From 316e730f1d8bb029fe6cec2468fb2a50424485b3 Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Date: Tue, 4 Feb 2020 19:13:06 +0100
Subject: [PATCH] media: v4l2-mem2mem.c: fix broken links
Git-commit: 316e730f1d8bb029fe6cec2468fb2a50424485b3
Patch-mainline: v5.6-rc5
References: git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

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

diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 1afd9c6ad908..cc34c5ab7009 100644
--- 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;
-- 
2.16.4