Re: [PATCH v4 2/3] iommu/tegra-smmu: Rework tegra_smmu_probe_device()

[Dmitry Osipenko]

02.10.2020 18:23, Dmitry Osipenko пишет:
> 02.10.2020 09:08, Nicolin Chen пишет:
>> Then when a client gets probed, of_iommu_configure() in
>> iommu core will search DTB for swgroup ID and call ->of_xlate()
>> to prepare an fwspec, similar to tegra_smmu_probe_device() and
>> tegra_smmu_configure(). Then it'll call tegra_smmu_probe_device()
>> again, and this time we shall return smmu->iommu pointer properly.
> 
> I don't quite see where IOMMU core calls of_xlate().
> 
> Have tried to at least boot-test this patch?
> 

I don't see how it ever could work because of_xlate() is only invoked from:

fsl_mc_dma_configure()->of_dma_configure_id()->of_iommu_configure()

Looks like the tegra_smmu_configure() is still needed.

I don't know how sun50i driver could work to be honest. Seems IOMMU is
broken on sun50i, but maybe I'm missing something.

I added Maxime Ripard to this thread, who is the author of the
sun50i-iommu driver.