Re: [PATCH v8 17/26] media/v4l2-core: set pages dirty upon releasing DMA buffers

Andrew Morton
2019-12-10T00:56:36Z

On Mon, 9 Dec 2019 14:53:35 -0800 John Hubbard <jhubbard@nvidia.com> wrote:

> After DMA is complete, and the device and CPU caches are synchronized,
> it's still required to mark the CPU pages as dirty, if the data was
> coming from the device. However, this driver was just issuing a
> bare put_page() call, without any set_page_dirty*() call.
>
> Fix the problem, by calling set_page_dirty_lock() if the CPU pages
> were potentially receiving data from the device.
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: <stable@vger.kernel.org>

What are the user-visible effects of this change?

As it's cc:stable I'd normally send this to Linus within 1-2 weeks, or
sooner. Please confirm that this is a standalone fix, independent of
the rest of this series.