On Tue, Feb 05, 2019 at 10:20:32PM +1100, Michael Ellerman wrote: > get_dma_ops() falls into arch-dependant get_arch_dma_ops(), which > historically returns NULL on PowerPC. Therefore dma_set_mask() fails. > This affects Switchtec (and probably other) NTB devices, that they fail > to initialize. > The proposed patch should fix the issue.
I'm not a fan of this. powerpc, just like arm64 for example has required that we set a specific per-device dma ops, which keeps the assignments clear. Where do the NTB devices come from? Might be worth adding the NTB maintainers to the CC list and maybe linux-iommu.
