Re: [PATCH] iommu/arm: Allow disabling Qualcomm support in arm_smmu_v3

From: Robin Murphy
Date: Mon Mar 10 2025 - 08:45:07 EST


On 2025-03-10 6:11 am, Aaron Kling via B4 Relay wrote:
From: Aaron Kling <webgeek1234@xxxxxxxxx>

If ARCH_QCOM is enabled when building arm_smmu_v3,

This has nothing to do with SMMUv3, though?

a dependency on
qcom-scm is added, which currently cannot be disabled. Add a prompt to
ARM_SMMU_QCOM to allow disabling this dependency.

Why is that an issue - what problem arises from having the SCM driver enabled? AFAICS it's also selected by plenty of other drivers including pretty fundamental ones like pinctrl. If it is somehow important to exclude the SCM driver, then I can't really imagine what the use-case would be for building a kernel which won't work on most Qualcomm platforms but not simply disabling ARCH_QCOM...

Thanks,
Robin.

Fixes: 0f0f80d9d5db ("iommu/arm: fix ARM_SMMU_QCOM compilation")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Aaron Kling <webgeek1234@xxxxxxxxx>
---
drivers/iommu/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index ec1b5e32b9725bc1104d10e5d7a32af7b211b50a..cca0825551959e3f37cc2ea41aeae526fdb73312 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -381,6 +381,7 @@ config ARM_SMMU_MMU_500_CPRE_ERRATA
config ARM_SMMU_QCOM
def_tristate y
+ prompt "Qualcomm SMMUv3 Support"
depends on ARM_SMMU && ARCH_QCOM
select QCOM_SCM
help

---
base-commit: 1110ce6a1e34fe1fdc1bfe4ad52405f327d5083b
change-id: 20250310-b4-qcom-smmu-d4ccaf66a1ce

Best regards,