On Mon, Sep 24, 2018 at 10:38:04PM +0200, Arnd Bergmann wrote:
> On Tue, Sep 18, 2018 at 3:48 PM Guo Ren <[email protected]> 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 <[email protected]>
>
> 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/[email protected]/
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/[email protected]/
Signed-off-by: Guo Ren <[email protected]>
Best Regards
Guo Ren
