Hi all, this is another attempt to make sure the dma_mask pointer is always initialized for platform devices. Not doing so lead to lots of boilerplate code, and makes platform devices different from all our major busses like PCI where we always set up a dma_mask. In the long run this should also help to eventually make dma_mask a scalar value instead of a pointer and remove even more cruft. The bigger blocker for this last time was the fact that the usb subsystem uses the presence or lack of a dma_mask to check if the core should do dma mapping for the driver, which is highly unusual. So we fix this first. Note that this has some overlap with the pending desire to use the proper dma_mmap_coherent helper for mapping usb buffers. The first two patches from this series should probably go into 5.3 and then uses as the basis for the decision to use dma_mmap_coherent.
