Re: [PATCH] swiotlb: Fix unexpected swiotlb_alloc_coherent() failures

[Christoph Hellwig]

On Tue, Apr 10, 2018 at 06:50:04PM +0100, Robin Murphy wrote:
> In the first one, the machine appears to have enough RAM that most of it is 
> beyond the device's 36-bit DMA mask, thus it's fairly likely for the 
> initial direct alloc to come back with something unsuitable.

But we should try a GFP_DMA32 allocation first, so this is a bit
surprising.