media: v4l2-mem2mem.c: fix broken links

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>

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 1afd9c6ad90848d78c3969f9ce1ad0063858062e..cc34c5ab70099b13968d9c1806fcc29c26ca4993 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -880,12 +880,12 @@ int v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,
                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;