Re: [PATCH 2/2] swiotlb: Skip cache maintenance on map error

[Christoph Hellwig]

On Tue, Nov 20, 2018 at 02:09:53PM +0000, Robin Murphy wrote:
> If swiotlb_bounce_page() failed, calling arch_sync_dma_for_device() may
> lead to such delights as performing cache maintenance on whatever
> address phys_to_virt(SWIOTLB_MAP_ERROR) looks like, which is typically
> outside the kernel memory map and goes about as well as expected.
> 
> Don't do that.
> 
> Fixes: a4a4330db46a ("swiotlb: add support for non-coherent DMA")
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>

Looks good,

Reviewed-by: Christoph Hellwig <hch@xxxxxx>