[PATCH v3 17/24] media: imx: Add CSI subdev driver

On Fri, 2017-01-06 at 18:11 -0800, Steve Longerbeam wrote:
[...]

+static int csi_set_fmt(struct v4l2_subdev *sd,
+		       struct v4l2_subdev_pad_config *cfg,
+		       struct v4l2_subdev_format *sdformat)
+{
+	struct csi_priv *priv = v4l2_get_subdevdata(sd);
+	struct v4l2_mbus_framefmt *infmt, *outfmt;
+	struct v4l2_rect crop;
+	int ret;
+
+	if (sdformat->pad >= CSI_NUM_PADS)
+		return -EINVAL;
+
+	if (priv->stream_on)
+		return -EBUSY;
+
+	infmt = &priv->format_mbus[priv->input_pad];
+	outfmt = &priv->format_mbus[priv->output_pad];
+
+	if (sdformat->pad == priv->output_pad) {
+		sdformat->format.code = infmt->code;
+		sdformat->format.field = infmt->field;
+		crop.left = priv->crop.left;
+		crop.top = priv->crop.top;
+		crop.width = sdformat->format.width;
+		crop.height = sdformat->format.height;
+		ret = csi_try_crop(priv, &crop);

This is the wrong way around, see also below.

Here the the output sdformat->format.width/height should be set to the
priv->crop.width/height (or priv->crop.width/height / 2, to enable
downscaling). The crop rectangle should not be changed by an output pad
set_fmt.

+		if (ret)
+			return ret;
+		sdformat->format.width = crop.width;
+		sdformat->format.height = crop.height;
+	}
+
+	if (sdformat->which == V4L2_SUBDEV_FORMAT_TRY) {
+		cfg->try_fmt = sdformat->format;
+	} else {
+		priv->format_mbus[sdformat->pad] = sdformat->format;
+		/* Update the crop window if this is output pad  */
+		if (sdformat->pad == priv->output_pad)
+			priv->crop = crop;

The crop rectangle instead should be reset to the full input frame when
the input pad format is set.

regards
Philipp