Re: [PATCHv17 24/34] videobuf2-v4l2: integrate with media requests

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

Em Sat,  4 Aug 2018 14:45:16 +0200
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> This implements the V4L2 part of the request support. The main
> change is that vb2_qbuf and vb2_prepare_buf now have a new
> media_device pointer. This required changes to several drivers
> that did not use the vb2_ioctl_qbuf/prepare_buf helper functions.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

> ---
>  .../media/common/videobuf2/videobuf2-core.c   |  13 +-
>  .../media/common/videobuf2/videobuf2-v4l2.c   | 112 ++++++++++++++++--
>  drivers/media/platform/omap3isp/ispvideo.c    |   2 +-
>  .../media/platform/s3c-camif/camif-capture.c  |   4 +-
>  drivers/media/platform/s5p-mfc/s5p_mfc_dec.c  |   4 +-
>  drivers/media/platform/s5p-mfc/s5p_mfc_enc.c  |   4 +-
>  .../media/platform/soc_camera/soc_camera.c    |   4 +-
>  drivers/media/usb/uvc/uvc_queue.c             |   5 +-
>  drivers/media/usb/uvc/uvc_v4l2.c              |   3 +-
>  drivers/media/usb/uvc/uvcvideo.h              |   1 +
>  drivers/media/v4l2-core/v4l2-mem2mem.c        |   6 +-
>  .../staging/media/davinci_vpfe/vpfe_video.c   |   3 +-
>  drivers/staging/media/omap4iss/iss_video.c    |   3 +-
>  drivers/usb/gadget/function/uvc_queue.c       |   2 +-
>  include/media/videobuf2-v4l2.h                |  14 ++-
>  15 files changed, 148 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 1efb9c8b359d..3e6db7d30989 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -1338,6 +1338,14 @@ static void vb2_req_queue(struct media_request_object *obj)
>  	mutex_unlock(vb->vb2_queue->lock);
>  }
>  
> +static void vb2_req_unbind(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)
> +		call_void_bufop(vb->vb2_queue, init_buffer, vb);
> +}
> +
>  static void vb2_req_release(struct media_request_object *obj)
>  {
>  	struct vb2_buffer *vb = container_of(obj, struct vb2_buffer, req_obj);
> @@ -1350,6 +1358,7 @@ static const struct media_request_object_ops vb2_core_req_ops = {
>  	.prepare = vb2_req_prepare,
>  	.unprepare = vb2_req_unprepare,
>  	.queue = vb2_req_queue,
> +	.unbind = vb2_req_unbind,
>  	.release = vb2_req_release,
>  };
>  
> @@ -1481,8 +1490,10 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb,
>  
>  		vb->state = VB2_BUF_STATE_IN_REQUEST;
>  		/* Fill buffer information for the userspace */
> -		if (pb)
> +		if (pb) {
> +			call_void_bufop(q, copy_timestamp, vb, pb);
>  			call_void_bufop(q, fill_user_buffer, vb, pb);
> +		}
>  
>  		dprintk(2, "qbuf of buffer %d succeeded\n", vb->index);
>  		return 0;
> diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> index ea9db4b3f59a..9c652afa62ab 100644
> --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
> +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
> @@ -25,6 +25,7 @@
>  #include <linux/kthread.h>
>  
>  #include <media/v4l2-dev.h>
> +#include <media/v4l2-device.h>
>  #include <media/v4l2-fh.h>
>  #include <media/v4l2-event.h>
>  #include <media/v4l2-common.h>
> @@ -40,10 +41,12 @@ module_param(debug, int, 0644);
>  			pr_info("vb2-v4l2: %s: " fmt, __func__, ## arg); \
>  	} while (0)
>  
> -/* Flags that are set by the vb2 core */
> +/* Flags that are set by us */
>  #define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
>  				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
>  				 V4L2_BUF_FLAG_PREPARED | \
> +				 V4L2_BUF_FLAG_IN_REQUEST | \
> +				 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 | \
> @@ -118,6 +121,16 @@ static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
>  	return 0;
>  }
>  
> +/*
> + * __init_v4l2_vb2_buffer() - initialize the v4l2_vb2_buffer struct
> + */
> +static void __init_v4l2_vb2_buffer(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +
> +	vbuf->request_fd = -1;
> +}
> +
>  static void __copy_timestamp(struct vb2_buffer *vb, const void *pb)
>  {
>  	const struct v4l2_buffer *b = pb;
> @@ -181,6 +194,7 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
>  		return -EINVAL;
>  	}
>  	vbuf->sequence = 0;
> +	vbuf->request_fd = -1;
>  
>  	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
>  		switch (b->memory) {
> @@ -318,9 +332,12 @@ static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b
>  	return 0;
>  }
>  
> -static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
> -				    const char *opname)
> +static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> +				    struct v4l2_buffer *b,
> +				    const char *opname,
> +				    struct media_request **p_req)
>  {
> +	struct media_request *req;
>  	struct vb2_v4l2_buffer *vbuf;
>  	struct vb2_buffer *vb;
>  	int ret;
> @@ -357,8 +374,60 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
>  		memset(vbuf->planes, 0,
>  		       sizeof(vbuf->planes[0]) * vb->num_planes);
>  		ret = vb2_fill_vb2_v4l2_buffer(vb, b);
> +		if (ret)
> +			return ret;
>  	}
> -	return ret;
> +
> +	if (!(b->flags & V4L2_BUF_FLAG_REQUEST_FD))
> +		return 0;
> +
> +	/*
> +	 * For proper locking when queueing a request you need to be able
> +	 * to lock access to the vb2 queue, so check that there is a lock
> +	 * that we can use. In addition p_req must be non-NULL.
> +	 */
> +	if (WARN_ON(!q->lock || !p_req))
> +		return -EINVAL;
> +
> +	/*
> +	 * Make sure this op is implemented by the driver. It's easy to forget
> +	 * this callback, but is it important when canceling a buffer in a
> +	 * queued request.
> +	 */
> +	if (WARN_ON(!q->ops->buf_request_complete))
> +		return -EINVAL;
> +
> +	if (vb->state != VB2_BUF_STATE_DEQUEUED) {
> +		dprintk(1, "%s: buffer is not in dequeued state\n", opname);
> +		return -EINVAL;
> +	}
> +
> +	if (b->request_fd < 0) {
> +		dprintk(1, "%s: request_fd < 0\n", opname);
> +		return -EINVAL;
> +	}
> +
> +	req = media_request_get_by_fd(mdev, b->request_fd);
> +	if (IS_ERR(req)) {
> +		dprintk(1, "%s: invalid request_fd\n", opname);
> +		return PTR_ERR(req);
> +	}
> +
> +	/*
> +	 * Early sanity check. This is checked again when the buffer
> +	 * is bound to the request in vb2_core_qbuf().
> +	 */
> +	if (req->state != MEDIA_REQUEST_STATE_IDLE &&
> +	    req->state != MEDIA_REQUEST_STATE_UPDATING) {
> +		dprintk(1, "%s: request is not idle\n", opname);
> +		media_request_put(req);
> +		return -EBUSY;
> +	}
> +
> +	*p_req = req;
> +	vbuf->request_fd = b->request_fd;
> +
> +	return 0;
>  }
>  
>  /*
> @@ -442,6 +511,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
>  		b->flags |= V4L2_BUF_FLAG_QUEUED;
>  		break;
>  	case VB2_BUF_STATE_IN_REQUEST:
> +		b->flags |= V4L2_BUF_FLAG_IN_REQUEST;
>  		break;
>  	case VB2_BUF_STATE_ERROR:
>  		b->flags |= V4L2_BUF_FLAG_ERROR;
> @@ -456,11 +526,17 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
>  		break;
>  	}
>  
> -	if (vb->state == VB2_BUF_STATE_DEQUEUED && vb->synced && vb->prepared)
> +	if ((vb->state == VB2_BUF_STATE_DEQUEUED ||
> +	     vb->state == VB2_BUF_STATE_IN_REQUEST) &&
> +	    vb->synced && vb->prepared)
>  		b->flags |= V4L2_BUF_FLAG_PREPARED;
>  
>  	if (vb2_buffer_in_use(q, vb))
>  		b->flags |= V4L2_BUF_FLAG_MAPPED;
> +	if (vbuf->request_fd >= 0) {
> +		b->flags |= V4L2_BUF_FLAG_REQUEST_FD;
> +		b->request_fd = vbuf->request_fd;
> +	}
>  
>  	if (!q->is_output &&
>  		b->flags & V4L2_BUF_FLAG_DONE &&
> @@ -494,6 +570,7 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
>  
>  static const struct vb2_buf_ops v4l2_buf_ops = {
>  	.verify_planes_array	= __verify_planes_array_core,
> +	.init_buffer		= __init_v4l2_vb2_buffer,
>  	.fill_user_buffer	= __fill_v4l2_buffer,
>  	.fill_vb2_buffer	= __fill_vb2_buffer,
>  	.copy_timestamp		= __copy_timestamp,
> @@ -542,7 +619,8 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
>  }
>  EXPORT_SYMBOL_GPL(vb2_reqbufs);
>  
> -int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
> +int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> +		    struct v4l2_buffer *b)
>  {
>  	int ret;
>  
> @@ -551,7 +629,10 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
>  		return -EBUSY;
>  	}
>  
> -	ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
> +	if (b->flags & V4L2_BUF_FLAG_REQUEST_FD)
> +		return -EINVAL;
> +
> +	ret = vb2_queue_or_prepare_buf(q, mdev, b, "prepare_buf", NULL);
>  
>  	return ret ? ret : vb2_core_prepare_buf(q, b->index, b);
>  }
> @@ -611,8 +692,10 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
>  }
>  EXPORT_SYMBOL_GPL(vb2_create_bufs);
>  
> -int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
> +int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
> +	     struct v4l2_buffer *b)
>  {
> +	struct media_request *req = NULL;
>  	int ret;
>  
>  	if (vb2_fileio_is_active(q)) {
> @@ -620,8 +703,13 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
>  		return -EBUSY;
>  	}
>  
> -	ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
> -	return ret ? ret : vb2_core_qbuf(q, b->index, b, NULL);
> +	ret = vb2_queue_or_prepare_buf(q, mdev, b, "qbuf", &req);
> +	if (ret)
> +		return ret;
> +	ret = vb2_core_qbuf(q, b->index, b, req);
> +	if (req)
> +		media_request_put(req);
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(vb2_qbuf);
>  
> @@ -811,7 +899,7 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv,
>  
>  	if (vb2_queue_is_busy(vdev, file))
>  		return -EBUSY;
> -	return vb2_prepare_buf(vdev->queue, p);
> +	return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
>  }
>  EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
>  
> @@ -830,7 +918,7 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
>  
>  	if (vb2_queue_is_busy(vdev, file))
>  		return -EBUSY;
> -	return vb2_qbuf(vdev->queue, p);
> +	return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
>  }
>  EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
>  
> diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
> index 674e7fd3ad99..1de7b6b13f67 100644
> --- a/drivers/media/platform/omap3isp/ispvideo.c
> +++ b/drivers/media/platform/omap3isp/ispvideo.c
> @@ -940,7 +940,7 @@ isp_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
>  	int ret;
>  
>  	mutex_lock(&video->queue_lock);
> -	ret = vb2_qbuf(&vfh->queue, b);
> +	ret = vb2_qbuf(&vfh->queue, video->video.v4l2_dev->mdev, b);
>  	mutex_unlock(&video->queue_lock);
>  
>  	return ret;
> diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
> index b1d9f3857d3d..60b62ec6e9cd 100644
> --- a/drivers/media/platform/s3c-camif/camif-capture.c
> +++ b/drivers/media/platform/s3c-camif/camif-capture.c
> @@ -943,7 +943,7 @@ static int s3c_camif_qbuf(struct file *file, void *priv,
>  	if (vp->owner && vp->owner != priv)
>  		return -EBUSY;
>  
> -	return vb2_qbuf(&vp->vb_queue, buf);
> +	return vb2_qbuf(&vp->vb_queue, vp->vdev.v4l2_dev->mdev, buf);
>  }
>  
>  static int s3c_camif_dqbuf(struct file *file, void *priv,
> @@ -981,7 +981,7 @@ static int s3c_camif_prepare_buf(struct file *file, void *priv,
>  				 struct v4l2_buffer *b)
>  {
>  	struct camif_vp *vp = video_drvdata(file);
> -	return vb2_prepare_buf(&vp->vb_queue, b);
> +	return vb2_prepare_buf(&vp->vb_queue, vp->vdev.v4l2_dev->mdev, b);
>  }
>  
>  static int s3c_camif_g_selection(struct file *file, void *priv,
> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
> index 6a3cc4f86c5d..fc0b61f1b91d 100644
> --- a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
> @@ -632,9 +632,9 @@ static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
>  		return -EIO;
>  	}
>  	if (buf->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
> -		return vb2_qbuf(&ctx->vq_src, buf);
> +		return vb2_qbuf(&ctx->vq_src, NULL, buf);
>  	else if (buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> -		return vb2_qbuf(&ctx->vq_dst, buf);
> +		return vb2_qbuf(&ctx->vq_dst, NULL, buf);
>  	return -EINVAL;
>  }
>  
> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> index 3ad4f5073002..9208c83aa377 100644
> --- a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
> @@ -1621,9 +1621,9 @@ static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
>  			mfc_err("Call on QBUF after EOS command\n");
>  			return -EIO;
>  		}
> -		return vb2_qbuf(&ctx->vq_src, buf);
> +		return vb2_qbuf(&ctx->vq_src, NULL, buf);
>  	} else if (buf->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
> -		return vb2_qbuf(&ctx->vq_dst, buf);
> +		return vb2_qbuf(&ctx->vq_dst, NULL, buf);
>  	}
>  	return -EINVAL;
>  }
> diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
> index 901c07f49351..4572fea38d0b 100644
> --- a/drivers/media/platform/soc_camera/soc_camera.c
> +++ b/drivers/media/platform/soc_camera/soc_camera.c
> @@ -394,7 +394,7 @@ static int soc_camera_qbuf(struct file *file, void *priv,
>  	if (icd->streamer != file)
>  		return -EBUSY;
>  
> -	return vb2_qbuf(&icd->vb2_vidq, p);
> +	return vb2_qbuf(&icd->vb2_vidq, NULL, p);
>  }
>  
>  static int soc_camera_dqbuf(struct file *file, void *priv,
> @@ -430,7 +430,7 @@ static int soc_camera_prepare_buf(struct file *file, void *priv,
>  {
>  	struct soc_camera_device *icd = file->private_data;
>  
> -	return vb2_prepare_buf(&icd->vb2_vidq, b);
> +	return vb2_prepare_buf(&icd->vb2_vidq, NULL, b);
>  }
>  
>  static int soc_camera_expbuf(struct file *file, void *priv,
> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
> index fecccb5e7628..8964e16f2b22 100644
> --- a/drivers/media/usb/uvc/uvc_queue.c
> +++ b/drivers/media/usb/uvc/uvc_queue.c
> @@ -300,12 +300,13 @@ int uvc_create_buffers(struct uvc_video_queue *queue,
>  	return ret;
>  }
>  
> -int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
> +int uvc_queue_buffer(struct uvc_video_queue *queue,
> +		     struct media_device *mdev, struct v4l2_buffer *buf)
>  {
>  	int ret;
>  
>  	mutex_lock(&queue->mutex);
> -	ret = vb2_qbuf(&queue->queue, buf);
> +	ret = vb2_qbuf(&queue->queue, mdev, buf);
>  	mutex_unlock(&queue->mutex);
>  
>  	return ret;
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 18a7384b50ee..0a2b8ea8a4ff 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -751,7 +751,8 @@ static int uvc_ioctl_qbuf(struct file *file, void *fh, struct v4l2_buffer *buf)
>  	if (!uvc_has_privileges(handle))
>  		return -EBUSY;
>  
> -	return uvc_queue_buffer(&stream->queue, buf);
> +	return uvc_queue_buffer(&stream->queue,
> +				stream->vdev.v4l2_dev->mdev, buf);
>  }
>  
>  static int uvc_ioctl_expbuf(struct file *file, void *fh,
> diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> index e5f5d84f1d1d..8b7bb89f12df 100644
> --- a/drivers/media/usb/uvc/uvcvideo.h
> +++ b/drivers/media/usb/uvc/uvcvideo.h
> @@ -694,6 +694,7 @@ int uvc_query_buffer(struct uvc_video_queue *queue,
>  int uvc_create_buffers(struct uvc_video_queue *queue,
>  		       struct v4l2_create_buffers *v4l2_cb);
>  int uvc_queue_buffer(struct uvc_video_queue *queue,
> +		     struct media_device *mdev,
>  		     struct v4l2_buffer *v4l2_buf);
>  int uvc_export_buffer(struct uvc_video_queue *queue,
>  		      struct v4l2_exportbuffer *exp);
> diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
> index 0a93c5b173c2..b09494174eb4 100644
> --- a/drivers/media/v4l2-core/v4l2-mem2mem.c
> +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
> @@ -455,11 +455,12 @@ EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
>  int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
>  		  struct v4l2_buffer *buf)
>  {
> +	struct video_device *vdev = video_devdata(file);
>  	struct vb2_queue *vq;
>  	int ret;
>  
>  	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
> -	ret = vb2_qbuf(vq, buf);
> +	ret = vb2_qbuf(vq, vdev->v4l2_dev->mdev, buf);
>  	if (!ret)
>  		v4l2_m2m_try_schedule(m2m_ctx);
>  
> @@ -480,11 +481,12 @@ EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
>  int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
>  			 struct v4l2_buffer *buf)
>  {
> +	struct video_device *vdev = video_devdata(file);
>  	struct vb2_queue *vq;
>  	int ret;
>  
>  	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
> -	ret = vb2_prepare_buf(vq, buf);
> +	ret = vb2_prepare_buf(vq, vdev->v4l2_dev->mdev, buf);
>  	if (!ret)
>  		v4l2_m2m_try_schedule(m2m_ctx);
>  
> diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
> index 4e3ec7fdc90d..6d693067a251 100644
> --- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
> +++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
> @@ -1425,7 +1425,8 @@ static int vpfe_qbuf(struct file *file, void *priv,
>  		return -EACCES;
>  	}
>  
> -	return vb2_qbuf(&video->buffer_queue, p);
> +	return vb2_qbuf(&video->buffer_queue,
> +			video->video_dev.v4l2_dev->mdev, p);
>  }
>  
>  /*
> diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
> index a3a83424a926..a35d1004b522 100644
> --- a/drivers/staging/media/omap4iss/iss_video.c
> +++ b/drivers/staging/media/omap4iss/iss_video.c
> @@ -805,9 +805,10 @@ iss_video_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
>  static int
>  iss_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
>  {
> +	struct iss_video *video = video_drvdata(file);
>  	struct iss_video_fh *vfh = to_iss_video_fh(fh);
>  
> -	return vb2_qbuf(&vfh->queue, b);
> +	return vb2_qbuf(&vfh->queue, video->video.v4l2_dev->mdev, b);
>  }
>  
>  static int
> diff --git a/drivers/usb/gadget/function/uvc_queue.c b/drivers/usb/gadget/function/uvc_queue.c
> index 9e33d5206d54..f2497cb96abb 100644
> --- a/drivers/usb/gadget/function/uvc_queue.c
> +++ b/drivers/usb/gadget/function/uvc_queue.c
> @@ -166,7 +166,7 @@ int uvcg_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf)
>  	unsigned long flags;
>  	int ret;
>  
> -	ret = vb2_qbuf(&queue->queue, buf);
> +	ret = vb2_qbuf(&queue->queue, NULL, buf);
>  	if (ret < 0)
>  		return ret;
>  
> diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
> index 097bf3e6951d..91a2b3e1a642 100644
> --- a/include/media/videobuf2-v4l2.h
> +++ b/include/media/videobuf2-v4l2.h
> @@ -32,6 +32,7 @@
>   *		&enum v4l2_field.
>   * @timecode:	frame timecode.
>   * @sequence:	sequence count of this frame.
> + * @request_fd:	the request_fd associated with this buffer
>   * @planes:	plane information (userptr/fd, length, bytesused, data_offset).
>   *
>   * Should contain enough information to be able to cover all the fields
> @@ -44,6 +45,7 @@ struct vb2_v4l2_buffer {
>  	__u32			field;
>  	struct v4l2_timecode	timecode;
>  	__u32			sequence;
> +	__s32			request_fd;
>  	struct vb2_plane	planes[VB2_MAX_PLANES];
>  };
>  
> @@ -79,6 +81,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
>   * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
>   *
>   * @q:		pointer to &struct vb2_queue with videobuf2 queue.
> + * @mdev:	pointer to &struct media_device, may be NULL.
>   * @b:		buffer structure passed from userspace to
>   *		&v4l2_ioctl_ops->vidioc_prepare_buf handler in driver
>   *
> @@ -90,15 +93,19 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
>   * #) verifies the passed buffer,
>   * #) calls &vb2_ops->buf_prepare callback in the driver (if provided),
>   *    in which driver-specific buffer initialization can be performed.
> + * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
> + *    then bind the prepared buffer to the request.
>   *
>   * The return values from this function are intended to be directly returned
>   * from &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
>   */
> -int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
> +int vb2_prepare_buf(struct vb2_queue *q, struct media_device *mdev,
> +		    struct v4l2_buffer *b);
>  
>  /**
>   * vb2_qbuf() - Queue a buffer from userspace
>   * @q:		pointer to &struct vb2_queue with videobuf2 queue.
> + * @mdev:	pointer to &struct media_device, may be NULL.
>   * @b:		buffer structure passed from userspace to
>   *		&v4l2_ioctl_ops->vidioc_qbuf handler in driver
>   *
> @@ -107,6 +114,8 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
>   * This function:
>   *
>   * #) verifies the passed buffer;
> + * #) if @b->request_fd is non-zero and @mdev->ops->req_queue is set,
> + *    then bind the buffer to the request.
>   * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
>   *    (if provided), in which driver-specific buffer initialization can
>   *    be performed;
> @@ -116,7 +125,8 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
>   * The return values from this function are intended to be directly returned
>   * from &v4l2_ioctl_ops->vidioc_qbuf handler in driver.
>   */
> -int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
> +int vb2_qbuf(struct vb2_queue *q, struct media_device *mdev,
> +	     struct v4l2_buffer *b);
>  
>  /**
>   * vb2_expbuf() - Export a buffer as a file descriptor



Thanks,
Mauro