Messages in this thread | | | Subject | Re: [PATCH 0/2] iommu/arm-smmu: Add an optional "input-address-size" property | From | Robin Murphy <> | Date | Fri, 11 Oct 2019 10:16:28 +0100 |
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On 2019-10-11 4:46 am, Nicolin Chen wrote: > This series of patches add an optional DT property to allow an SoC to > specify how many bits being physically connected to its SMMU instance, > depending on the SoC design.
This has come up before, and it doesn't work in general because a single SMMU instance can have many master interfaces, with potentially different sizes of address bus wired up to each. It's also a conceptually-wrong approach anyway, since this isn't a property of the SMMU; it's a property of the interconnect(s) upstream of the SMMU.
IIRC you were working on Tegra - if so, Thierry already has a plan, see this thread: https://lore.kernel.org/linux-arm-kernel/20190930133510.GA1904140@ulmo/
Robin.
> > Nicolin Chen (2): > dt-bindings: arm-smmu: Add an optional "input-address-size" property > iommu/arm-smmu: Read optional "input-address-size" property > > Documentation/devicetree/bindings/iommu/arm,smmu.txt | 7 +++++++ > drivers/iommu/arm-smmu.c | 10 ++++++++-- > 2 files changed, 15 insertions(+), 2 deletions(-) >
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