[PATCH v6 17/28] media: v4l: subdev: Return routes set using S_ROUTING

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Return the routes set using S_ROUTING back to the user. Also reflect this
in documentation.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 .../userspace-api/media/v4l/vidioc-subdev-g-routing.rst      | 5 +++--
 drivers/media/v4l2-core/v4l2-subdev.c                        | 5 ++++-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
index 9a9765ddc316..ced53ea5f23c 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst
@@ -43,8 +43,9 @@ The routing configuration determines the flows of data inside an entity.
 Drivers report their current routing tables using the
 ``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes
 with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and
-setting or clearing flags of the  ``flags`` field of a
-struct :c:type:`v4l2_subdev_route`.
+setting or clearing flags of the ``flags`` field of a struct
+:c:type:`v4l2_subdev_route`. Similarly to ``VIDIOC_SUBDEV_G_ROUTING``, also
+``VIDIOC_SUBDEV_S_ROUTING`` returns the routes back to the user.
 
 All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is
 called. This means that the userspace must reconfigure all streams after calling
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index bd1e8205913c..9a34e13dfd96 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -935,9 +935,12 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
 		krouting.len_routes = routing->len_routes;
 		krouting.routes = routes;
 
-		return v4l2_subdev_call(sd, pad, set_routing, state,
+		rval = v4l2_subdev_call(sd, pad, set_routing, state,
 					routing->which, &krouting);
+		if (rval < 0)
+			return rval;
 	}
+		fallthrough;
 
 	case VIDIOC_SUBDEV_G_ROUTING: {
 		struct v4l2_subdev_routing *routing = arg;
-- 
2.39.2