On Fri, Feb 05, 2021 at 02:26:40PM -0800, Saravana Kannan wrote: > Not all DT bindings are mandatory bindings. Add support for optional DT > bindings and mark iommus, iommu-map, dmas as optional DT bindings. I don't think we can say these are optional or not. It's got to be a driver decision somehow. For example, if IOMMU is optional, what happens with this sequence: driver probes without IOMMU driver calls dma_map_?() IOMMU driver probes h/w accesses DMA buffer --> BOOM!
