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media: staging: imx: configure src_mux in csi_start

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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: 4a34ec8e47 ("[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>
This commit is contained in:
Michael Tretter
2025-11-07 11:34:34 +01:00
committed by Hans Verkuil
parent 9df2aaa648
commit ebeec2b000
1 changed files with 24 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

44
drivers/staging/media/imx/imx-media-csi.c
View File

@@ -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;
}