diff mbox series

videobuf2-core.h: improve buf_struct_size documentation

Message ID 80c089d1-0902-c780-e941-2fca9915cd07@xs4all.nl (mailing list archive)
State New, archived
Headers show
Series videobuf2-core.h: improve buf_struct_size documentation | expand

Commit Message

Hans Verkuil Feb. 20, 2020, 9:34 a.m. UTC 
Explicitly document that the driver-specific buffer structure
must start with the subsystem-specific struct (vb2_v4l2_buffer
in the case of V4L2).

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
---
diff mbox series

Patch

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a2b2208b02da..f11b96514cf7 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -509,8 +509,11 @@  struct vb2_buf_ops {
  *		by the vb2 core.
  * @buf_struct_size: size of the driver-specific buffer structure;
  *		"0" indicates the driver doesn't want to use a custom buffer
- *		structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
- *		will be used for v4l2.
+ *		structure type. In that case a subsystem-specific struct
+ *		will be used (in the case of V4L2 that is
+ *		``sizeof(struct vb2_v4l2_buffer)``). The first field of the
+ *		driver-specific buffer structure must be the subsystem-specific
+ *		struct (vb2_v4l2_buffer in the case of V4L2).
  * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
  *		``V4L2_BUF_FLAG_TSTAMP_SRC_*``
  * @gfp_flags:	additional gfp flags used when allocating the buffers.