Re: [RFC PATCH v2 12/18] media: tegra-video: Add support for selection ioctl ops

[Sowjanya Komatineni <skomatineni@xxxxxxxxxx>]

On 7/3/20 1:06 AM, Hans Verkuil wrote:
> On 02/07/2020 23:20, Sowjanya Komatineni wrote:
> > On 7/2/20 6:54 AM, Hans Verkuil wrote:
> > > On 17/06/2020 03:41, Sowjanya Komatineni wrote:
> > > > This patch adds selection v4l2 ioctl operations to allow configuring
> > > > a selection rectangle in the sensor through the Tegra video device
> > > > node.
> > > >
> > > > Some sensor drivers supporting crop uses try_crop rectangle from
> > > > v4l2_subdev_pad_config during try format for computing binning.
> > > >
> > > > So with selection ops support, this patch also updates try format
> > > > to use try crop rectangle either from subdev frame size enumeration
> > > > or from subdev crop boundary.
> > > >
> > > > Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> > > > ---
> > > >    drivers/staging/media/tegra-video/vi.c | 106 +++++++++++++++++++++++++++++++++
> > > >    1 file changed, 106 insertions(+)
> > > >
> > > > diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
> > > > index 506c263..f9eb96b 100644
> > > > --- a/drivers/staging/media/tegra-video/vi.c
> > > > +++ b/drivers/staging/media/tegra-video/vi.c
> > > > @@ -427,6 +427,13 @@ static int __tegra_channel_try_format(struct tegra_vi_channel *chan,
> > > >    	struct v4l2_subdev *subdev;
> > > >    	struct v4l2_subdev_format fmt;
> > > >    	struct v4l2_subdev_pad_config *pad_cfg;
> > > > +	struct v4l2_subdev_frame_size_enum fse = {
> > > > +		.which = V4L2_SUBDEV_FORMAT_TRY,
> > > > +	};
> > > > +	struct v4l2_subdev_selection sdsel = {
> > > > +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > > > +		.target = V4L2_SEL_TGT_CROP_BOUNDS,
> > > > +	};
> > > >    	int ret;
> > > >    
> > > >    	subdev = tegra_channel_get_remote_subdev(chan, true);
> > > > @@ -449,6 +456,24 @@ static int __tegra_channel_try_format(struct tegra_vi_channel *chan,
> > > >    	fmt.which = V4L2_SUBDEV_FORMAT_TRY;
> > > >    	fmt.pad = 0;
> > > >    	v4l2_fill_mbus_format(&fmt.format, pix, fmtinfo->code);
> > > > +
> > > > +	/*
> > > > +	 * Attempt to obtain the format size from subdev.
> > > > +	 * If not available, try to get crop boundary from subdev.
> > > > +	 */
> > > > +	fse.code = fmtinfo->code;
> > > > +	ret = v4l2_subdev_call(subdev, pad, enum_frame_size, pad_cfg, &fse);
> > > > +	if (ret) {
> > > > +		ret = v4l2_subdev_call(subdev, pad, get_selection, NULL, &sdsel);
> > > > +		if (ret)
> > > > +			return -EINVAL;
> > > > +		pad_cfg->try_crop.width = sdsel.r.width;
> > > > +		pad_cfg->try_crop.height = sdsel.r.height;
> > > > +	} else {
> > > > +		pad_cfg->try_crop.width = fse.max_width;
> > > > +		pad_cfg->try_crop.height = fse.max_height;
> > > > +	}
> > > > +
> > > >    	ret = v4l2_subdev_call(subdev, pad, set_fmt, pad_cfg, &fmt);
> > > >    	if (ret < 0)
> > > >    		return ret;
> > > > @@ -540,6 +565,85 @@ static int tegra_channel_set_subdev_active_fmt(struct tegra_vi_channel *chan)
> > > >    	return 0;
> > > >    }
> > > >    
> > > > +static int tegra_channel_g_selection(struct file *file, void *priv,
> > > > +				     struct v4l2_selection *sel)
> > > > +{
> > > > +	struct tegra_vi_channel *chan = video_drvdata(file);
> > > > +	struct v4l2_subdev *subdev;
> > > > +	struct v4l2_subdev_format fmt = {
> > > > +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > > > +	};
> > > > +	struct v4l2_subdev_selection sdsel = {
> > > > +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > > > +		.target = sel->target,
> > > > +	};
> > > > +	int ret;
> > > > +
> > > > +	if (IS_ENABLED(CONFIG_VIDEO_TEGRA_TPG))
> > > > +		return -ENOTTY;
> > > > +
> > > > +	if (sel->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> > > > +		return -EINVAL;
> > > > +	/*
> > > > +	 * Try the get selection operation and fallback to get format if not
> > > > +	 * implemented.
> > > > +	 */
> > > > +	subdev = tegra_channel_get_remote_subdev(chan, true);
> > > > +	ret = v4l2_subdev_call(subdev, pad, get_selection, NULL, &sdsel);
> > > > +	if (!ret)
> > > > +		sel->r = sdsel.r;
> > > > +	if (ret != -ENOIOCTLCMD)
> > > > +		return ret;
> > > > +
> > > > +	ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
> > > > +	if (ret < 0)
> > > > +		return ret;
> > > > +
> > > > +	sel->r.left = 0;
> > > > +	sel->r.top = 0;
> > > > +	sel->r.width = fmt.format.width;
> > > > +	sel->r.height = fmt.format.height;
> > > > +
> > > > +	return 0;
> > > > +}
> > > > +
> > > > +static int tegra_channel_s_selection(struct file *file, void *fh,
> > > > +				     struct v4l2_selection *sel)
> > > > +{
> > > > +	struct tegra_vi_channel *chan = video_drvdata(file);
> > > > +	struct v4l2_subdev *subdev;
> > > > +	int ret;
> > > > +	struct v4l2_subdev_selection sdsel = {
> > > > +		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
> > > > +		.target = sel->target,
> > > > +		.flags = sel->flags,
> > > > +		.r = sel->r,
> > > > +	};
> > > > +
> > > This function doesn't check if the subdev actually supports set_selection.
> > > The imx219 is one such driver: it supports get_selection, but not set_selection.
> > >
> > > So this code should add these lines to fix the v4l2-compliance fail:
> > >
> > >          subdev = tegra_channel_get_remote_subdev(chan, true);
> > >
> > >          if (!v4l2_subdev_has_op(subdev, pad, set_selection))
> > >                  return -ENOTTY;
> > v4l2_subdev_call() does that check and returns -ENOIOCTLCMD when
> > specified subdev ops does not exist.
> But that test happens too late. In the v4l2-compliance test it fails in the
> sel->type test below, so it returns EINVAL instead of ENOTTY.
>
> > > > +	if (IS_ENABLED(CONFIG_VIDEO_TEGRA_TPG))
> > > > +		return -ENOTTY;
> I think this test should come before the v4l2_subdev_has_op test since there
> is probably no subdev if the TPG is enabled. So:
>
> 	if (IS_ENABLED(CONFIG_VIDEO_TEGRA_TPG))
> 		return -ENOTTY;
>
>          subdev = tegra_channel_get_remote_subdev(chan, true);
>          if (!v4l2_subdev_has_op(subdev, pad, set_selection))
>                  return -ENOTTY;
>
>
> Regards,
>
> 	Hans
OK Will update in v3. Thanks Hans
> > > > +
> > > > +	if (sel->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> > > > +		return -EINVAL;
> > > > +
> > > > +	if (vb2_is_busy(&chan->queue))
> > > > +		return -EBUSY;
> > > > +
> > > > +	subdev = tegra_channel_get_remote_subdev(chan, true);
> > > And this line can be dropped.
> > >
> > > Regards,
> > >
> > > 	Hans
> > >
> > > > +	ret = v4l2_subdev_call(subdev, pad, set_selection, NULL, &sdsel);
> > > > +	if (!ret) {
> > > > +		sel->r = sdsel.r;
> > > > +		/*
> > > > +		 * Subdev active format resolution may have changed during
> > > > +		 * set selection operation. So, update channel format to
> > > > +		 * the sub-device active format.
> > > > +		 */
> > > > +		return tegra_channel_set_subdev_active_fmt(chan);
> > > > +	}
> > > > +
> > > > +	return ret;
> > > > +}
> > > > +
> > > >    static int tegra_channel_enum_input(struct file *file, void *fh,
> > > >    				    struct v4l2_input *inp)
> > > >    {
> > > > @@ -597,6 +701,8 @@ static const struct v4l2_ioctl_ops tegra_channel_ioctl_ops = {
> > > >    	.vidioc_streamoff		= vb2_ioctl_streamoff,
> > > >    	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
> > > >    	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
> > > > +	.vidioc_g_selection		= tegra_channel_g_selection,
> > > > +	.vidioc_s_selection		= tegra_channel_s_selection,
> > > >    };
> > > >    
> > > >    /*