On Mon, Jun 13, 2016 at 11:51:08AM +0100, Sudip Mukherjee wrote: > On Mon, Jun 13, 2016 at 10:29:34AM +0100, Mark Brown wrote: > > Right, we've got a couple of obscure architectures with no DMA support > > which are leading to a constant stream of patches like this that are > > being triggered by compile coverage stuff. In situations like this we > > very often provide stubs rather than having to handle this in lots of > > different places in the code. > Ok, I will do that. But I am seeing arch/m32r/include/asm/m32102.h is > defining the DMA Controller registers and also a MAX_DMA_ADDRESS is > defined in dma.h. Doesn't that mean that this arch is capable of DMA? Quite possibly, but they don't seem to implement the standard interfaces for generic code (this sort of thing is quite common for the less widely used architectures sadly).