Subject: Re: [PATCH v7 07/15] swiotlb: Update is_swiotlb_active to add a struct device argument

From: Christoph Hellwig <[email-masked]>
Date: Thu, 27 May 2021 15:28:22 +0200

> +	if (is_swiotlb_active(NULL)) {

Passing a NULL argument to this doesn't make sense.  They all should have
a struct device at hand, you'll just need to dig for it.

And this function should be about to go away anyway, but until then we
need to do this properly.