Re: [PATCH 2/3] Add swiotlb offset preserving mapping when dma_dma_parameters->page_offset_mask is non zero.

Keith Busch
2021-01-28T17:37:12Z

On Thu, Jan 28, 2021 at 12:15:28PM -0500, Konrad Rzeszutek Wilk wrote:
> On Wed, Jan 27, 2021 at 04:38:28PM -0800, Jianxiong Gao wrote:
> > For devices that need to preserve address offset on mapping through
> > swiotlb, this patch adds offset preserving based on page_offset_mask
> > and keeps the offset if the mask is non zero. This is needed for
> > device drivers like NVMe.
>
> <scratches his head>
>
> Didn't you send this patch like a month ago and someone pointed
> out that the right fix would be in the NVMe driver?
>
> Is there an issue with fixing the NVMe driver?

You got it backwards. The initial "fix" used a flag specific to the nvme
driver, and it was pointed out that it should just be the generic
behaviour.