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>

Request the upstream mbus_config in csi_start, which starts the stream,
instead of caching it in link_validate.

This allows to get rid of the mbus_cfg field in the struct csi_priv and
avoids state in the driver.

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

Applied checkpatch.pl recommendations:
- corrected whitespace
- fixed line length
- adjusted indentation

Signed-off-by: vivek yadav <y9.vivek@gmail.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

Adhering to Linux kernel coding style guidelines (Chapter 3: Indentation).

Signed-off-by: Ayush Kumar <ayushkr0s@gmail.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>

Use devm_platform_ioremap_resource() simplify code. No functional change.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260116-stage-csi2-cleanup-v2-5-a56e9cb25196@nxp.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

Use devm_mutex_init() to simplify the code. No functional change.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20260116-stage-csi2-cleanup-v2-2-a56e9cb25196@nxp.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

Replace spaces with tabs to align register value definitions, making it
easier to add new entries and maintain consistent formatting.

Also use a space between the type and field in struct csi2_dev.

No functional change.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patch.msgid.link/20260116-stage-csi2-cleanup-v2-1-a56e9cb25196@nxp.com
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

The v4l2_m2m_buf_copy_metadata() function takes a boolean
copy_frame_flags argument. When true, it causes the function to copy the
V4L2_BUF_FLAG_KEYFRAME, V4L2_BUF_FLAG_BFRAME and V4L2_BUF_FLAG_PFRAME
flags from the output buffer to the capture buffer.

There is no use cases in any upstream driver for copying the flags.
KEY/P/B frames are properties of the bitstream buffer in some formats.
Once decoded, this is no longer a property of the video frame and should
be discarded.

It was considered useful to know if an uncompressed frame was decoded
from a KEY/P/B compressed frame, and to preserve that information if
that same uncompressed frame was passed through another M2M device (e.g.
a scaler). However, the V4L2 documentation makes it clear that the flags
are meant for compressed frames only.

Drop the copy_frame_flags argument from v4l2_m2m_buf_copy_metadata().
The change to drivers was performed with the following Coccinelle
semantic patch:

@@
expression src;
expression dst;
expression flag;
@@
-       v4l2_m2m_buf_copy_metadata(src, dst, flag);
+       v4l2_m2m_buf_copy_metadata(src, dst);

include/media/v4l2-mem2mem.h and drivers/media/v4l2-core/v4l2-mem2mem.c
have been updated manually.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>