Re: [RFC PATCH v9 1/6] media: videobuf2: Move timestamp to vb2_buffer

[Hans Verkuil <hverkuil@xs4all.nl>]

On 11/03/15 11:16, Junghak Sung wrote:
> Move timestamp from struct vb2_v4l2_buffer to struct vb2_buffer
> for common use, and change its type to u64 in order to handling
> y2038 problem. This patch also includes all device drivers' changes related to
> this restructuring.
> 
> Signed-off-by: Junghak Sung <jh1009.sung@samsung.com>
> Signed-off-by: Geunyoung Kim <nenggun.kim@samsung.com>
> Acked-by: Seung-Woo Kim <sw0312.kim@samsung.com>
> Acked-by: Inki Dae <inki.dae@samsung.com>
> ---

<snip>

> diff --git a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> index 1bd2fd4..61df3e4 100644
> --- a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
> @@ -531,8 +531,8 @@ static int solo_enc_fillbuf(struct solo_enc_dev *solo_enc,
>  
>  	if (!ret) {
>  		vbuf->sequence = solo_enc->sequence++;
> -		vbuf->timestamp.tv_sec = vop_sec(vh);
> -		vbuf->timestamp.tv_usec = vop_usec(vh);
> +		vb->timestamp = ((u64) vop_sec(vh) * NSEC_PER_SEC) +
> +				(vop_usec(vh) * NSEC_PER_USEC);

This is wrong. Just use ktime_get_ns() here. It is probably best to first make a
single patch to change the solo driver to use v4l2_get_timestamp(), then convert
that to ktime_get_ns() in this patch.

The problem is that the timestamp is taken from the mpeg header, and so it is
not a CLOCK_MONOTONIC timestamp as is signaled to the user. Never noticed this
before, but it is a solo driver bug.

>  
>  		/* Check for motion flags */
>  		if (solo_is_motion_on(solo_enc) && enc_buf->motion) {
> diff --git a/drivers/media/pci/solo6x10/solo6x10-v4l2.c b/drivers/media/pci/solo6x10/solo6x10-v4l2.c
> index 26df903..44b00b8 100644
> --- a/drivers/media/pci/solo6x10/solo6x10-v4l2.c
> +++ b/drivers/media/pci/solo6x10/solo6x10-v4l2.c
> @@ -225,7 +225,7 @@ finish_buf:
>  		vb2_set_plane_payload(vb, 0,
>  			solo_vlines(solo_dev) * solo_bytesperline(solo_dev));
>  		vbuf->sequence = solo_dev->sequence++;
> -		v4l2_get_timestamp(&vbuf->timestamp);
> +		vb->timestamp = ktime_get_ns();
>  	}
>  
>  	vb2_buffer_done(vb, error ? VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);

<snip>

> diff --git a/drivers/media/platform/vivid/vivid-kthread-cap.c b/drivers/media/platform/vivid/vivid-kthread-cap.c
> index 83cc6d3..b0ad054 100644
> --- a/drivers/media/platform/vivid/vivid-kthread-cap.c
> +++ b/drivers/media/platform/vivid/vivid-kthread-cap.c
> @@ -441,7 +441,7 @@ static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
>  	 * "Start of Exposure".
>  	 */
>  	if (dev->tstamp_src_is_soe)
> -		v4l2_get_timestamp(&buf->vb.timestamp);
> +		buf->vb.vb2_buf.timestamp = ktime_get_ns();
>  	if (dev->field_cap == V4L2_FIELD_ALTERNATE) {
>  		/*
>  		 * 60 Hz standards start with the bottom field, 50 Hz standards
> @@ -558,8 +558,9 @@ static void vivid_fillbuff(struct vivid_dev *dev, struct vivid_buffer *buf)
>  	 * the timestamp now.
>  	 */
>  	if (!dev->tstamp_src_is_soe)
> -		v4l2_get_timestamp(&buf->vb.timestamp);
> -	buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +		buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +	buf->vb.vb2_buf.timestamp +=
> +			((u64) dev->time_wrap_offset * NSEC_PER_SEC);

I'd do this differently: make time_wrap_offset of type u64 and assign it
accordingly with nanoseconds. That way you can just do:

	timestamp += dev->time_wrap_offset

vivid-ctrls.c also needs to be modified (vivid_streaming_s_ctrl(), VIVID_CID_TIME_WRAP
case) to:

	dev->time_wrap_offset = (0x100000000ULL - 16) * NSEC_PER_SEC - ktime_get_ns();

The v4l2_get_timestamp() call there can be dropped.

>  }
>  
>  /*
> diff --git a/drivers/media/platform/vivid/vivid-kthread-out.c b/drivers/media/platform/vivid/vivid-kthread-out.c
> index c2c46dc..6fd02c9 100644
> --- a/drivers/media/platform/vivid/vivid-kthread-out.c
> +++ b/drivers/media/platform/vivid/vivid-kthread-out.c
> @@ -95,8 +95,9 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
>  			 */
>  			vid_out_buf->vb.sequence /= 2;
>  		}
> -		v4l2_get_timestamp(&vid_out_buf->vb.timestamp);
> -		vid_out_buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +		vid_out_buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +		vid_out_buf->vb.vb2_buf.timestamp +=
> +				((u64) dev->time_wrap_offset * NSEC_PER_SEC);
>  		vb2_buffer_done(&vid_out_buf->vb.vb2_buf, dev->dqbuf_error ?
>  				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
>  		dprintk(dev, 2, "vid_out buffer %d done\n",
> @@ -108,8 +109,9 @@ static void vivid_thread_vid_out_tick(struct vivid_dev *dev)
>  			vivid_sliced_vbi_out_process(dev, vbi_out_buf);
>  
>  		vbi_out_buf->vb.sequence = dev->vbi_out_seq_count;
> -		v4l2_get_timestamp(&vbi_out_buf->vb.timestamp);
> -		vbi_out_buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +		vbi_out_buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +		vbi_out_buf->vb.vb2_buf.timestamp +=
> +				((u64) dev->time_wrap_offset * NSEC_PER_SEC);
>  		vb2_buffer_done(&vbi_out_buf->vb.vb2_buf, dev->dqbuf_error ?
>  				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
>  		dprintk(dev, 2, "vbi_out buffer %d done\n",
> diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c
> index 082c401..dbdb43d 100644
> --- a/drivers/media/platform/vivid/vivid-sdr-cap.c
> +++ b/drivers/media/platform/vivid/vivid-sdr-cap.c
> @@ -117,8 +117,9 @@ static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
>  	if (sdr_cap_buf) {
>  		sdr_cap_buf->vb.sequence = dev->sdr_cap_seq_count;
>  		vivid_sdr_cap_process(dev, sdr_cap_buf);
> -		v4l2_get_timestamp(&sdr_cap_buf->vb.timestamp);
> -		sdr_cap_buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +		sdr_cap_buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +		sdr_cap_buf->vb.vb2_buf.timestamp +=
> +				((u64) dev->time_wrap_offset * NSEC_PER_SEC);
>  		vb2_buffer_done(&sdr_cap_buf->vb.vb2_buf, dev->dqbuf_error ?
>  				VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
>  		dev->dqbuf_error = false;
> diff --git a/drivers/media/platform/vivid/vivid-vbi-cap.c b/drivers/media/platform/vivid/vivid-vbi-cap.c
> index e903d02..2f5f330 100644
> --- a/drivers/media/platform/vivid/vivid-vbi-cap.c
> +++ b/drivers/media/platform/vivid/vivid-vbi-cap.c
> @@ -108,8 +108,9 @@ void vivid_raw_vbi_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
>  	if (!VIVID_INVALID_SIGNAL(dev->std_signal_mode))
>  		vivid_vbi_gen_raw(&dev->vbi_gen, &vbi, vbuf);
>  
> -	v4l2_get_timestamp(&buf->vb.timestamp);
> -	buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +	buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +	buf->vb.vb2_buf.timestamp +=
> +			((u64) dev->time_wrap_offset * NSEC_PER_SEC);
>  }
>  
>  
> @@ -133,8 +134,9 @@ void vivid_sliced_vbi_cap_process(struct vivid_dev *dev,
>  			vbuf[i] = dev->vbi_gen.data[i];
>  	}
>  
> -	v4l2_get_timestamp(&buf->vb.timestamp);
> -	buf->vb.timestamp.tv_sec += dev->time_wrap_offset;
> +	buf->vb.vb2_buf.timestamp = ktime_get_ns();
> +	buf->vb.vb2_buf.timestamp +=
> +			((u64) dev->time_wrap_offset * NSEC_PER_SEC);
>  }
>  
>  static int vbi_cap_queue_setup(struct vb2_queue *vq, const void *parg,

<snip>

> diff --git a/drivers/media/v4l2-core/videobuf2-v4l2.c b/drivers/media/v4l2-core/videobuf2-v4l2.c
> index 27b4b9e..93e16375 100644
> --- a/drivers/media/v4l2-core/videobuf2-v4l2.c
> +++ b/drivers/media/v4l2-core/videobuf2-v4l2.c
> @@ -119,8 +119,9 @@ static int __set_timestamp(struct vb2_buffer *vb, const void *pb)
>  		 * and the timecode field and flag if needed.
>  		 */
>  		if ((q->timestamp_flags & V4L2_BUF_FLAG_TIMESTAMP_MASK) ==
> -				V4L2_BUF_FLAG_TIMESTAMP_COPY)
> -			vbuf->timestamp = b->timestamp;
> +				V4L2_BUF_FLAG_TIMESTAMP_COPY) {
> +			vb->timestamp = timeval_to_ns(&b->timestamp);
> +		}

No need to add {} for a one-line statement.

>  		vbuf->flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
>  		if (b->flags & V4L2_BUF_FLAG_TIMECODE)
>  			vbuf->timecode = b->timecode;

<snip>

> diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
> index 647ebfe..6404f81 100644
> --- a/include/media/videobuf2-core.h
> +++ b/include/media/videobuf2-core.h
> @@ -211,6 +211,7 @@ struct vb2_queue;
>   * @num_planes:		number of planes in the buffer
>   *			on an internal driver queue
>   * @planes:		private per-plane information; do not change
> + * @timestamp:		frame timestamp

Please mention the unit (ns).

>   */
>  struct vb2_buffer {
>  	struct vb2_queue	*vb2_queue;
> @@ -219,6 +220,7 @@ struct vb2_buffer {
>  	unsigned int		memory;
>  	unsigned int		num_planes;
>  	struct vb2_plane	planes[VB2_MAX_PLANES];
> +	u64			timestamp;
>  
>  	/* private: internal use only
>  	 *

Other than these minor issues it looks good.

Regards,

	Hans