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Re: [PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for NO_DMA=y

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On Sun, Jul 9, 2017 at 9:33 PM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> Adding a dummy for set_dma_ops() allows to compile (sub)drivers that
> don't actually use the DMA API, but propagate DMA ops configuration to a
> second driver that may or may not use the DMA API.  Of course the second
> driver does have to depend on HAS_DMA if it uses the DMA API.
>
> An example is commit 5567e989198b5a8d ("fsl/fman: propagate dma_ops").
>
> This allows to revert commit 85688d9adf685572 ("fsl/fman: add dependency
> on HAS_DMA").
>
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

I can't think of any correct use case for this new helper. IMO a device
driver should never set the dma_map_ops for any device, and we should
instead for the fman driver correctly.

       Arnd

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[PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for NO_DMA=y Geert Uytterhoeven <geert@linux-m68k.org> - 2017-07-09 21:40 +0200
  Re: [PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for NO_DMA=y Arnd Bergmann <arnd@arndb.de> - 2017-07-10 10:00 +0200
  Re: [PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for         NO_DMA=y Christoph Hellwig <hch@lst.de> - 2017-07-10 17:00 +0200
    Re: [PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for NO_DMA=y Robin Murphy <robin.murphy@arm.com> - 2017-07-10 17:40 +0200
      Re: [PATCH/RFC] dma-mapping: Provide dummy set_dma_ops() for         NO_DMA=y Christoph Hellwig <hch@lst.de> - 2017-07-11 16:10 +0200

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