[PATCH v4 5/8] media: docs: uAPI: Clarify error documentation for invalid 'which' value

Laurent Pinchart
2023-12-08T18:16:52Z

Invalid values for the 'which' field of structures passed to multiple
subdev ioctls result in an EINVAL error being returned. The
documentation of the corresponding ioctls indicates this with sentences
such as the following:

the ``which`` field references a non-existing format

This is confusing. Clarify the documentation.

Suggested-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
.../userspace-api/media/v4l/vidioc-subdev-g-crop.rst | 7 +++----
.../userspace-api/media/v4l/vidioc-subdev-g-fmt.rst | 5 ++---
.../media/v4l/vidioc-subdev-g-frame-interval.rst | 7 +++----
.../userspace-api/media/v4l/vidioc-subdev-g-selection.rst | 7 +++----
4 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
index 1d267f7e7991..92d933631fda 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst
@@ -118,10 +118,9 @@ EBUSY
``VIDIOC_SUBDEV_S_CROP``

EINVAL
- The struct :c:type:`v4l2_subdev_crop` ``pad``
- references a non-existing pad, the ``which`` field references a
- non-existing format, or cropping is not supported on the given
- subdev pad.
+ The struct :c:type:`v4l2_subdev_crop` ``pad`` references a non-existing pad,
+ the ``which`` field has an unsupported value, or cropping is not supported
+ on the given subdev pad.

EPERM
The ``VIDIOC_SUBDEV_S_CROP`` ioctl has been called on a read-only subdevice
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst
index ed253a1e44b7..4a2b4e4f0152 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-fmt.rst
@@ -140,9 +140,8 @@ EBUSY
fix the problem first. Only returned by ``VIDIOC_SUBDEV_S_FMT``

EINVAL
- The struct :c:type:`v4l2_subdev_format`
- ``pad`` references a non-existing pad, or the ``which`` field
- references a non-existing format.
+ The struct :c:type:`v4l2_subdev_format` ``pad`` references a non-existing
+ pad, or the ``which`` field has an unsupported value.

EPERM
The ``VIDIOC_SUBDEV_S_FMT`` ioctl has been called on a read-only subdevice
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst
index 41e0e2c8ecc3..c8022809ac35 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-frame-interval.rst
@@ -117,10 +117,9 @@ EBUSY
``VIDIOC_SUBDEV_S_FRAME_INTERVAL``

EINVAL
- The struct
- :c:type:`v4l2_subdev_frame_interval`
- ``pad`` references a non-existing pad, the ``which`` field references a
- non-existing frame interval, or the pad doesn't support frame intervals.
+ The struct :c:type:`v4l2_subdev_frame_interval` ``pad`` references a
+ non-existing pad, the ``which`` field has an unsupported value, or the pad
+ doesn't support frame intervals.

EPERM
The ``VIDIOC_SUBDEV_S_FRAME_INTERVAL`` ioctl has been called on a read-only
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst
index 6b629c19168c..19e6c3e9c06d 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-selection.rst
@@ -116,10 +116,9 @@ EBUSY
``VIDIOC_SUBDEV_S_SELECTION``

EINVAL
- The struct :c:type:`v4l2_subdev_selection`
- ``pad`` references a non-existing pad, the ``which`` field
- references a non-existing format, or the selection target is not
- supported on the given subdev pad.
+ The struct :c:type:`v4l2_subdev_selection` ``pad`` references a
+ non-existing pad, the ``which`` field has an unsupported value, or the
+ selection target is not supported on the given subdev pad.

EPERM
The ``VIDIOC_SUBDEV_S_SELECTION`` ioctl has been called on a read-only