From: Hans Verkuil <hansverk@xxxxxxxxx>
Mention that IDs should not be hardcoded in applications and that the
entity name must be unique within the media topology.
Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx>
---
.../uapi/mediactl/media-ioc-enum-entities.rst | 9 +++++---
.../uapi/mediactl/media-ioc-g-topology.rst | 22 ++++++++++++++-----
2 files changed, 22 insertions(+), 9 deletions(-)
diff --git a/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst b/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst
index 961466ae821d..a4aa7deef690 100644
--- a/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst
+++ b/Documentation/media/uapi/mediactl/media-ioc-enum-entities.rst
@@ -62,15 +62,18 @@ id's until they get an error.
- ``id``
-
-
- - Entity id, set by the application. When the id is or'ed with
+ - Entity id, set by the application. When the ID is or'ed with
``MEDIA_ENT_ID_FLAG_NEXT``, the driver clears the flag and returns
- the first entity with a larger id.
+ the first entity with a larger ID. Do not expect that the ID will
+ always be the same for each instance of the device. In other words,
+ do not hardcode entity IDs in an application.
* - char
- ``name``\ [32]
-
-
- - Entity name as an UTF-8 NULL-terminated string.
+ - Entity name as an UTF-8 NULL-terminated string. This name must be unique
+ within the media topology.
* - __u32
- ``type``
diff --git a/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst b/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst
index e572dd0d806d..3a5f165d9811 100644
--- a/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst
+++ b/Documentation/media/uapi/mediactl/media-ioc-g-topology.rst
@@ -131,11 +131,14 @@ desired arrays with the media graph elements.
* - __u32
- ``id``
- - Unique ID for the entity.
+ - Unique ID for the entity. Do not expect that the ID will
+ always be the same for each instance of the device. In other words,
+ do not hardcode entity IDs in an application.
* - char
- ``name``\ [64]
- - Entity name as an UTF-8 NULL-terminated string.
+ - Entity name as an UTF-8 NULL-terminated string. This name must be unique
+ within the media topology.
* - __u32
- ``function``
@@ -166,7 +169,9 @@ desired arrays with the media graph elements.
* - __u32
- ``id``
- - Unique ID for the interface.
+ - Unique ID for the interface. Do not expect that the ID will
+ always be the same for each instance of the device. In other words,
+ do not hardcode interface IDs in an application.
* - __u32
- ``intf_type``
@@ -215,7 +220,9 @@ desired arrays with the media graph elements.
* - __u32
- ``id``
- - Unique ID for the pad.
+ - Unique ID for the pad. Do not expect that the ID will
+ always be the same for each instance of the device. In other words,
+ do not hardcode pad IDs in an application.
* - __u32
- ``entity_id``
@@ -231,7 +238,8 @@ desired arrays with the media graph elements.
returns true. The ``media_version`` is defined in struct
:c:type:`media_device_info` and can be retrieved using
:ref:`MEDIA_IOC_DEVICE_INFO`. Pad indices are stable. If new pads are added
- for an entity in the future, then those will be added at the end.
+ for an entity in the future, then those will be added at the end of the
+ entity's pad array.
* - __u32
- ``reserved``\ [4]
@@ -250,7 +258,9 @@ desired arrays with the media graph elements.
* - __u32
- ``id``
- - Unique ID for the link.
+ - Unique ID for the link. Do not expect that the ID will
+ always be the same for each instance of the device. In other words,
+ do not hardcode link IDs in an application.
* - __u32
- ``source_id``
--
2.17.0
