Re: [RFCv1 PATCH 3/6] videobuf2-core: move plane verification out of __fill_v4l2_buffer.

[Sylwester Nawrocki <s.nawrocki@samsung.com>]

On 09/19/2012 04:37 PM, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> The plane verification should be done before actually queuing or
> dequeuing buffers, so move it out of __fill_v4l2_buffer and call it
> as a separate step.
> 
> The also makes it possible to change the return type of __fill_v4l2_buffer
> to void.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

There are just two small comment below...

> ---
>  drivers/media/v4l2-core/videobuf2-core.c |   29 +++++++++++++++++------------
>  1 file changed, 17 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
> index 2e26e58..929cc99 100644
> --- a/drivers/media/v4l2-core/videobuf2-core.c
> +++ b/drivers/media/v4l2-core/videobuf2-core.c
> @@ -276,6 +276,9 @@ static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
>   */
>  static int __verify_planes_array(struct vb2_queue *q, const struct v4l2_buffer *b)
>  {
> +	if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
> +		return 0;
> +
>  	/* Is memory for copying plane information present? */
>  	if (NULL == b->m.planes) {
>  		dprintk(1, "Multi-planar buffer passed but "
> @@ -331,10 +334,9 @@ static bool __buffers_in_use(struct vb2_queue *q)
>   * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
>   * returned to userspace
>   */
> -static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
> +static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
>  {
>  	struct vb2_queue *q = vb->vb2_queue;
> -	int ret;
>  
>  	/* Copy back data such as timestamp, flags, etc. */
>  	memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
> @@ -342,10 +344,6 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
>  	b->reserved = vb->v4l2_buf.reserved;
>  
>  	if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
> -		ret = __verify_planes_array(q, b);
> -		if (ret)
> -			return ret;
> -
>  		/*
>  		 * Fill in plane-related data if userspace provided an array
>  		 * for it. The memory and size is verified above.

This comment should be updated, since __verify_planes_array() is now removed.

> @@ -391,8 +389,6 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
>  
>  	if (__buffer_in_use(q, vb))
>  		b->flags |= V4L2_BUF_FLAG_MAPPED;
> -
> -	return 0;
>  }
>  
>  /**
> @@ -411,6 +407,7 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
>  int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
>  {
>  	struct vb2_buffer *vb;
> +	int ret;
>  
>  	if (b->type != q->type) {
>  		dprintk(1, "querybuf: wrong buffer type\n");
> @@ -422,8 +419,10 @@ int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
>  		return -EINVAL;
>  	}
>  	vb = q->bufs[b->index];
> -
> -	return __fill_v4l2_buffer(vb, b);
> +	ret = __verify_planes_array(q, b);
> +	if (!ret)
> +		__fill_v4l2_buffer(vb, b);
> +	return ret;
>  }
>  EXPORT_SYMBOL(vb2_querybuf);
>  
> @@ -1061,8 +1060,8 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
>  		dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state);
>  		return -EINVAL;
>  	}
> -
> -	ret = __buf_prepare(vb, b);
> +	ret = __verify_planes_array(q, b);
> +	ret = ret ? ret : __buf_prepare(vb, b);

Could we just make it:

	ret = __verify_planes_array(q, b);
  	if (ret < 0)
  		return ret;

	ret = __buf_prepare(vb, b);
  	if (ret < 0)
  		return ret;

?
>  	if (ret < 0)
>  		return ret;
>  
> @@ -1149,6 +1148,9 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
>  		ret = -EINVAL;
>  		goto unlock;
>  	}
> +	ret = __verify_planes_array(q, b);
> +	if (ret)
> +		return ret;
>  
>  	switch (vb->state) {
>  	case VB2_BUF_STATE_DEQUEUED:
> @@ -1337,6 +1339,9 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
>  		dprintk(1, "dqbuf: invalid buffer type\n");
>  		return -EINVAL;
>  	}
> +	ret = __verify_planes_array(q, b);
> +	if (ret)
> +		return ret;
>  
>  	ret = __vb2_get_done_vb(q, &vb, nonblocking);
>  	if (ret < 0) {

--

Regards,
Sylwester