Hi Tomi,

On Sun, Jun 06, 2021 at 01:44:54AM +0300, Laurent Pinchart wrote:

On Mon, May 24, 2021 at 01:44:01PM +0300, Tomi Valkeinen wrote:

quoted

Add route flag to indicate that the route is a source route. This means
that the route does not lead anywhere, and the sink_pad and sink_stream
should not be used.

I don't like this much. It's not a route if it doesn't lead anywhere, so
this flag seems like a hack. If we need a way to discover streams on a
source, I'd rather have an explicit operation to do so. Can't the get
frame descriptor operation be used for this ?

If the need is to find out that we're reaching the end of a pipeline
while going through links and routes, I'd rather have a pad flag to
indicate that the pad is an endpoint.

Also, I can't see where this is being used, so maybe we can just drop it
:-)

quoted

A sensor which provides multiple streams should implement get_routing
and use the flag to mark the routes as sources.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 include/uapi/linux/v4l2-subdev.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index 45c01799e2cd..f20491e1f53f 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h

@@ -200,6 +200,13 @@ struct v4l2_subdev_capability {
  */
 #define V4L2_SUBDEV_ROUTE_FL_IMMUTABLE		BIT(1)
 
+/**
+ * Is the route a source endpoint? A source endpoint route doesn't come
+ * from "anywhere", and the sink_pad and sink_stream fields are unused.
+ * Set by the driver.
+ */
+#define V4L2_SUBDEV_ROUTE_FL_SOURCE		BIT(2)
+
 /**
  * struct v4l2_subdev_route - A route inside a subdev
  *

-- 
Regards,

Laurent Pinchart