[PATCH v6 04/11] media: rcar-csi2: Move {enable|disable}_streams() calls

[Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>]

With multiple streams the operation to enable the CSI-2 hardware and to
call {enable|disable}_streams() on upstream subdev will need to be
handled separately.

Prepare for that by moving {enable|disable}_streams() calls out from
rcsi2_start() and rcsi2_stop().

As the error recovery in rcsi2_irq_thread() relies on rcsi2_start() and
rcsi2_stop(), we need to modify rcsi2_irq_thread() accordingly.

On Gen3, a side effect of this change is that if the sink side devices
call .enable_streams() on rcar-csi2 multiple times, the second call will
fail. This is because we always use stream ID 0, so the second call
would attempt to enable the same stream again, leading to an error. In
other words, a normal single-stream setup continues to work, but trying
to use the current driver's custom VC based routing will fail.

On Gen4, this doesn't matter as the rcar-isp behaves in a similar way as
described above, and thus rcar-csi2 will only get a single
.enable_streams() call.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
---
 drivers/media/platform/renesas/rcar-csi2.c | 59 ++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 12 deletions(-)

diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
index 7305cc4a04cb..f5d8b06dff51 100644
--- a/drivers/media/platform/renesas/rcar-csi2.c
+++ b/drivers/media/platform/renesas/rcar-csi2.c
@@ -1822,20 +1822,12 @@ static int rcsi2_start(struct rcar_csi2 *priv, struct v4l2_subdev_state *state)
 		return ret;
 	}
 
-	ret = v4l2_subdev_enable_streams(priv->remote, priv->remote_pad,
-					 BIT_ULL(0));
-	if (ret) {
-		rcsi2_enter_standby(priv);
-		return ret;
-	}
-
 	return 0;
 }
 
 static void rcsi2_stop(struct rcar_csi2 *priv)
 {
 	rcsi2_enter_standby(priv);
-	v4l2_subdev_disable_streams(priv->remote, priv->remote_pad, BIT_ULL(0));
 }
 
 static int rcsi2_enable_streams(struct v4l2_subdev *sd,
@@ -1857,6 +1849,14 @@ static int rcsi2_enable_streams(struct v4l2_subdev *sd,
 			return ret;
 	}
 
+	ret = v4l2_subdev_enable_streams(priv->remote, priv->remote_pad,
+					 BIT_ULL(0));
+	if (ret) {
+		if (priv->stream_count == 0)
+			rcsi2_stop(priv);
+		return ret;
+	}
+
 	priv->stream_count += 1;
 
 	return ret;
@@ -1867,7 +1867,7 @@ static int rcsi2_disable_streams(struct v4l2_subdev *sd,
 				 u32 source_pad, u64 source_streams_mask)
 {
 	struct rcar_csi2 *priv = sd_to_csi2(sd);
-	int ret = 0;
+	int ret;
 
 	if (source_streams_mask != 1)
 		return -EINVAL;
@@ -1878,9 +1878,14 @@ static int rcsi2_disable_streams(struct v4l2_subdev *sd,
 	if (priv->stream_count == 1)
 		rcsi2_stop(priv);
 
+	ret = v4l2_subdev_disable_streams(priv->remote, priv->remote_pad,
+					  BIT_ULL(0));
+	if (ret)
+		return ret;
+
 	priv->stream_count -= 1;
 
-	return ret;
+	return 0;
 }
 
 static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
@@ -1971,14 +1976,44 @@ static irqreturn_t rcsi2_irq_thread(int irq, void *data)
 {
 	struct v4l2_subdev_state *state;
 	struct rcar_csi2 *priv = data;
+	int ret;
 
 	state = v4l2_subdev_lock_and_get_active_state(&priv->subdev);
 
+	if (priv->stream_count == 0)
+		goto out;
+
 	rcsi2_stop(priv);
+
+	ret = v4l2_subdev_disable_streams(priv->remote, priv->remote_pad,
+					  BIT_ULL(0));
+	if (ret) {
+		dev_warn(priv->dev,
+			 "Error recovery: failed to disable streams: %d\n",
+			 ret);
+		goto out;
+	}
+
 	usleep_range(1000, 2000);
-	if (rcsi2_start(priv, state))
-		dev_warn(priv->dev, "Failed to restart CSI-2 receiver\n");
 
+	ret = rcsi2_start(priv, state);
+	if (ret) {
+		dev_warn(priv->dev,
+			 "Error recovery: failed to start CSI-2 receiver: %d\n",
+			 ret);
+		goto out;
+	}
+
+	ret = v4l2_subdev_enable_streams(priv->remote, priv->remote_pad,
+					 BIT_ULL(0));
+	if (ret) {
+		dev_warn(priv->dev,
+			 "Error recovery: failed to start streams: %d\n",
+			 ret);
+		goto out;
+	}
+
+out:
 	v4l2_subdev_unlock_state(state);
 
 	return IRQ_HANDLED;

-- 
2.43.0