Re: [PATCH v2] iommu/arm-smmu: disable PRR on SM8250
From: Rob Clark <hidden>
Date: 2025-07-05 18:05:16
Also in:
linux-arm-msm, linux-iommu, lkml
On Sat, Jul 5, 2025 at 9:08 AM Dmitry Baryshkov [off-list ref] wrote:
On SM8250 / QRB5165-RB5 using PRR bits resets the device, most likely
because of the hyp limitations. Disable PRR support on that platform.
Fixes: 7f2ef1bfc758 ("iommu/arm-smmu: Add support for PRR bit setup")
Signed-off-by: Dmitry Baryshkov <redacted>Reviewed-by: Rob Clark <robin.clark@oss.qualcomm.com>
quoted hunk ↗ jump to hunk
--- I currently don't have access to other devices from these generations. It might be necessary to apply the same workaround to other platforms. --- Changes in v2: - Simplify the workaround as the issue seems to be limited to SM8250 only (Rob) - Link to v1: https://lore.kernel.org/r/20250705-iommu-fix-prr-v1-1-ef725033651c@oss.qualcomm.com (local) --- drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c index 62874b18f6459ad9a8b0542ab81c24e3e745c53d..53d88646476e9f193a6275d9c3ee3d084c215362 100644 --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c@@ -355,7 +355,8 @@ static int qcom_adreno_smmu_init_context(struct arm_smmu_domain *smmu_domain, priv->set_prr_addr = NULL; if (of_device_is_compatible(np, "qcom,smmu-500") && - of_device_is_compatible(np, "qcom,adreno-smmu")) { + !of_device_is_compatible(np, "qcom,sm8250-smmu-500") && + of_device_is_compatible(np, "qcom,adreno-smmu")) { priv->set_prr_bit = qcom_adreno_smmu_set_prr_bit; priv->set_prr_addr = qcom_adreno_smmu_set_prr_addr; }--- base-commit: 7244e36657076b597ac21d118be9c0b0f15fc622 change-id: 20250705-iommu-fix-prr-600451b1d304 Best regards, -- With best wishes Dmitry