From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH v7 08/24] media/v4l2-core: set pages dirty upon releasing
 DMA buffers
Date: Thu, 21 Nov 2019 00:09:03 -0800
Message-ID: <20191121080903.GE30991@infradead.org>
References: <20191121071354.456618-1-jhubbard@nvidia.com>
 <20191121071354.456618-9-jhubbard@nvidia.com>
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To: John Hubbard <jhubbard@nvidia.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Al Viro <viro@zeniv.linux.org.uk>, Alex Williamson <alex.williamson@redhat.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= <bjorn.topel@intel.com>, Christoph Hellwig <hch@infradead.org>, Dan Williams <dan.j.williams@intel.com>, Daniel Vetter <daniel@ffwll.ch>, Dave Chinner <david@fromorbit.com>, David Airlie <airlied@linux.ie>, "David S . Miller" <davem@davemloft.net>, Ira Weiny <ira.weiny@intel.com>, Jan Kara <jack@suse.cz>, Jason Gunthorpe <jgg@ziepe.ca>, Jens Axboe <axboe@kernel.dk>, Jonathan Corbet <corbet@lwn.net>, =?iso-8859-1?B?Suly9G1l?= Glisse <jglisse@redhat.com>, Magnus Karlsson <magnus.karlsson@intel.com>, Mauro Carvalho Chehab <mchehab@kernel.org>, Micha
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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@lst.de>