FAILED: patch "[PATCH] media: staging: imx: configure src_mux in csi_start" failed to apply to 6.18-stable tree

FAILED: patch "[PATCH] media: staging: imx: configure src_mux in csi_start" failed to apply to 6.18-stable tree

[gregkh]

The patch below does not apply to the 6.18-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y
git checkout FETCH_HEAD
git cherry-pick -x ebeec2b000a90cd8aae86d1931ff5ef23af8284e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051552-pasta-scariness-9d08@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ebeec2b000a90cd8aae86d1931ff5ef23af8284e Mon Sep 17 00:00:00 2001
From: Michael Tretter <m.tretter@pengutronix.de>
Date: Fri, 7 Nov 2025 11:34:34 +0100
Subject: [PATCH] media: staging: imx: configure src_mux in csi_start

After media_pipeline_start() was called, the media graph is assumed to
be validated. It won't be validated again if a second stream starts.

The imx-media-csi driver, however, changes hardware configuration in the
link_validate() callback. This can result in started streams with
misconfigured hardware.

In the concrete example, the ipu2_csi1 is driven by a parallel video
input. After the media pipeline has been started with this
configuration, a second stream is configured to use ipu1_csi0 with
MIPI-CSI input from imx6-mipi-csi2. This may require the reconfiguration
of ipu1_csi0 with ipu_set_csi_src_mux(). Since the media pipeline is
already running, link_validate won't be called, and the ipu1_csi0 won't
be reconfigured. The resulting video is broken, because the ipu1_csi0 is
misconfigured, but no error is reported.

Move ipu_set_csi_src_mux from csi_link_validate to csi_start to ensure
that input to ipu1_csi0 is configured correctly when starting the
stream. This is a local reconfiguration in ipu1_csi0 and is possible
while the media pipeline is running.

Since csi_start() is called with priv->lock already locked,
csi_set_src() must not lock priv->lock again. Thus, the mutex_lock() is
dropped.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Fixes: 4a34ec8e470c ("[media] media: imx: Add CSI subdev driver")
Cc: stable@vger.kernel.org
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index dc594b286f73..ef22a083f8eb 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -744,6 +744,28 @@ static int csi_setup(struct csi_priv *priv,
 	return 0;
 }
 
+static void csi_set_src(struct csi_priv *priv,
+			struct v4l2_mbus_config *mbus_cfg)
+{
+	bool is_csi2;
+
+	is_csi2 = !is_parallel_bus(mbus_cfg);
+	if (is_csi2) {
+		/*
+		 * NOTE! It seems the virtual channels from the mipi csi-2
+		 * receiver are used only for routing by the video mux's,
+		 * or for hard-wired routing to the CSI's. Once the stream
+		 * enters the CSI's however, they are treated internally
+		 * in the IPU as virtual channel 0.
+		 */
+		ipu_csi_set_mipi_datatype(priv->csi, 0,
+					  &priv->format_mbus[CSI_SINK_PAD]);
+	}
+
+	/* select either parallel or MIPI-CSI2 as input to CSI */
+	ipu_set_csi_src_mux(priv->ipu, priv->csi_id, is_csi2);
+}
+
 static int csi_start(struct csi_priv *priv)
 {
 	struct v4l2_mbus_config mbus_cfg = { .type = 0 };
@@ -760,6 +782,8 @@ static int csi_start(struct csi_priv *priv)
 	input_fi = &priv->frame_interval[CSI_SINK_PAD];
 	output_fi = &priv->frame_interval[priv->active_output_pad];
 
+	csi_set_src(priv, &mbus_cfg);
+
 	/* start upstream */
 	ret = v4l2_subdev_call(priv->src_sd, video, s_stream, 1);
 	ret = (ret && ret != -ENOIOCTLCMD) ? ret : 0;
@@ -1130,7 +1154,6 @@ static int csi_link_validate(struct v4l2_subdev *sd,
 {
 	struct csi_priv *priv = v4l2_get_subdevdata(sd);
 	struct v4l2_mbus_config mbus_cfg = { .type = 0 };
-	bool is_csi2;
 	int ret;
 
 	ret = v4l2_subdev_link_validate_default(sd, link,
@@ -1145,25 +1168,6 @@ static int csi_link_validate(struct v4l2_subdev *sd,
 		return ret;
 	}
 
-	mutex_lock(&priv->lock);
-
-	is_csi2 = !is_parallel_bus(&mbus_cfg);
-	if (is_csi2) {
-		/*
-		 * NOTE! It seems the virtual channels from the mipi csi-2
-		 * receiver are used only for routing by the video mux's,
-		 * or for hard-wired routing to the CSI's. Once the stream
-		 * enters the CSI's however, they are treated internally
-		 * in the IPU as virtual channel 0.
-		 */
-		ipu_csi_set_mipi_datatype(priv->csi, 0,
-					  &priv->format_mbus[CSI_SINK_PAD]);
-	}
-
-	/* select either parallel or MIPI-CSI2 as input to CSI */
-	ipu_set_csi_src_mux(priv->ipu, priv->csi_id, is_csi2);
-
-	mutex_unlock(&priv->lock);
 	return ret;
 }
 

[PATCH 6.18.y] media: staging: imx: configure src_mux in csi_start

[Michael Tretter]

After media_pipeline_start() was called, the media graph is assumed to
be validated. It won't be validated again if a second stream starts.

The imx-media-csi driver, however, changes hardware configuration in the
link_validate() callback. This can result in started streams with
misconfigured hardware.

In the concrete example, the ipu2_csi1 is driven by a parallel video
input. After the media pipeline has been started with this
configuration, a second stream is configured to use ipu1_csi0 with
MIPI-CSI input from imx6-mipi-csi2. This may require the reconfiguration
of ipu1_csi0 with ipu_set_csi_src_mux(). Since the media pipeline is
already running, link_validate won't be called, and the ipu1_csi0 won't
be reconfigured. The resulting video is broken, because the ipu1_csi0 is
misconfigured, but no error is reported.

Move ipu_set_csi_src_mux from csi_link_validate to csi_start to ensure
that input to ipu1_csi0 is configured correctly when starting the
stream. This is a local reconfiguration in ipu1_csi0 and is possible
while the media pipeline is running.

Since csi_start() is called with priv->lock already locked,
csi_set_src() must not lock priv->lock again. Thus, the mutex_lock() is
dropped.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Fixes: 4a34ec8e470c ("[media] media: imx: Add CSI subdev driver")
Cc: stable@vger.kernel.org
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
(cherry picked from commit ebeec2b000a90cd8aae86d1931ff5ef23af8284e)
---
 drivers/staging/media/imx/imx-media-csi.c | 44 ++++++++++++-----------
 1 file changed, 24 insertions(+), 20 deletions(-)

diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c
index 55a7d8f38465..1bc644f73a9d 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c
@@ -744,6 +744,28 @@ static int csi_setup(struct csi_priv *priv,
 	return 0;
 }
 
+static void csi_set_src(struct csi_priv *priv,
+			struct v4l2_mbus_config *mbus_cfg)
+{
+	bool is_csi2;
+
+	is_csi2 = !is_parallel_bus(mbus_cfg);
+	if (is_csi2) {
+		/*
+		 * NOTE! It seems the virtual channels from the mipi csi-2
+		 * receiver are used only for routing by the video mux's,
+		 * or for hard-wired routing to the CSI's. Once the stream
+		 * enters the CSI's however, they are treated internally
+		 * in the IPU as virtual channel 0.
+		 */
+		ipu_csi_set_mipi_datatype(priv->csi, 0,
+					  &priv->format_mbus[CSI_SINK_PAD]);
+	}
+
+	/* select either parallel or MIPI-CSI2 as input to CSI */
+	ipu_set_csi_src_mux(priv->ipu, priv->csi_id, is_csi2);
+}
+
 static int csi_start(struct csi_priv *priv)
 {
 	struct v4l2_mbus_config mbus_cfg = { .type = 0 };
@@ -760,6 +782,8 @@ static int csi_start(struct csi_priv *priv)
 	input_fi = &priv->frame_interval[CSI_SINK_PAD];
 	output_fi = &priv->frame_interval[priv->active_output_pad];
 
+	csi_set_src(priv, &mbus_cfg);
+
 	/* start upstream */
 	ret = v4l2_subdev_call(priv->src_sd, video, s_stream, 1);
 	ret = (ret && ret != -ENOIOCTLCMD) ? ret : 0;
@@ -1130,7 +1154,6 @@ static int csi_link_validate(struct v4l2_subdev *sd,
 {
 	struct csi_priv *priv = v4l2_get_subdevdata(sd);
 	struct v4l2_mbus_config mbus_cfg = { .type = 0 };
-	bool is_csi2;
 	int ret;
 
 	ret = v4l2_subdev_link_validate_default(sd, link,
@@ -1145,25 +1168,6 @@ static int csi_link_validate(struct v4l2_subdev *sd,
 		return ret;
 	}
 
-	mutex_lock(&priv->lock);
-
-	is_csi2 = !is_parallel_bus(&mbus_cfg);
-	if (is_csi2) {
-		/*
-		 * NOTE! It seems the virtual channels from the mipi csi-2
-		 * receiver are used only for routing by the video mux's,
-		 * or for hard-wired routing to the CSI's. Once the stream
-		 * enters the CSI's however, they are treated internally
-		 * in the IPU as virtual channel 0.
-		 */
-		ipu_csi_set_mipi_datatype(priv->csi, 0,
-					  &priv->format_mbus[CSI_SINK_PAD]);
-	}
-
-	/* select either parallel or MIPI-CSI2 as input to CSI */
-	ipu_set_csi_src_mux(priv->ipu, priv->csi_id, is_csi2);
-
-	mutex_unlock(&priv->lock);
 	return ret;
 }
 
-- 
2.47.3

Re: [PATCH 6.18.y] media: staging: imx: configure src_mux in csi_start

[Sasha Levin]

On Tue, May 19, 2026 at 04:14:36PM +0200, Michael Tretter wrote:
> After media_pipeline_start() was called, the media graph is assumed to
> be validated. It won't be validated again if a second stream starts.
>
> The imx-media-csi driver, however, changes hardware configuration in the
> link_validate() callback. This can result in started streams with
> misconfigured hardware.
[...]
> Move ipu_set_csi_src_mux from csi_link_validate to csi_start to ensure
> that input to ipu1_csi0 is configured correctly when starting the
> stream.

Queued for 6.18, thanks.

For completeness: this fix also applies to 7.0 (it was missing there
too). I queued the upstream commit as a cherry-pick into the 7.0 queue
in this run as well.

--
Thanks,
Sasha