On Wed, 2019-01-16 at 16:28 +0100, Hans Verkuil wrote:
> On 1/11/19 12:10 PM, Philipp Zabel wrote:
> > Prepare for mbus format being smaller than the written rectangle
> > due to burst size.
> >
> > Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
> > Reviewed-by: Steve Longerbeam <slongerb...@gmail.com>
> > ---
> > drivers/staging/media/imx/imx-media-capture.c | 56 +++++++++++++------
> > 1 file changed, 38 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/staging/media/imx/imx-media-capture.c
> > b/drivers/staging/media/imx/imx-media-capture.c
> > index fb985e68f9ab..614e335fb61c 100644
> > --- a/drivers/staging/media/imx/imx-media-capture.c
> > +++ b/drivers/staging/media/imx/imx-media-capture.c
> > @@ -203,21 +203,13 @@ static int capture_g_fmt_vid_cap(struct file *file,
> > void *fh,
> > return 0;
> > }
> >
> > -static int capture_try_fmt_vid_cap(struct file *file, void *fh,
> > - struct v4l2_format *f)
> > +static int __capture_try_fmt_vid_cap(struct capture_priv *priv,
> > + struct v4l2_subdev_format *fmt_src,
> > + struct v4l2_format *f)
> > {
> > - struct capture_priv *priv = video_drvdata(file);
> > - struct v4l2_subdev_format fmt_src;
> > const struct imx_media_pixfmt *cc, *cc_src;
> > - int ret;
> >
> > - fmt_src.pad = priv->src_sd_pad;
> > - fmt_src.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > - ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
> > - if (ret)
> > - return ret;
> > -
> > - cc_src = imx_media_find_ipu_format(fmt_src.format.code, CS_SEL_ANY);
> > + cc_src = imx_media_find_ipu_format(fmt_src->format.code, CS_SEL_ANY);
> > if (cc_src) {
> > u32 fourcc, cs_sel;
> >
> > @@ -231,7 +223,7 @@ static int capture_try_fmt_vid_cap(struct file *file,
> > void *fh,
> > cc = imx_media_find_format(fourcc, cs_sel, false);
> > }
> > } else {
> > - cc_src = imx_media_find_mbus_format(fmt_src.format.code,
> > + cc_src = imx_media_find_mbus_format(fmt_src->format.code,
> > CS_SEL_ANY, true);
> > if (WARN_ON(!cc_src))
> > return -EINVAL;
> > @@ -239,15 +231,32 @@ static int capture_try_fmt_vid_cap(struct file *file,
> > void *fh,
> > cc = cc_src;
> > }
> >
> > - imx_media_mbus_fmt_to_pix_fmt(&f->fmt.pix, &fmt_src.format, cc);
> > + imx_media_mbus_fmt_to_pix_fmt(&f->fmt.pix, &fmt_src->format, cc);
> >
> > return 0;
> > }
> >
> > +static int capture_try_fmt_vid_cap(struct file *file, void *fh,
> > + struct v4l2_format *f)
> > +{
> > + struct capture_priv *priv = video_drvdata(file);
> > + struct v4l2_subdev_format fmt_src;
> > + int ret;
> > +
> > + fmt_src.pad = priv->src_sd_pad;
> > + fmt_src.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > + ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
> > + if (ret)
> > + return ret;
> > +
> > + return __capture_try_fmt_vid_cap(priv, &fmt_src, f);
> > +}
> > +
> > static int capture_s_fmt_vid_cap(struct file *file, void *fh,
> > struct v4l2_format *f)
> > {
> > struct capture_priv *priv = video_drvdata(file);
> > + struct v4l2_subdev_format fmt_src;
> > int ret;
> >
> > if (vb2_is_busy(&priv->q)) {
> > @@ -255,7 +264,13 @@ static int capture_s_fmt_vid_cap(struct file *file,
> > void *fh,
> > return -EBUSY;
> > }
> >
> > - ret = capture_try_fmt_vid_cap(file, priv, f);
> > + fmt_src.pad = priv->src_sd_pad;
> > + fmt_src.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > + ret = v4l2_subdev_call(priv->src_sd, pad, get_fmt, NULL, &fmt_src);
> > + if (ret)
> > + return ret;
> > +
> > + ret = __capture_try_fmt_vid_cap(priv, &fmt_src, f);
> > if (ret)
> > return ret;
> >
> > @@ -264,8 +279,8 @@ static int capture_s_fmt_vid_cap(struct file *file,
> > void *fh,
> > CS_SEL_ANY, true);
> > priv->vdev.compose.left = 0;
> > priv->vdev.compose.top = 0;
> > - priv->vdev.compose.width = f->fmt.pix.width;
> > - priv->vdev.compose.height = f->fmt.pix.height;
> > + priv->vdev.compose.width = fmt_src.format.width;
> > + priv->vdev.compose.height = fmt_src.format.height;
> >
> > return 0;
> > }
> > @@ -306,9 +321,14 @@ static int capture_g_selection(struct file *file, void
> > *fh,
> > case V4L2_SEL_TGT_COMPOSE:
> > case V4L2_SEL_TGT_COMPOSE_DEFAULT:
> > case V4L2_SEL_TGT_COMPOSE_BOUNDS:
> > - case V4L2_SEL_TGT_COMPOSE_PADDED:
> > s->r = priv->vdev.compose;
> > break;
> > + case V4L2_SEL_TGT_COMPOSE_PADDED:
>
> Shouldn't this be for COMPOSE_BOUNDS as well?
COMPOSE_BOUNDS specifies the bounds in which COMPOSE can be set. Since
we don't allow changing COMPOSE at all, COMPOSE/BOUNDS/DEFAULT should
all be the same.
COMPOSE_PADDED is larger than the fixed COMPOSE rectangle on the right
side to align to DMA burst size.
> Do you need _PADDED at all? That only makes sense if the DMA writes beyond
> the COMPOSE rectangle due to padding requirements. I'm not aware that that's
> the case for imx.
> I may be wrong, this would be correct if the DMA indeed
> writes the full buffer, even if the actual image is smaller.
That's exactly what happens, the hardware writes with a fixed burst size
and doesn't support partial bursts as far as I am aware.
If the video input signal width is not a multiple of DMA burst size, the
last written burst of each line does contain some invalid padding pixels
at the end.
> > + s->r.left = 0;
> > + s->r.top = 0;
> > + s->r.width = priv->vdev.fmt.fmt.pix.width;
> > + s->r.height = priv->vdev.fmt.fmt.pix.height;
> > + break;
> > default:
> > return -EINVAL;
> > }
> >
>
> I see that the image is always DMAed to the top-left corner of the buffer.
>
> Is there a need to implement s_selection so you can change the top-left
> corner of the compose rectangle within the buffer?
I haven't seen a use case for this, but I'm curious how that is supposed
to work. Currently we are limiting buffer width/height in S_FMT to the
connected subdevice's mbus format width / height.
After this we'd have to allow any width / height larger than mbus format
and limit compose rectangle width/height to the mbus format?
regards
Philipp
