[PATCH v12 20/86] media: Documentation: There are either immutable or mutable routes

Sakari Ailus
2026-04-09T20:15:28Z

Document that each sub-device may have either immutable or mutable routes,
not both of them.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
Documentation/userspace-api/media/v4l/dev-subdev.rst | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst
index 78842b9fbe67..57bd44dbbeea 100644
--- a/Documentation/userspace-api/media/v4l/dev-subdev.rst
+++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst
@@ -616,6 +616,12 @@ and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is
called on the sub-device. Such newly created routes have the device's default
configuration for format and selection rectangles.

+A sub-device may only have either static routes (routes that have
+``V4L2_SUBDEV_ROUTE_FL_STATIC`` flag set) or routes that are all user-created or
+user-removable (routes that do not have ``V4L2_SUBDEV_ROUTE_FL_STATIC``
+flag). Mixing static and non-static routes is not allowed in the same
+sub-device. This is subject to change in the future.
+
Configuring streams
-------------------

--
2.47.3