Re: [PATCH v4 1/3] mmc: sdhci: Set DMA mask when adding host

From: Arnd Bergmann
Date: Wed Mar 16 2016 - 05:07:23 EST


On Wednesday 16 March 2016 10:43:33 Adrian Hunter wrote:
> > +
> > + /* 32-bit mask as default & fallback */
> > + if (ret) {
> > + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
>
> What happens if device enumeration (e.g. of_dma_configure) has already set a
> more restrictive DMA mask?
>
>

In this case, dma_set_mask_and_coherent() is supposed to check the
bus properties settings again and fail dma_set_mask_and_coherent().

We currently don't do that on ARM, which is a bug.

Arnd