Re: [RESEND PATCH v2 14/15] ASoC: qcom: apq8096: Add db820c machine driver

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On 03/01/18 19:41, Stephen Boyd wrote:
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
Why do we need to do this? Can you add some sort of comment in the code
about why?
Even though dsp supports 64 bit addresses, but the sid sits at
offset of 32, which brings this restriction of supporting only 32
bit iova.

Doesn't the dsp have an iommu in place to make the address
translation from 64 to 32 bits transparent? I thought this was
what dma-ranges and iommu binding was for, but I'm not well
versed on all the details here.
Thanks for reminding, dma-ranges would work too, I will give that a go in next version.

--srini
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