[PATCH v7 08/24] media/v4l2-core: set pages dirty upon releasing DMA buffers

[Christoph Hellwig]

On Wed, Nov 20, 2019 at 11:13:38PM -0800, John Hubbard 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.

Looks good, and like a fix that should be queued up through the media
tree for 5.5 and maybe even added to -stable.

Reviewed-by: Christoph Hellwig <hch at lst.de>