On Tue, Feb 12, 2019 at 08:20:46PM +0100, Stefan Agner wrote:

> > I dropped both patches from my tree.

> I think this is the wrong approach to disable DMA on those devices. The
> device tree is supposed to describe the complete hardware. If the driver
> is not ready to support DMA for that particular variant, we should add
> this information in the driver. We have compatible strings for i.MX
> 6UL/i.MX 7 to disable DMA accordingly.

Yes, that seems sensible - it's vanishingly unlikely that there's any
problem in the hardware here, it's software bugs and quirking in the
driver seems better than changing the DT.