Re: [PATCH 2/5] dma-mapping: move the dma_coherent flag to struct device

From: Greg Kroah-Hartman
Date: Tue Sep 11 2018 - 04:19:59 EST


On Tue, Sep 11, 2018 at 08:46:36AM +0200, Christoph Hellwig wrote:
> On Mon, Sep 10, 2018 at 06:13:50PM +0200, Greg Kroah-Hartman wrote:
> > > +#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
> > > + defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
> > > + defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
> > > + bool dma_coherent:1;
> > > +#endif
> >
> > It's just one bit, why not always have it enabled here? If the arch
> > uses it or doesn't, no big deal.
> >
> > Or are you using this to "catch" arches that mess something up?
>
> Yes, that is the intent - I don't want architectures to accidentally
> set it while not selecting the non-coherent infrastructure, as it
> won't have an effect.

Ok, fine with me:
Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>