diff mbox series

iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context

Message ID 20210106005038.4152731-1-bjorn.andersson@linaro.org (mailing list archive)
State Accepted
Commit aded8c7c2b72f846a07a2c736b8e75bb8cf50a87
Headers show
Series iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context | expand

Commit Message

Bjorn Andersson Jan. 6, 2021, 12:50 a.m. UTC
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(+)

Comments

Will Deacon Jan. 7, 2021, 2:22 p.m. UTC | #1
On Tue, 5 Jan 2021 16:50:38 -0800, Bjorn Andersson wrote:
> 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.
> 
> [...]

Applied to arm64 (for-next/iommu/fixes), thanks!

[1/1] iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context
      https://git.kernel.org/arm64/c/aded8c7c2b72

Cheers,
patchwork-bot+linux-arm-msm@kernel.org March 1, 2021, 7:59 p.m. UTC | #2
Hello:

This patch was applied to qcom/linux.git (refs/heads/for-next):

On Tue,  5 Jan 2021 16:50:38 -0800 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - iommu/arm-smmu-qcom: Initialize SCTLR of the bypass context
    https://git.kernel.org/qcom/c/aded8c7c2b72

You are awesome, thank you!
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diff mbox series

Patch

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);
 	}