[RFC PATCH 2/5] dmaengine: allow sun6i-dma for more SoCs

[Maxime Ripard]

On Thu, Nov 24, 2016 at 05:30:45PM +0800, Chen-Yu Tsai wrote:
> On Thu, Nov 24, 2016 at 5:16 PM, Andre Przywara <andre.przywara at arm.com> wrote:
> > Hi,
> >
> > On 24/11/16 04:16, Chen-Yu Tsai wrote:
> >> Hi,
> >>
> >> On Thu, Nov 24, 2016 at 9:17 AM, Andre Przywara <andre.przywara at arm.com> wrote:
> >>> The sun6i DMA driver is used in the Allwinner A64 and H5 SoC, which
> >>> have arm64 capable cores. Add the generic sunxi config symbol to allow
> >>> the driver to be selected by arm64 Kconfigs, which don't feature
> >>> SoC specific MACH_xxxx configs.
> >>>
> >>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> >>> ---
> >>>  drivers/dma/Kconfig | 2 +-
> >>>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> >>> index af63a6b..003c284 100644
> >>> --- a/drivers/dma/Kconfig
> >>> +++ b/drivers/dma/Kconfig
> >>> @@ -157,7 +157,7 @@ config DMA_SUN4I
> >>>
> >>>  config DMA_SUN6I
> >>>         tristate "Allwinner A31 SoCs DMA support"
> >>> -       depends on MACH_SUN6I || MACH_SUN8I || COMPILE_TEST
> >>> +       depends on MACH_SUN6I || MACH_SUN8I || COMPILE_TEST || ARCH_SUNXI
> >>
> >> AFAIK ARCH_SUNXI encompasses/supersedes MACH_SUN*I.
> >> (And I don't have to add MACH_SUN9I later :) )
> >
> > Sure, admittedly it was just a quick hack to get things going.
> > Actually I don't know why we had a *depend* on those MACH_s before. I
> > think technically it does not depend on a certain SoC (having the
> > COMPILE_TEST in there hints on that). So what about:
> 
> It was really because this DMA engine only comes with the later
> SoCs. We have dma-sun4i for the older one.

Indeed.

> But yes, there's no reason why you can't build it for the earlier
> SoC. It just doesn't get used.

I'm still in favor of keeping the depends on. There's no point of
compiling something we know have zero chance of running.

(But that would be (ARCH_SUNXI && ARM64))

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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