diff --git a/Documentation/driver-api/media/v4l2-subdev.rst b/Documentation/driver-api/media/v4l2-subdev.rst index cf3b52bdbfb9..6f8d79926aa5 100644 --- a/Documentation/driver-api/media/v4l2-subdev.rst +++ b/Documentation/driver-api/media/v4l2-subdev.rst @@ -243,6 +243,12 @@ notifier callback is called. After all subdevices have been located the .complete() callback is called. When a subdevice is removed from the system the .unbind() method is called. All three callbacks are optional. +Drivers can store any type of custom data in their driver-specific +:c:type:`v4l2_async_subdev` wrapper. If any of that data requires special +handling when the structure is freed, drivers must implement the ``.destroy()`` +notifier callback. The framework will call it right before freeing the +:c:type:`v4l2_async_subdev`. + Calling subdev operations ~~~~~~~~~~~~~~~~~~~~~~~~~ diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c index b16f3ce8e5ef..2f1b718a9189 100644 --- a/drivers/media/v4l2-core/v4l2-async.c +++ b/drivers/media/v4l2-core/v4l2-async.c @@ -52,6 +52,15 @@ static int v4l2_async_nf_call_complete(struct v4l2_async_notifier *n) return n->ops->complete(n); } +static void v4l2_async_nf_call_destroy(struct v4l2_async_notifier *n, + struct v4l2_async_subdev *asd) +{ + if (!n->ops || !n->ops->destroy) + return; + + n->ops->destroy(asd); +} + static bool match_i2c(struct v4l2_async_notifier *notifier, struct v4l2_subdev *sd, struct v4l2_async_subdev *asd) { @@ -633,6 +642,7 @@ static void __v4l2_async_nf_cleanup(struct v4l2_async_notifier *notifier) } list_del(&asd->asd_list); + v4l2_async_nf_call_destroy(notifier, asd); kfree(asd); } } diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h index 13ff3ad948f4..25eb1d138c06 100644 --- a/include/media/v4l2-async.h +++ b/include/media/v4l2-async.h @@ -81,6 +81,7 @@ struct v4l2_async_subdev { * @complete: All subdevices have been probed successfully. The complete * callback is only executed for the root notifier. * @unbind: a subdevice is leaving + * @destroy: the asd is about to be freed */ struct v4l2_async_notifier_operations { int (*bound)(struct v4l2_async_notifier *notifier, @@ -90,6 +91,7 @@ struct v4l2_async_notifier_operations { void (*unbind)(struct v4l2_async_notifier *notifier, struct v4l2_subdev *subdev, struct v4l2_async_subdev *asd); + void (*destroy)(struct v4l2_async_subdev *asd); }; /**