On Wed, Sep 29, 2021 at 11:51 AM Will Deacon [off-list ref] wrote:

On Mon, Sep 27, 2021 at 05:22:13PM +0200, Arnd Bergmann wrote:

quoted

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 124c41adeca1..989c83acbfee 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig

@@ -308,7 +308,7 @@ config APPLE_DART
 config ARM_SMMU
      tristate "ARM Ltd. System MMU (SMMU) Support"
      depends on ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64)
-     depends on QCOM_SCM || !QCOM_SCM #if QCOM_SCM=m this can't be =y
+     select QCOM_SCM
      select IOMMU_API
      select IOMMU_IO_PGTABLE_LPAE
      select ARM_DMA_USE_IOMMU if ARM

I don't want to get in the way of this patch because I'm also tired of the
randconfig failures caused by QCOM_SCM. However, ARM_SMMU is applicable to
a wide variety of (non-qcom) SoCs and so it seems a shame to require the
QCOM_SCM code to be included for all of those when it's not strictly needed
at all.

Good point, I agree that needs to be fixed. I think this additional
change should do the trick:

--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig

@@ -308,7 +308,6 @@ config APPLE_DART
 config ARM_SMMU
        tristate "ARM Ltd. System MMU (SMMU) Support"
        depends on ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64)
-       select QCOM_SCM
        select IOMMU_API
        select IOMMU_IO_PGTABLE_LPAE
        select ARM_DMA_USE_IOMMU if ARM

@@ -438,7 +437,7 @@ config QCOM_IOMMU
        # Note: iommu drivers cannot (yet?) be built as modules
        bool "Qualcomm IOMMU Support"
        depends on ARCH_QCOM || (COMPILE_TEST && !GENERIC_ATOMIC64)
-       depends on QCOM_SCM=y
+       select QCOM_SCM
        select IOMMU_API
        select IOMMU_IO_PGTABLE_LPAE
        select ARM_DMA_USE_IOMMU

I'll see if that causes any problems for the randconfig builds.

       Arnd