media: imx: csi: Stop upstream before disabling IDMA channel

Move upstream stream off to just after receiving the last EOF completion
and disabling the CSI (and thus before disabling the IDMA channel) in
csi_stop(). For symmetry also move upstream stream on to beginning of
csi_start().

Doing this makes csi_s_stream() more symmetric with prp_s_stream() which
will require the same change to fix a hard lockup.
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Cc: stable@vger.kernel.org	# for 4.13 and up
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/staging/media/imx/imx-media-csi.c

@@ -753,10 +753,16 @@ static int csi_start(struct csi_priv *priv)
 
 	output_fi = &priv->frame_interval[priv->active_output_pad];
 
+	/* start upstream */
+	ret = v4l2_subdev_call(priv->src_sd, video, s_stream, 1);
+	ret = (ret && ret != -ENOIOCTLCMD) ? ret : 0;
+	if (ret)
+		return ret;
+
 	if (priv->dest == IPU_CSI_DEST_IDMAC) {
 		ret = csi_idmac_start(priv);
 		if (ret)
-			return ret;
+			goto stop_upstream;
 	}
 
 	ret = csi_setup(priv);
@@ -784,6 +790,8 @@ static int csi_start(struct csi_priv *priv)
 idmac_stop:
 	if (priv->dest == IPU_CSI_DEST_IDMAC)
 		csi_idmac_stop(priv);
+stop_upstream:
+	v4l2_subdev_call(priv->src_sd, video, s_stream, 0);
 	return ret;
 }
 
@@ -799,6 +807,9 @@ static void csi_stop(struct csi_priv *priv)
 	 */
 	ipu_csi_disable(priv->csi);
 
+	/* stop upstream */
+	v4l2_subdev_call(priv->src_sd, video, s_stream, 0);
+
 	if (priv->dest == IPU_CSI_DEST_IDMAC) {
 		csi_idmac_stop(priv);
 
@@ -966,23 +977,13 @@ static int csi_s_stream(struct v4l2_subdev *sd, int enable)
 		goto update_count;
 
 	if (enable) {
-		/* upstream must be started first, before starting CSI */
-		ret = v4l2_subdev_call(priv->src_sd, video, s_stream, 1);
-		ret = (ret && ret != -ENOIOCTLCMD) ? ret : 0;
-		if (ret)
-			goto out;
-
 		dev_dbg(priv->dev, "stream ON\n");
 		ret = csi_start(priv);
-		if (ret) {
-			v4l2_subdev_call(priv->src_sd, video, s_stream, 0);
+		if (ret)
 			goto out;
-		}
 	} else {
 		dev_dbg(priv->dev, "stream OFF\n");
-		/* CSI must be stopped first, then stop upstream */
 		csi_stop(priv);
-		v4l2_subdev_call(priv->src_sd, video, s_stream, 0);
 	}
 
 update_count: