Re: [PATCHv17 23/34] videobuf2-core: integrate with media requests

[Mauro Carvalho Chehab <mchehab+samsung@kernel.org>]

Em Sat,  4 Aug 2018 14:45:15 +0200
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Buffers can now be prepared or queued for a request.
> 
> A buffer is unbound from the request at vb2_buffer_done time or
> when the queue is cancelled.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

> ---
>  .../media/common/videobuf2/videobuf2-core.c   | 133 +++++++++++++++++-
>  .../media/common/videobuf2/videobuf2-v4l2.c   |   4 +-
>  drivers/media/dvb-core/dvb_vb2.c              |   2 +-
>  include/media/videobuf2-core.h                |  18 ++-
>  4 files changed, 147 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 230f83d6d094..1efb9c8b359d 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -499,8 +499,9 @@ static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
>  			pr_info("     buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n",
>  				vb->cnt_buf_init, vb->cnt_buf_cleanup,
>  				vb->cnt_buf_prepare, vb->cnt_buf_finish);
> -			pr_info("     buf_queue: %u buf_done: %u\n",
> -				vb->cnt_buf_queue, vb->cnt_buf_done);
> +			pr_info("     buf_queue: %u buf_done: %u buf_request_complete: %u\n",
> +				vb->cnt_buf_queue, vb->cnt_buf_done,
> +				vb->cnt_buf_request_complete);
>  			pr_info("     alloc: %u put: %u prepare: %u finish: %u mmap: %u\n",
>  				vb->cnt_mem_alloc, vb->cnt_mem_put,
>  				vb->cnt_mem_prepare, vb->cnt_mem_finish,
> @@ -936,6 +937,14 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
>  		vb->state = state;
>  	}
>  	atomic_dec(&q->owned_by_drv_count);
> +
> +	if (vb->req_obj.req) {
> +		/* This is not supported at the moment */
> +		WARN_ON(state == VB2_BUF_STATE_REQUEUEING);
> +		media_request_object_unbind(&vb->req_obj);
> +		media_request_object_put(&vb->req_obj);
> +	}
> +
>  	spin_unlock_irqrestore(&q->done_lock, flags);
>  
>  	trace_vb2_buf_done(q, vb);
> @@ -1290,6 +1299,60 @@ static int __buf_prepare(struct vb2_buffer *vb)
>  	return 0;
>  }
>  
> +static int vb2_req_prepare(struct media_request_object *obj)
> +{
> +	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
> +	int ret;
> +
> +	if (WARN_ON(vb->state != VB2_BUF_STATE_IN_REQUEST))
> +		return -EINVAL;
> +
> +	mutex_lock(vb->vb2_queue->lock);
> +	ret = __buf_prepare(vb);
> +	mutex_unlock(vb->vb2_queue->lock);
> +	return ret;
> +}
> +
> +static void __vb2_dqbuf(struct vb2_buffer *vb);
> +
> +static void vb2_req_unprepare(struct media_request_object *obj)
> +{
> +	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
> +
> +	mutex_lock(vb->vb2_queue->lock);
> +	__vb2_dqbuf(vb);
> +	vb->state = VB2_BUF_STATE_IN_REQUEST;
> +	mutex_unlock(vb->vb2_queue->lock);
> +	WARN_ON(!vb->req_obj.req);
> +}
> +
> +int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> +		  struct media_request *req);
> +
> +static void vb2_req_queue(struct media_request_object *obj)
> +{
> +	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
> +
> +	mutex_lock(vb->vb2_queue->lock);
> +	vb2_core_qbuf(vb->vb2_queue, vb->index, NULL, NULL);
> +	mutex_unlock(vb->vb2_queue->lock);
> +}
> +
> +static void vb2_req_release(struct media_request_object *obj)
> +{
> +	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
> +
> +	if (vb->state == VB2_BUF_STATE_IN_REQUEST)
> +		vb->state = VB2_BUF_STATE_DEQUEUED;

Shouldn't it be protected by the lock?

> +}
> +
> +static const struct media_request_object_ops vb2_core_req_ops = {
> +	.prepare = vb2_req_prepare,
> +	.unprepare = vb2_req_unprepare,
> +	.queue = vb2_req_queue,
> +	.release = vb2_req_release,
> +};
> +
>  int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
>  {
>  	struct vb2_buffer *vb;
> @@ -1315,7 +1378,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
>  
>  	dprintk(2, "prepare of buffer %d succeeded\n", vb->index);
>  
> -	return ret;
> +	return 0;
>  }
>  EXPORT_SYMBOL_GPL(vb2_core_prepare_buf);
>  
> @@ -1382,7 +1445,8 @@ static int vb2_start_streaming(struct vb2_queue *q)
>  	return ret;
>  }
>  
> -int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
> +int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> +		  struct media_request *req)
>  {
>  	struct vb2_buffer *vb;
>  	int ret;
> @@ -1394,8 +1458,39 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
>  
>  	vb = q->bufs[index];
>  
> +	if (req) {
> +		int ret;
> +
> +		if (vb->state != VB2_BUF_STATE_DEQUEUED) {
> +			dprintk(1, "buffer %d not in dequeued state\n",
> +				vb->index);
> +			return -EINVAL;
> +		}
> +
> +		media_request_object_init(&vb->req_obj);
> +
> +		/* Make sure the request is in a safe state for updating. */
> +		ret = media_request_lock_for_update(req);
> +		if (ret)
> +			return ret;
> +		ret = media_request_object_bind(req, &vb2_core_req_ops,
> +						q, &vb->req_obj);
> +		media_request_unlock_for_update(req);
> +		if (ret)
> +			return ret;
> +
> +		vb->state = VB2_BUF_STATE_IN_REQUEST;
> +		/* Fill buffer information for the userspace */
> +		if (pb)
> +			call_void_bufop(q, fill_user_buffer, vb, pb);
> +
> +		dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
> +		return 0;
> +	}
> +
>  	switch (vb->state) {
>  	case VB2_BUF_STATE_DEQUEUED:
> +	case VB2_BUF_STATE_IN_REQUEST:
>  		if (!vb->prepared) {
>  			ret = __buf_prepare(vb);
>  			if (ret)
> @@ -1601,6 +1696,11 @@ static void __vb2_dqbuf(struct vb2_buffer *vb)
>  			call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv);
>  			vb->planes[i].dbuf_mapped = 0;
>  		}
> +	if (vb->req_obj.req) {
> +		media_request_object_unbind(&vb->req_obj);
> +		media_request_object_put(&vb->req_obj);
> +	}
> +	call_void_bufop(q, init_buffer, vb);
>  }
>  
>  int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
> @@ -1714,6 +1814,25 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
>  	 */
>  	for (i = 0; i < q->num_buffers; ++i) {
>  		struct vb2_buffer *vb = q->bufs[i];
> +		struct media_request *req = vb->req_obj.req;
> +
> +		/*
> +		 * If a request is associated with this buffer, then
> +		 * call buf_request_cancel() to give the driver to complete()
> +		 * related request objects. Otherwise those objects would
> +		 * never complete.
> +		 */
> +		if (req) {
> +			enum media_request_state state;
> +			unsigned long flags;
> +
> +			spin_lock_irqsave(&req->lock, flags);
> +			state = req->state;
> +			spin_unlock_irqrestore(&req->lock, flags);
> +
> +			if (state == MEDIA_REQUEST_STATE_QUEUED)
> +				call_void_vb_qop(vb, buf_request_complete, vb);
> +		}
>  
>  		if (vb->synced) {
>  			unsigned int plane;
> @@ -2283,7 +2402,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
>  		 * Queue all buffers.
>  		 */
>  		for (i = 0; i < q->num_buffers; i++) {
> -			ret = vb2_core_qbuf(q, i, NULL);
> +			ret = vb2_core_qbuf(q, i, NULL, NULL);
>  			if (ret)
>  				goto err_reqbufs;
>  			fileio->bufs[i].queued = 1;
> @@ -2462,7 +2581,7 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
>  
>  		if (copy_timestamp)
>  			b->timestamp = ktime_get_ns();
> -		ret = vb2_core_qbuf(q, index, NULL);
> +		ret = vb2_core_qbuf(q, index, NULL, NULL);
>  		dprintk(5, "vb2_dbuf result: %d\n", ret);
>  		if (ret)
>  			return ret;
> @@ -2565,7 +2684,7 @@ static int vb2_thread(void *data)
>  		if (copy_timestamp)
>  			vb->timestamp = ktime_get_ns();
>  		if (!threadio->stop)
> -			ret = vb2_core_qbuf(q, vb->index, NULL);
> +			ret = vb2_core_qbuf(q, vb->index, NULL, NULL);
>  		call_void_qop(q, wait_prepare, q);
>  		if (ret || threadio->stop)
>  			break;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index 64905d87465c..ea9db4b3f59a 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -441,6 +441,8 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
>  	case VB2_BUF_STATE_ACTIVE:
>  		b->flags |= V4L2_BUF_FLAG_QUEUED;
>  		break;
> +	case VB2_BUF_STATE_IN_REQUEST:
> +		break;
>  	case VB2_BUF_STATE_ERROR:
>  		b->flags |= V4L2_BUF_FLAG_ERROR;
>  		/* fall through */
> @@ -619,7 +621,7 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
>  	}
>  
>  	ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
> -	return ret ? ret : vb2_core_qbuf(q, b->index, b);
> +	return ret ? ret : vb2_core_qbuf(q, b->index, b, NULL);
>  }
>  EXPORT_SYMBOL_GPL(vb2_qbuf);
>  
> diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
> index da6a8cec7d42..f1e7f0536028 100644
> --- a/drivers/media/dvb-core/dvb_vb2.c
> +++ b/drivers/media/dvb-core/dvb_vb2.c
> @@ -384,7 +384,7 @@ int dvb_vb2_qbuf(struct dvb_vb2_ctx *ctx, struct dmx_buffer *b)
>  {
>  	int ret;
>  
> -	ret = vb2_core_qbuf(&ctx->vb_q, b->index, b);
> +	ret = vb2_core_qbuf(&ctx->vb_q, b->index, b, NULL);
>  	if (ret) {
>  		dprintk(1, "[%s] index=%d errno=%d\n", ctx->name,
>  			b->index, ret);
> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index df92dcdeabb3..8a8d7732d182 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -204,6 +204,7 @@ enum vb2_io_modes {
>  /**
>   * enum vb2_buffer_state - current video buffer state.
>   * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control.
> + * @VB2_BUF_STATE_IN_REQUEST:	buffer is queued in media request.
>   * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf.
>   * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver.
>   * @VB2_BUF_STATE_REQUEUEING:	re-queue a buffer to the driver.
> @@ -217,6 +218,7 @@ enum vb2_io_modes {
>   */
>  enum vb2_buffer_state {
>  	VB2_BUF_STATE_DEQUEUED,
> +	VB2_BUF_STATE_IN_REQUEST,
>  	VB2_BUF_STATE_PREPARING,
>  	VB2_BUF_STATE_QUEUED,
>  	VB2_BUF_STATE_REQUEUEING,
> @@ -293,6 +295,7 @@ struct vb2_buffer {
>  	u32		cnt_buf_finish;
>  	u32		cnt_buf_cleanup;
>  	u32		cnt_buf_queue;
> +	u32		cnt_buf_request_complete;
>  
>  	/* This counts the number of calls to vb2_buffer_done() */
>  	u32		cnt_buf_done;
> @@ -386,6 +389,11 @@ struct vb2_buffer {
>   *			ioctl; might be called before @start_streaming callback
>   *			if user pre-queued buffers before calling
>   *			VIDIOC_STREAMON().
> + * @buf_request_complete: a buffer that was never queued to the driver but is
> + *			associated with a queued request was canceled.
> + *			The driver will have to mark associated objects in the
> + *			request as completed; required if requests are
> + *			supported.
>   */
>  struct vb2_ops {
>  	int (*queue_setup)(struct vb2_queue *q,
> @@ -404,6 +412,8 @@ struct vb2_ops {
>  	void (*stop_streaming)(struct vb2_queue *q);
>  
>  	void (*buf_queue)(struct vb2_buffer *vb);
> +
> +	void (*buf_request_complete)(struct vb2_buffer *vb);
>  };
>  
>  /**
> @@ -761,12 +771,17 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
>   * @index:	id number of the buffer
>   * @pb:		buffer structure passed from userspace to
>   *		v4l2_ioctl_ops->vidioc_qbuf handler in driver
> + * @req:	pointer to &struct media_request, may be NULL.
>   *
>   * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
>   * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
>   *
>   * This function:
>   *
> + * #) If @req is non-NULL, then the buffer will be bound to this
> + *    media request and it returns. The buffer will be prepared and
> + *    queued to the driver (i.e. the next two steps) when the request
> + *    itself is queued.
>   * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
>   *    (if provided), in which driver-specific buffer initialization can
>   *    be performed;
> @@ -775,7 +790,8 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
>   *
>   * Return: returns zero on success; an error code otherwise.
>   */
> -int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
> +int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
> +		  struct media_request *req);
>  
>  /**
>   * vb2_core_dqbuf() - Dequeue a buffer to the userspace



Thanks,
Mauro