Re: [REVIEWv2 PATCH 05/15] vb2: change result code of buf_finish to void

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Thursday 27 February 2014 12:23:58 Laurent Pinchart wrote:
> On Tuesday 25 February 2014 13:52:45 Hans Verkuil wrote:
> > From: Hans Verkuil <hans.verkuil@cisco.com>
> > 
> > The buf_finish op should always work, so change the return type to void.
> > Update the few drivers that use it. Note that buf_finish can be called
> > both when the DMA is streaming and when it isn't (during queue_cancel).
> 
> I'm not sure what branch this series is based on, but in the latest linuxtv
> master branch buf_finish is only called from vb2_internal_dqbuf(), itself
> only called from vb2_dqbuf() and __vb2_perform_fileio().

And I should have read the next patches before commenting on this :-)

> I would split the patch in two, one patch to change the buf_finish behaviour
> inside the drivers and update the buf_finish documentation to explain when
> it can be called in more details, and another one to change its return
> value to void.

Let's reorder the patches if you don't mind. I would still split this as 
described in 5.1 and 5.2. I would then move 5.2 before 5.1, and either squash 
6 with 5.1 or move 6 before 5.1.

> > Update drivers to check that where appropriate.
> > 
> > Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> > Acked-by: Pawel Osciak <pawel@osciak.com>
> > Reviewed-by: Pawel Osciak <pawel@osciak.com>
> > ---
> > 
> >  drivers/media/parport/bw-qcam.c                 |  6 ++++--
> >  drivers/media/pci/sta2x11/sta2x11_vip.c         |  7 +++----
> >  drivers/media/platform/marvell-ccic/mcam-core.c |  3 +--
> >  drivers/media/usb/pwc/pwc-if.c                  | 16 +++++++++-------
> >  drivers/media/usb/uvc/uvc_queue.c               |  6 +++---
> >  drivers/media/v4l2-core/videobuf2-core.c        |  6 +-----
> >  drivers/staging/media/go7007/go7007-v4l2.c      |  3 +--
> >  include/media/videobuf2-core.h                  |  2 +-
> >  8 files changed, 23 insertions(+), 26 deletions(-)
> > 
> > diff --git a/drivers/media/parport/bw-qcam.c
> > b/drivers/media/parport/bw-qcam.c index d12bd33..8d69bfb 100644
> > --- a/drivers/media/parport/bw-qcam.c
> > +++ b/drivers/media/parport/bw-qcam.c
> > @@ -667,13 +667,16 @@ static void buffer_queue(struct vb2_buffer *vb)
> > 
> >  	vb2_buffer_done(vb, VB2_BUF_STATE_DONE);
> >  
> >  }
> > 
> > -static int buffer_finish(struct vb2_buffer *vb)
> > +static void buffer_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct qcam *qcam = vb2_get_drv_priv(vb->vb2_queue);
> >  	void *vbuf = vb2_plane_vaddr(vb, 0);
> >  	int size = vb->vb2_queue->plane_sizes[0];
> >  	int len;
> > 
> > +	if (!vb2_is_streaming(vb->vb2_queue))
> > +		return;
> > +
> > 
> >  	mutex_lock(&qcam->lock);
> >  	parport_claim_or_block(qcam->pdev);
> > 
> > @@ -691,7 +694,6 @@ static int buffer_finish(struct vb2_buffer *vb)
> > 
> >  	if (len != size)
> >  	
> >  		vb->state = VB2_BUF_STATE_ERROR;
> >  	
> >  	vb2_set_plane_payload(vb, 0, len);
> > 
> > -	return 0;
> > 
> >  }
> >  
> >  static struct vb2_ops qcam_video_qops = {
> > 
> > diff --git a/drivers/media/pci/sta2x11/sta2x11_vip.c
> > b/drivers/media/pci/sta2x11/sta2x11_vip.c index e5cfb6c..bb11443 100644
> > --- a/drivers/media/pci/sta2x11/sta2x11_vip.c
> > +++ b/drivers/media/pci/sta2x11/sta2x11_vip.c
> > @@ -327,7 +327,7 @@ static void buffer_queue(struct vb2_buffer *vb)
> > 
> >  	}
> >  	spin_unlock(&vip->lock);
> >  
> >  }
> > 
> > -static int buffer_finish(struct vb2_buffer *vb)
> > +static void buffer_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct sta2x11_vip *vip = vb2_get_drv_priv(vb->vb2_queue);
> >  	struct vip_buffer *vip_buf = to_vip_buffer(vb);
> > 
> > @@ -337,9 +337,8 @@ static int buffer_finish(struct vb2_buffer *vb)
> > 
> >  	list_del_init(&vip_buf->list);
> >  	spin_unlock(&vip->lock);
> > 
> > -	vip_active_buf_next(vip);
> > -
> > -	return 0;
> > +	if (vb2_is_streaming(vb->vb2_queue))
> > +		vip_active_buf_next(vip);
> > 
> >  }
> >  
> >  static int start_streaming(struct vb2_queue *vq, unsigned int count)
> > 
> > diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c
> > b/drivers/media/platform/marvell-ccic/mcam-core.c index 32fab30..8b34c48
> > 100644
> > --- a/drivers/media/platform/marvell-ccic/mcam-core.c
> > +++ b/drivers/media/platform/marvell-ccic/mcam-core.c
> > @@ -1238,7 +1238,7 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer
> > *vb) return 0;
> > 
> >  }
> > 
> > -static int mcam_vb_sg_buf_finish(struct vb2_buffer *vb)
> > +static void mcam_vb_sg_buf_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
> >  	struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
> > 
> > @@ -1246,7 +1246,6 @@ static int mcam_vb_sg_buf_finish(struct vb2_buffer
> > *vb) if (sg_table)
> > 
> >  		dma_unmap_sg(cam->dev, sg_table->sgl,
> >  		
> >  				sg_table->nents, DMA_FROM_DEVICE);
> > 
> > -	return 0;
> > 
> >  }
> >  
> >  static void mcam_vb_sg_buf_cleanup(struct vb2_buffer *vb)
> > 
> > diff --git a/drivers/media/usb/pwc/pwc-if.c
> > b/drivers/media/usb/pwc/pwc-if.c index abf365a..b9c9f10 100644
> > --- a/drivers/media/usb/pwc/pwc-if.c
> > +++ b/drivers/media/usb/pwc/pwc-if.c
> > @@ -614,17 +614,19 @@ static int buffer_prepare(struct vb2_buffer *vb)
> > 
> >  	return 0;
> >  
> >  }
> > 
> > -static int buffer_finish(struct vb2_buffer *vb)
> > +static void buffer_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct pwc_device *pdev = vb2_get_drv_priv(vb->vb2_queue);
> >  	struct pwc_frame_buf *buf = container_of(vb, struct pwc_frame_buf, 
vb);
> > 
> > -	/*
> > -	 * Application has called dqbuf and is getting back a buffer we've
> > -	 * filled, take the pwc data we've stored in buf->data and decompress
> > -	 * it into a usable format, storing the result in the vb2_buffer
> > -	 */
> > -	return pwc_decompress(pdev, buf);
> > +	if (vb->state == VB2_BUF_STATE_DONE) {
> > +		/*
> > +		 * Application has called dqbuf and is getting back a buffer 
we've
> > +		 * filled, take the pwc data we've stored in buf->data and 
decompress
> > +		 * it into a usable format, storing the result in the vb2_buffer
> > +		 */
> > +		pwc_decompress(pdev, buf);
> > +	}
> > 
> >  }
> >  
> >  static void buffer_cleanup(struct vb2_buffer *vb)
> > 
> > diff --git a/drivers/media/usb/uvc/uvc_queue.c
> > b/drivers/media/usb/uvc/uvc_queue.c index cd962be..db5984e 100644
> > --- a/drivers/media/usb/uvc/uvc_queue.c
> > +++ b/drivers/media/usb/uvc/uvc_queue.c
> > @@ -104,15 +104,15 @@ static void uvc_buffer_queue(struct vb2_buffer *vb)
> > 
> >  	spin_unlock_irqrestore(&queue->irqlock, flags);
> >  
> >  }
> > 
> > -static int uvc_buffer_finish(struct vb2_buffer *vb)
> > +static void uvc_buffer_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue);
> >  	struct uvc_streaming *stream =
> >  	
> >  			container_of(queue, struct uvc_streaming, queue);
> >  	
> >  	struct uvc_buffer *buf = container_of(vb, struct uvc_buffer, buf);
> > 
> > -	uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
> > -	return 0;
> > +	if (vb2_is_streaming(vb->vb2_queue))
> > +		uvc_video_clock_update(stream, &vb->v4l2_buf, buf);
> > 
> >  }
> >  
> >  static void uvc_wait_prepare(struct vb2_queue *vq)
> > 
> > diff --git a/drivers/media/v4l2-core/videobuf2-core.c
> > b/drivers/media/v4l2-core/videobuf2-core.c index 8f1578b..59bfd85 100644
> > --- a/drivers/media/v4l2-core/videobuf2-core.c
> > +++ b/drivers/media/v4l2-core/videobuf2-core.c
> > @@ -1783,11 +1783,7 @@ static int vb2_internal_dqbuf(struct vb2_queue *q,
> > struct v4l2_buffer *b, bool n if (ret < 0)
> > 
> >  		return ret;
> > 
> > -	ret = call_vb_qop(vb, buf_finish, vb);
> > -	if (ret) {
> > -		dprintk(1, "dqbuf: buffer finish failed\n");
> > -		return ret;
> > -	}
> > +	call_vb_qop(vb, buf_finish, vb);
> > 
> >  	switch (vb->state) {
> > 
> >  	case VB2_BUF_STATE_DONE:
> > diff --git a/drivers/staging/media/go7007/go7007-v4l2.c
> > b/drivers/staging/media/go7007/go7007-v4l2.c index edc52e2..3a01576 100644
> > --- a/drivers/staging/media/go7007/go7007-v4l2.c
> > +++ b/drivers/staging/media/go7007/go7007-v4l2.c
> > @@ -470,7 +470,7 @@ static int go7007_buf_prepare(struct vb2_buffer *vb)
> > 
> >  	return 0;
> >  
> >  }
> > 
> > -static int go7007_buf_finish(struct vb2_buffer *vb)
> > +static void go7007_buf_finish(struct vb2_buffer *vb)
> > 
> >  {
> >  
> >  	struct vb2_queue *vq = vb->vb2_queue;
> >  	struct go7007 *go = vb2_get_drv_priv(vq);
> > 
> > @@ -483,7 +483,6 @@ static int go7007_buf_finish(struct vb2_buffer *vb)
> > 
> >  			V4L2_BUF_FLAG_PFRAME);
> >  	
> >  	buf->flags |= frame_type_flag;
> >  	buf->field = V4L2_FIELD_NONE;
> > 
> > -	return 0;
> > 
> >  }
> >  
> >  static int go7007_start_streaming(struct vb2_queue *q, unsigned int
> >  count)
> > 
> > diff --git a/include/media/videobuf2-core.h
> > b/include/media/videobuf2-core.h index f04eb28..f443ce0 100644
> > --- a/include/media/videobuf2-core.h
> > +++ b/include/media/videobuf2-core.h
> > @@ -311,7 +311,7 @@ struct vb2_ops {
> > 
> >  	int (*buf_init)(struct vb2_buffer *vb);
> >  	int (*buf_prepare)(struct vb2_buffer *vb);
> > 
> > -	int (*buf_finish)(struct vb2_buffer *vb);
> > +	void (*buf_finish)(struct vb2_buffer *vb);
> > 
> >  	void (*buf_cleanup)(struct vb2_buffer *vb);
> >  	
> >  	int (*start_streaming)(struct vb2_queue *q, unsigned int count);

-- 
Regards,

Laurent Pinchart