From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> 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@xxxxxxxxx> Reported-by: Nicolas Dufresne <nicolas@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # for v4.19 and up Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -787,12 +787,12 @@ 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;
