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From: Julien Massot <julien.massot@collabora.com>
To: linux-media@vger.kernel.org,
	sakari.ailus@iki.fi
Cc: devicetree@vger.kernel.org,
	kernel@collabora.com,
	linux-kernel@vger.kernel.org,
	mchehab@kernel.org,
	robh+dt@kernel.org,
	krzysztof.kozlowski+dt@linaro.org,
	conor+dt@kernel.org,
	Julien Massot <julien.massot@collabora.com>
Subject: [PATCH v7 5/5] drivers: media: max96717: stop the csi receiver before the source
Date: Tue, 30 Apr 2024 15:19:31 +0200
Message-ID: <20240430131931.166012-6-julien.massot@collabora.com>
In-Reply-To: <20240430131931.166012-1-julien.massot@collabora.com>
References: <20240430131931.166012-1-julien.massot@collabora.com>
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Stopping the CSI source before stopping the serializer
CSI port may make the serializer not respond.
Then all the next writes to the device will fail.

max96717 1-0040: Error writing reg 0x0308: -121
max96717 1-0040: Error writing reg 0x0006: -121

Fix that by stopping the CSI receiver first and then CSI source.

Seen on max96717f revision 4.

Signed-off-by: Julien Massot <julien.massot@collabora.com>
---
 drivers/media/i2c/max96717.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/media/i2c/max96717.c b/drivers/media/i2c/max96717.c
index 1ea76f922bdb..499408837aef 100644
--- a/drivers/media/i2c/max96717.c
+++ b/drivers/media/i2c/max96717.c
@@ -384,24 +384,23 @@ static int max96717_disable_streams(struct v4l2_subdev *sd,
 {
 	struct max96717_priv *priv = sd_to_max96717(sd);
 	u64 sink_streams;
-	int ret;
+
+	/*
+	 * Stop the CSI receiver first then the source,
+	 * otherwise the device may become unresponsive
+	 * while holding the I2C bus low.
+	 */
+	priv->enabled_source_streams &= ~streams_mask;
+	if (!priv->enabled_source_streams)
+		max96717_start_csi(priv, false);
 
 	sink_streams = v4l2_subdev_state_xlate_streams(state,
 						       MAX96717_PAD_SOURCE,
 						       MAX96717_PAD_SINK,
 						       &streams_mask);
 
-	ret = v4l2_subdev_disable_streams(priv->source_sd, priv->source_sd_pad,
-					  sink_streams);
-	if (ret)
-		return ret;
-
-	priv->enabled_source_streams &= ~streams_mask;
-
-	if (!priv->enabled_source_streams)
-		max96717_start_csi(priv, false);
-
-	return 0;
+	return v4l2_subdev_disable_streams(priv->source_sd, priv->source_sd_pad,
+					   sink_streams);
 }
 
 static const struct v4l2_subdev_pad_ops max96717_pad_ops = {
-- 
2.44.0