Re: [PATCH 06/12] dma-mapping: improve selection of dma_declare_coherent availability

From: Christoph Hellwig
Date: Wed Feb 13 2019 - 13:24:40 EST


On Tue, Feb 12, 2019 at 02:40:23PM -0600, Rob Herring wrote:
> > diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
> > index 3607fd2810e4..f8c66a9472a4 100644
> > --- a/drivers/of/Kconfig
> > +++ b/drivers/of/Kconfig
> > @@ -43,6 +43,7 @@ config OF_FLATTREE
> >
> > config OF_EARLY_FLATTREE
> > bool
> > + select DMA_DECLARE_COHERENT
>
> Is selecting DMA_DECLARE_COHERENT okay on UML? We run the unittests with UML.

No, that will fail with undefined references to memunmap.

I gues this needs to be

select DMA_DECLARE_COHERENT if HAS_DMA

> Maybe we should just get rid of OF_RESERVED_MEM. If we support booting
> from DT, then it should always be enabled anyways.

Fine with me. Do you want me to respin the series to just remove
it?