On Tue, Sep 26, 2017 at 09:48:01AM +0800, 陈华才 wrote: > Hi, Christoph, > > Can I put the declaration in asm/dma-coherence.h? Generally something not expose to the rest of the kernel (that is not in arch/mips/include/) would be preferred, but in the end the architecture maintainer will have to decide. > And, last time you said it is OK to pass a NULL to dma_get_cache_alignment() and cc all driver maintainers. I have do so. No, I asked you to converted everything to pass the struct device and cc the driver maintainers.