media: Documentation: v4l: Document that link_validate op is valid for sink only

The link_validate pad op will only be called on sink pads. Document this.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
This commit is contained in:
Sakari Ailus 2020-11-30 14:46:06 +01:00 committed by Mauro Carvalho Chehab
parent 352cf679c7
commit 25c8d9a768
1 changed files with 6 additions and 5 deletions

View File

@ -122,11 +122,12 @@ Don't forget to cleanup the media entity before the sub-device is destroyed:
media_entity_cleanup(&sd->entity);
In that case, the subdev driver may set the link_validate field to provide
its own link validation function. The link validation function is called for
every link in the pipeline where both of the ends of the links are V4L2
sub-devices. The driver is still responsible for validating the correctness
of the format configuration between sub-devices and video nodes.
If a sub-device driver implements sink pads, the subdev driver may set the
link_validate field in :c:type:`v4l2_subdev_pad_ops`to provide its own link
validation function. For every link in the pipeline, the link_validate pad
operation of the sink end of the link is called. In both cases the driver is
still responsible for validating the correctness of the format configuration
between sub-devices and video nodes.
If link_validate op is not set, the default function
:c:func:`v4l2_subdev_link_validate_default` is used instead. This function