Re: [PATCH 1/5] iommu: Replace uses of IOMMU_CAP_CACHE_COHERENCY with dev_is_dma_coherent()

Christoph Hellwig
2022-04-06T17:36:58Z

On Wed, Apr 06, 2022 at 11:14:46AM -0300, Jason Gunthorpe wrote:
> Really? It is the only condition that dma_info_to_prot() tests to
> decide of IOMMU_CACHE is used or not, so you are saying that there is
> a condition where a device can be attached to an iommu_domain and
> dev_is_dma_coherent() returns the wrong information? How does
> dma-iommu.c safely use it then?

arm does not use dma-iommu.c