Re: [PATCH v2] arm64: do not set dma masks that device connection can't handle
From: Nikita Yushchenko
Date: Tue Jan 10 2017 - 09:02:34 EST
>> What issue "IOMMU doesn't solve"?
>>
>> Issue I'm trying to address is - inconsistency within swiotlb
>> dma_map_ops, where (1) any wide mask is silently accepted, but (2) then
>> mask is used to decide if bounce buffers are needed or not. This
>> inconsistency causes NVMe+R-Car cobmo not working (and breaking memory
>> instead).
>
> The fundamental underlying problem is the "any wide mask is silently
> accepted" part, and that applies equally to IOMMU ops as well.
Is just posted version better?
It should cover iommu case as well.
Nikita