By default tegra_channel_get_remote_csi_subdev returns next device in pipe
assuming it is CSI but in case of Tegra20 and Tegra30 it can also be VIP
or even HOST. Lets check if returned device is actually CSI by comparing
subdevice operations.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
---
 drivers/staging/media/tegra-video/csi.c | 16 ++++++++++++++++
 drivers/staging/media/tegra-video/vi.c  | 12 ------------
 2 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/media/tegra-video/csi.c b/drivers/staging/media/tegra-video/csi.c
index 3d1d5e1615c2..c848e4ab51ac 100644
--- a/drivers/staging/media/tegra-video/csi.c
+++ b/drivers/staging/media/tegra-video/csi.c
@@ -445,6 +445,22 @@ static const struct v4l2_subdev_ops tegra_csi_ops = {
 	.pad    = &tegra_csi_pad_ops,
 };
 
+struct v4l2_subdev *tegra_channel_get_remote_csi_subdev(struct tegra_vi_channel *chan)
+{
+	struct media_pad *pad;
+	struct v4l2_subdev *subdev;
+
+	pad = media_pad_remote_pad_first(&chan->pad);
+	if (!pad)
+		return NULL;
+
+	subdev = media_entity_to_v4l2_subdev(pad->entity);
+	if (!subdev)
+		return NULL;
+
+	return subdev->ops == &tegra_csi_ops ? subdev : NULL;
+}
+
 static int tegra_csi_channel_alloc(struct tegra_csi *csi,
 				   struct device_node *node,
 				   unsigned int port_num, unsigned int lanes,
diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index 90473729b546..2deb615547be 100644
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -160,18 +160,6 @@ static void tegra_channel_buffer_queue(struct vb2_buffer *vb)
 	wake_up_interruptible(&chan->start_wait);
 }
 
-struct v4l2_subdev *
-tegra_channel_get_remote_csi_subdev(struct tegra_vi_channel *chan)
-{
-	struct media_pad *pad;
-
-	pad = media_pad_remote_pad_first(&chan->pad);
-	if (!pad)
-		return NULL;
-
-	return media_entity_to_v4l2_subdev(pad->entity);
-}
-
 /*
  * Walk up the chain until the initial source (e.g. image sensor)
  */
-- 
2.48.1