On Mon, Sep 24, 2018 at 10:38:04PM +0200, Arnd Bergmann wrote: > On Tue, Sep 18, 2018 at 3:48 PM Guo Ren <ren_guo@xxxxxxxxx> wrote: > > > > ref: https://lkml.org/lkml/2018/5/18/1068 > > > > map for_cpu for_device unmap > > TO_DEV writeback none writeback none > > TO_CPU invalidate invalidate* invalidate invalidate* > > BIDIR writeback invalidate writeback invalidate > > > > Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx> > > Same comment as for the other patch: Explain why the original > version is wrong first. When giving a reference to some other > discussion, use the "Link" tag above your Signed-off-by line. > To point to a discussion on lkml, lore.kernel.org is the > recommended archive, so it would become > > Link: https://lore.kernel.org/lkml/20180518215548.GH17671@xxxxxxxxxxxxxxxxxxxxx/ Ok, I'll improve the comment: Fixup dma_mapping error in linux-4.19-rc3, and we must implement all DMA_TO_DEVICE/FROM_DEVICE/BIDIRECTIONAL for both sync_dma_for_device/cpu. The implementation of arch should follow the following rules: map for_cpu for_device unmap TO_DEV writeback none writeback none TO_CPU invalidate invalidate* invalidate invalidate* BIDIR writeback invalidate writeback invalidate Link: https://lore.kernel.org/lkml/20180518215548.GH17671@xxxxxxxxxxxxxxxxxxxxx/ Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx> Best Regards Guo Ren
