Commit 137272cd authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

media: vb2: add V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF 



This patch adds support for the V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF
flag.

It also adds a new V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF
capability.

Drivers should set vb2_queue->subsystem_flags to
VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF to indicate support
for this flag.

Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 4b1d7c27

Documentation/media/uapi/v4l/buffer.rst

+13 −0
Original line number Diff line number Diff line
@@ -607,6 +607,19 @@ Buffer Flags 
	applications shall use this flag for output buffers if the data in

	this buffer has not been created by the CPU but by some

	DMA-capable unit, in which case caches have not been used.

    * .. _`V4L2-BUF-FLAG-M2M-HOLD-CAPTURE-BUF`:



      - ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF``

      - 0x00000200

      - Only valid if ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` is

	set. It is typically used with stateless decoders where multiple

	output buffers each decode to a slice of the decoded frame.

	Applications can set this flag when queueing the output buffer

	to prevent the driver from dequeueing the capture buffer after

	the output buffer has been decoded (i.e. the capture buffer is

	'held'). If the timestamp of this output buffer differs from that

	of the previous output buffer, then that indicates the start of a

	new frame and the previously held capture buffer is dequeued.

    * .. _`V4L2-BUF-FLAG-LAST`:



      - ``V4L2_BUF_FLAG_LAST``

Documentation/media/uapi/v4l/vidioc-reqbufs.rst

+6 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ aborting or finishing any DMA in progress, an implicit 
.. _V4L2-BUF-CAP-SUPPORTS-DMABUF:

.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS:

.. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS:

.. _V4L2-BUF-CAP-SUPPORTS-M2M-HOLD-CAPTURE-BUF:



.. cssclass:: longtable
@@ -150,6 +151,11 @@ aborting or finishing any DMA in progress, an implicit 
      - The kernel allows calling :ref:`VIDIOC_REQBUFS` while buffers are still

        mapped or exported via DMABUF. These orphaned buffers will be freed

        when they are unmapped or when the exported DMABUF fds are closed.

    * - ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF``

      - 0x00000020

      - Only valid for stateless decoders. If set, then userspace can set the

        ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag to hold off on returning the

	capture buffer until the OUTPUT timestamp changes.



Return Value

============

drivers/media/common/videobuf2/videobuf2-v4l2.c

+10 −2
Original line number Diff line number Diff line
@@ -49,8 +49,11 @@ module_param(debug, int, 0644); 
				 V4L2_BUF_FLAG_REQUEST_FD | \

				 V4L2_BUF_FLAG_TIMESTAMP_MASK)

/* Output buffer flags that should be passed on to the driver */

#define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \

				 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)

#define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | \

				 V4L2_BUF_FLAG_BFRAME | \

				 V4L2_BUF_FLAG_KEYFRAME | \

				 V4L2_BUF_FLAG_TIMECODE | \

				 V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF)



/*

 * __verify_planes_array() - verify that the planes array passed in struct
@@ -194,6 +197,7 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b 
	}

	vbuf->sequence = 0;

	vbuf->request_fd = -1;

	vbuf->is_held = false;



	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {

		switch (b->memory) {
@@ -321,6 +325,8 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b 
		 */

		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;

		vbuf->field = b->field;

		if (!(q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF))

			vbuf->flags &= ~V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF;

	} else {

		/* Zero any output buffer flags as this is a capture buffer */

		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
@@ -654,6 +660,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) 
		*caps |= V4L2_BUF_CAP_SUPPORTS_USERPTR;

	if (q->io_modes & VB2_DMABUF)

		*caps |= V4L2_BUF_CAP_SUPPORTS_DMABUF;

	if (q->subsystem_flags & VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF)

		*caps |= V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF;

#ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API

	if (q->supports_requests)

		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;

include/media/videobuf2-core.h

+3 −0
Original line number Diff line number Diff line
@@ -505,6 +505,8 @@ struct vb2_buf_ops { 
 * @buf_ops:	callbacks to deliver buffer information.

 *		between user-space and kernel-space.

 * @drv_priv:	driver private data.

 * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used

 *		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)``
@@ -571,6 +573,7 @@ struct vb2_queue { 
	const struct vb2_buf_ops	*buf_ops;



	void				*drv_priv;

	u32				subsystem_flags;

	unsigned int			buf_struct_size;

	u32				timestamp_flags;

	gfp_t				gfp_flags;

include/media/videobuf2-v4l2.h

+5 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
 * @timecode:	frame timecode.

 * @sequence:	sequence count of this frame.

 * @request_fd:	the request_fd associated with this buffer

 * @is_held:	if true, then this capture buffer was held

 * @planes:	plane information (userptr/fd, length, bytesused, data_offset).

 *

 * Should contain enough information to be able to cover all the fields
@@ -46,9 +47,13 @@ struct vb2_v4l2_buffer { 
	struct v4l2_timecode	timecode;

	__u32			sequence;

	__s32			request_fd;

	bool			is_held;

	struct vb2_plane	planes[VB2_MAX_PLANES];

};



/* VB2 V4L2 flags as set in vb2_queue.subsystem_flags */

#define VB2_V4L2_FL_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 0)



/*

 * to_vb2_v4l2_buffer() - cast struct vb2_buffer * to struct vb2_v4l2_buffer *

 */