[PATCH v4 2/3] media: imx: csi: Stop upstream before disabling IDMA channel

[Steve Longerbeam]

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@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/staging/media/imx/imx-media-csi.c | 25 ++++++++++++-----------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 920e38885292..d851ca2497b4 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/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:
-- 
2.17.1