From 7789d6138711f94af461d1096d64492e333009ed Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 22 Mar 2021 15:44:08 +0100
Subject: media: video-mux: Skip dangling endpoints

From: Philipp Zabel <p.zabel@pengutronix.de>

[ Upstream commit 95778c2d0979618e3349b1d2324ec282a5a6adbf ]

i.MX6 device tree include files contain dangling endpoints for the
board device tree writers' convenience. These are still included in
many existing device trees.
Treat dangling endpoints as non-existent to support them.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: 612b385efb1e ("media: video-mux: Create media links in bound notifier")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/video-mux.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/video-mux.c b/drivers/media/platform/video-mux.c
index 7b280dfca727..640ce76fe0d9 100644
--- a/drivers/media/platform/video-mux.c
+++ b/drivers/media/platform/video-mux.c
@@ -362,7 +362,7 @@ static int video_mux_async_register(struct video_mux *vmux,
 
 	for (i = 0; i < num_input_pads; i++) {
 		struct v4l2_async_subdev *asd;
-		struct fwnode_handle *ep;
+		struct fwnode_handle *ep, *remote_ep;
 
 		ep = fwnode_graph_get_endpoint_by_id(
 			dev_fwnode(vmux->subdev.dev), i, 0,
@@ -370,6 +370,14 @@ static int video_mux_async_register(struct video_mux *vmux,
 		if (!ep)
 			continue;
 
+		/* Skip dangling endpoints for backwards compatibility */
+		remote_ep = fwnode_graph_get_remote_endpoint(ep);
+		if (!remote_ep) {
+			fwnode_handle_put(ep);
+			continue;
+		}
+		fwnode_handle_put(remote_ep);
+
 		asd = v4l2_async_notifier_add_fwnode_remote_subdev(
 			&vmux->notifier, ep, sizeof(*asd));
 
-- 
2.30.2