Re: [PATCH 1/2] iommu/mediatek: select ARM_DMA_USE_IOMMU

[Robin Murphy]

On 29/02/16 11:29, Arnd Bergmann wrote:
> On Monday 29 February 2016 11:22:24 Robin Murphy wrote:
> > > > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> > > > > index b325954cf8f8..ea0998921702 100644
> > > > > --- a/drivers/iommu/Kconfig
> > > > > +++ b/drivers/iommu/Kconfig
> > > > > @@ -341,6 +341,7 @@ config MTK_IOMMU
> > > > >      bool "MTK IOMMU Support"
> > > > >      depends on ARM || ARM64
> > > > >      depends on ARCH_MEDIATEK || COMPILE_TEST
> > > > > +   select ARM_DMA_USE_IOMMU
> > > >
> > > > If going down this route, I'd be inclined to add an "if ARM" there, just
> > > > for clarity.
> > >
> > > That would run into the NEED_SG_DMA_LENGTH problem on other architectures
> > > that don't already set it, right?
> >
> > Sorry, I'm lost - wouldn't "depends on ARM || ARM64" make other
> > architectures moot? arm64 already has NEED_SG_DMA_LENGTH=y by default.
>
> Nevermind, I didn't notice the dependency on the architecture.
>
> What is keeping us from having 'depends on ARM || ARM64 || COMPILE_TEST'?

IIRC it got changed because the kbuild test robot was consistently 
blowing up due to missing definitions on things like parisc.

Robin.

> I assume it doesn't work yet, but it would be nice to get that done
> at some point so we can take advantage of automated build testing like
> coverity.
>
> 	Arnd