imx7: dev->coherent_dma_mask NULL warning

Fabio Estevam festevam at
Wed Aug 18 06:37:38 PDT 2021

Hi Christoph,

On Wed, Aug 18, 2021 at 10:28 AM Christoph Hellwig <hch at> wrote:
> On Wed, Aug 18, 2021 at 06:31:19AM -0300, Fabio Estevam wrote:
> > Correct, on i.MX7 the ath10k Wifi chip connects via SDIO.
> >
> > Is there a way to avoid the WARN_ON_ONCE(!dev->coherent_dma_mask)
> > to happen in this case?
> The way to avoid it is by stoppind to use dma_alloc_attrs/coherent
> on a device that is not DMA capable.

Understood, thanks.

Maybe something like this (untested)?


>From an ath10k driver perspective: would you have any suggestions as
to how to stop calling
dma_alloc_coherent() for the SDIO and USB cases?


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