Re: [PATCH v14 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing

[Christoph Hellwig]

On Wed, Jun 23, 2021 at 02:44:34PM -0400, Qian Cai wrote:
> is_swiotlb_force_bounce at /usr/src/linux-next/./include/linux/swiotlb.h:119
> 
> is_swiotlb_force_bounce() was the new function introduced in this patch here.
> 
> +static inline bool is_swiotlb_force_bounce(struct device *dev)
> +{
> +	return dev->dma_io_tlb_mem->force_bounce;
> +}

To me the crash looks like dev->dma_io_tlb_mem is NULL.  Can you
turn this into :

	return dev->dma_io_tlb_mem && dev->dma_io_tlb_mem->force_bounce;

for a quick debug check?