Unexpectedly dma_ops is NULL in struct device

[Logan Gunthorpe]

On 15/11/18 03:05 AM, Alexander Fomichev wrote:
> This issue makes functions dma_set_mask() and dma_set_coherent_mask() and dma_alloc_coherent() fail in ntb_hw_switchtec. And the driver can't start on powerpc.

I don't know a lot about powerpc in this area, but a quick peek shows
that dma_set_mask() does some platform specific stuff so it would
definitely help if you can let us know more about your hardware.

On one platform I looked at, it seems that dma_set_mask() sets the
dma_ops for the device, so the fact that it is NULL at that point is not
likely the issue. It's probably some platform specific bug that's
causing this.

Logan