[PATCH 5.4 091/168] media: v4l2-mem2mem.c: fix broken links

Greg Kroah-Hartman
2020-03-10T13:29:23Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

commit 316e730f1d8bb029fe6cec2468fb2a50424485b3 upstream.

The topology that v4l2_m2m_register_media_controller() creates for a
processing block actually created a source-to-source link and a sink-to-sink
link instead of two source-to-sink links.

Unfortunately v4l2-compliance never checked for such bad links, so this
went unreported for quite some time.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: Nicolas Dufresne <nicolas@ndufresne.ca>
Cc: <stable@vger.kernel.org> # for v4.19 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/media/v4l2-core/v4l2-mem2mem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -809,12 +809,12 @@ int v4l2_m2m_register_media_controller(s
goto err_rel_entity1;

/* Connect the three entities */
- ret = media_create_pad_link(m2m_dev->source, 0, &m2m_dev->proc, 1,
+ ret = media_create_pad_link(m2m_dev->source, 0, &m2m_dev->proc, 0,
MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
if (ret)
goto err_rel_entity2;

- ret = media_create_pad_link(&m2m_dev->proc, 0, &m2m_dev->sink, 0,
+ ret = media_create_pad_link(&m2m_dev->proc, 1, &m2m_dev->sink, 0,
MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
if (ret)
goto err_rm_links0;