On Tue, Sep 06, 2022 at 03:34:02PM +0300, Oded Gabbay wrote: > > > > > + /* > > > > > + * Since the memory being mapped is a device memory it could never be in > > > > > + * CPU caches. > > > > > + */ > > > > DMA_ATTR_SKIP_CPU_SYNC doesn't even apply to dma_map_resource, not sure > > > > where this wisdom comes from. > > > > Habana driver > I hate to throw the ball at someone else, but I actually copied the > code from the amdgpu driver, from amdgpu_vram_mgr_alloc_sgt() iirc. > And if you remember Jason, you asked why we use this specific define > in the original review you did and I replied the following (to which > you agreed and that's why we added the comment): Yes, I remember, but Christophs remark is that DMA_ATTR_SKIP_CPU_SYNC doesn't even do anything when passed to dma_map_resource(). The only attr that seems to be used is DMA_ATTR_PRIVILEGED from what I can see. Jason
