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

[Philipp Zabel <p.zabel@pengutronix.de>]

On Tue, 2017-01-31 at 16:51 +0100, Philipp Zabel wrote:
> 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.
[...]
> The crop rectangle instead should be reset to the full input frame when
> the input pad format is set.

How about this:

----------8<----------
diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 5e80a0871b139..8220e4204a125 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -484,6 +484,8 @@ static int csi_setup(struct csi_priv *priv)
 	if_fmt.field = outfmt->field;
 
 	ipu_csi_set_window(priv->csi, &priv->crop);
+	ipu_csi_set_downsize(priv->csi, priv->crop.width == 2 * outfmt->width,
+					priv->crop.height == 2 * outfmt->height);
 
 	ipu_csi_init_interface(priv->csi, &sensor_mbus_cfg, &if_fmt);
 
@@ -830,15 +832,14 @@ static int csi_set_fmt(struct v4l2_subdev *sd,
 	switch (sdformat->pad) {
 	case CSI_SRC_PAD_DIRECT:
 	case CSI_SRC_PAD_IDMAC:
-		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, sensor);
-		if (ret)
-			return ret;
-		sdformat->format.width = crop.width;
-		sdformat->format.height = crop.height;
+		if (sdformat->format.width < priv->crop.width * 3 / 4)
+			sdformat->format.width = priv->crop.width / 2;
+		else
+			sdformat->format.width = priv->crop.width;
+		if (sdformat->format.height < priv->crop.height * 3 / 4)
+			sdformat->format.height = priv->crop.height / 2;
+		else
+			sdformat->format.height = priv->crop.height;
 
 		if (sdformat->pad == CSI_SRC_PAD_IDMAC) {
 			cc = imx_media_find_format(0, sdformat->format.code,
@@ -887,6 +888,14 @@ static int csi_set_fmt(struct v4l2_subdev *sd,
 		}
 		break;
 	case CSI_SINK_PAD:
+		crop.left = 0;
+		crop.top = 0;
+		crop.width = sdformat->format.width;
+		crop.height = sdformat->format.height;
+		ret = csi_try_crop(priv, &crop, sensor);
+		if (ret)
+			return ret;
+
 		cc = imx_media_find_format(0, sdformat->format.code,
 					   true, false);
 		if (!cc) {
@@ -904,9 +913,8 @@ static int csi_set_fmt(struct v4l2_subdev *sd,
 	} else {
 		priv->format_mbus[sdformat->pad] = sdformat->format;
 		priv->cc[sdformat->pad] = cc;
-		/* Update the crop window if this is an output pad  */
-		if (sdformat->pad == CSI_SRC_PAD_DIRECT ||
-		    sdformat->pad == CSI_SRC_PAD_IDMAC)
+		/* Reset the crop window if this is the input pad  */
+		if (sdformat->pad == CSI_SINK_PAD)
 			priv->crop = crop;
 	}
 
---------->8----------

regards
Philipp