[media] media: imx: Drop warning upon multiple S_STREAM disable calls

Calling S_STREAM OFF multiple times on a video device is valid, although
dubious, practice. Instead of warning about it and setting stream count
lower than zero, just ignore the subsequent S_STREAM calls and correct
the stream count to zero.
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/staging/media/imx/imx-ic-prp.c

@@ -391,7 +391,8 @@ static int prp_s_stream(struct v4l2_subdev *sd, int enable)
 
 update_count:
 	priv->stream_count += enable ? 1 : -1;
-	WARN_ON(priv->stream_count < 0);
+	if (priv->stream_count < 0)
+		priv->stream_count = 0;
 out:
 	mutex_unlock(&priv->lock);
 	return ret;

drivers/staging/media/imx/imx-ic-prpencvf.c

@@ -1140,7 +1140,8 @@ static int prp_s_stream(struct v4l2_subdev *sd, int enable)
 
 update_count:
 	priv->stream_count += enable ? 1 : -1;
-	WARN_ON(priv->stream_count < 0);
+	if (priv->stream_count < 0)
+		priv->stream_count = 0;
 out:
 	mutex_unlock(&priv->lock);
 	return ret;

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

@@ -864,7 +864,8 @@ static int csi_s_stream(struct v4l2_subdev *sd, int enable)
 
 update_count:
 	priv->stream_count += enable ? 1 : -1;
-	WARN_ON(priv->stream_count < 0);
+	if (priv->stream_count < 0)
+		priv->stream_count = 0;
 out:
 	mutex_unlock(&priv->lock);
 	return ret;

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

@@ -536,7 +536,8 @@ static int vdic_s_stream(struct v4l2_subdev *sd, int enable)
 
 update_count:
 	priv->stream_count += enable ? 1 : -1;
-	WARN_ON(priv->stream_count < 0);
+	if (priv->stream_count < 0)
+		priv->stream_count = 0;
 out:
 	mutex_unlock(&priv->lock);
 	return ret;

drivers/staging/media/imx/imx6-mipi-csi2.c

@@ -397,7 +397,8 @@ static int csi2_s_stream(struct v4l2_subdev *sd, int enable)
 
 update_count:
 	csi2->stream_count += enable ? 1 : -1;
-	WARN_ON(csi2->stream_count < 0);
+	if (csi2->stream_count < 0)
+		csi2->stream_count = 0;
 out:
 	mutex_unlock(&csi2->lock);
 	return ret;