From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 033/118] media/v4l2-core: set pages dirty upon releasing DMA buffers Date: Thu, 30 Jan 2020 22:12:50 -0800 Message-ID: <20200131061250.z37jD6vNq%akpm@linux-foundation.org> References: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail.kernel.org ([198.145.29.99]:60258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726399AbgAaGMx (ORCPT ); Fri, 31 Jan 2020 01:12:53 -0500 In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, alex.williamson@redhat.com, aneesh.kumar@linux.ibm.com, axboe@kernel.dk, bjorn.topel@intel.com, corbet@lwn.net, dan.j.williams@intel.com, daniel.vetter@ffwll.ch, hch@lst.de, hverkuil-cisco@xs4all.nl, ira.weiny@intel.com, jack@suse.cz, jgg@mellanox.com, jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com, kirill@shutemov.name, leonro@mellanox.com, linux-mm@kvack.org, mchehab@kernel.org, mm-commits@vger.kernel.org, rppt@linux.ibm.com, stable@vger.kernel.org, torvalds@linux-foundation.org =46rom: John Hubbard Subject: media/v4l2-core: set pages dirty upon releasing DMA buffers 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. Link: http://lkml.kernel.org/r/20200107224558.2362728-11-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Christoph Hellwig Acked-by: Hans Verkuil Cc: Mauro Carvalho Chehab Cc: Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Bj=C3=B6rn T=C3=B6pel Cc: Daniel Vetter Cc: Dan Williams Cc: Ira Weiny Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Jerome Glisse Cc: Jonathan Corbet Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mike Rapoport Signed-off-by: Andrew Morton --- drivers/media/v4l2-core/videobuf-dma-sg.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/media/v4l2-core/videobuf-dma-sg.c~media-v4l2-core-set-pages-d= irty-upon-releasing-dma-buffers +++ a/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -349,8 +349,11 @@ int videobuf_dma_free(struct videobuf_dm BUG_ON(dma->sglen); =20 if (dma->pages) { - for (i =3D 0; i < dma->nr_pages; i++) + for (i =3D 0; i < dma->nr_pages; i++) { + if (dma->direction =3D=3D DMA_FROM_DEVICE) + set_page_dirty_lock(dma->pages[i]); put_page(dma->pages[i]); + } kfree(dma->pages); dma->pages =3D NULL; } _