[PATCH] arm64: dts: juno: Enable some SMMUs

Sudeep Holla sudeep.holla at arm.com
Fri May 19 10:42:56 PDT 2017



On 18/05/17 13:23, Robin Murphy wrote:
> The IOMMU-backed DMA API support has now been in place for a while and
> proven stable, so there's no real need to keep most of Juno's SMMUs
> disabled. The USB, HDLCDs, and CoreSight ETR all just need to map RAM
> buffers for DMA - enabling their SMMUs obviates CPU bounce buffering for
> USB's streaming DMA to the upper memory bank, and lets the other two
> allocate their relatively large coherent buffers without pressuring CMA.
> 
> Some more software work is still needed for the DMA-330 and PCIe before
> those can accommodate SMMU translation correctly in all cases, so we
> leave those alone for now.
> 

Queued for v4.13 [1]

IIUC, it's not a fix and can wait for v4.13. Let me know if that's not
the case.

-- 
Regards,
Sudeep

[1] https://git.kernel.org/sudeep.holla/linux/h/for-next/juno-updates



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