linaro.org>
---
 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 5dff7ffbef11..1b83d140742f 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);
 	}
-- 
2.29.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2021-01-06  0:51 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-06  0:50 Bjorn Andersson [this message]
2021-01-06  0:50 ` [PATCH] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context Bjorn Andersson
2021-01-06  0:50 ` Bjorn Andersson
2021-01-07 14:22 ` Will Deacon
2021-01-07 14:22   ` Will Deacon
2021-01-07 14:22   ` Will Deacon
2021-03-01 19:59 ` patchwork-bot+linux-arm-msm

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