From 6a6e49f89297cdf2c8c4deec54395179643b4a05 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 1 Nov 2023 10:00:05 +0200 Subject: media: Documentation: Initialisation finishes before subdev registration Document that sub-device initialisation needs to complete before the async sub-device is registered as there is no further driver action needed before the sensor becomes accessible via the UAPI. Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil --- Documentation/driver-api/media/v4l2-subdev.rst | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/driver-api/media/v4l2-subdev.rst') diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst index a62e4aff31be..1db2ba27c54c 100644 --- a/Documentation/driver-api/media/v4l2-subdev.rst +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -181,6 +181,8 @@ You can unregister a sub-device using: Afterwards the subdev module can be unloaded and :c:type:`sd `->dev == ``NULL``. +.. _media-registering-async-subdevs: + Registering asynchronous sub-devices ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -195,6 +197,11 @@ performed using the :c:func:`v4l2_async_unregister_subdev` call. Subdevices registered this way are stored in a global list of subdevices, ready to be picked up by bridge drivers. +Drivers must complete all initialization of the sub-device before +registering it using :c:func:`v4l2_async_register_subdev`, including +enabling runtime PM. This is because the sub-device becomes accessible +as soon as it gets registered. + Asynchronous sub-device notifiers ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ -- cgit v1.2.3