>>>> + items: >>>> + - enum: >>>> + - nvdia,tegra194-smmu >>>> + - const: arm,mmu-500 > > >>> Is the fallback compatible appropriate here? If software treats this as a >>> standard MMU-500 it will only program the first instance (because the >>> second isn't presented as a separate MMU-500) - is there any way that isn't >>> going to blow up? > > >> When compatible is set to both nvidia,tegra194-smmu and arm,mmu-500, >> implementation override ensure that both instances are programmed. Isn't it? >> I am not sure I follow your comment fully.
>The problem is, if for some reason someone had a Tegra194, but only set the >compatible string to 'arm,mmu-500' it would assume that it was a normal >arm,mmu-500 and only one instance would be programmed. We always want at least >2 of the 3 instances >programmed and so we should only match >'nvidia,tegra194-smmu'. In fact, I think that we also need to update the >arm_smmu_of_match table to add 'nvidia,tegra194-smmu' with the data set to >&arm_mmu500. In that case, new binding "nvidia,smmu-v2" can be added with data set to &arm_mmu500 and enumeration would have nvidia,tegra194-smmu and another variant for next generation SoC in future. -KR -- nvpublic _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
