Re: [PATCH] lib/scatterlist: Provide a DMA page iterator

[hch@xxxxxx]

On Wed, Jan 16, 2019 at 07:28:13AM +0000, Koenig, Christian wrote:
> To summarize once more: We have an array of struct pages and want to 
> coherently map that to a device.

And the answer to that is very simple: you can't.  What is so hard
to understand about?  If you want to map arbitrary memory it simply
can't be done in a coherent way on about half of our platforms.

> If that is not possible because of whatever reason we want to get an 
> error code or even not load the driver from the beginning.

That is a bullshit attitude.  Just like everyone else makes their
drivers work you should not be lazy.

> > bool dma_streaming_is_coherent(const struct device *)
> >
> > API to help us decide when to load or not.
> 
> Yes, please.

Hell no.