Hi,
Media drivers need to iterate through the pipeline and call .s_stream()
callbacks in the subdevices.
Instead of repeating code, add helpers for this.
These helpers will go walk through the pipeline only visiting entities
that participates in the stream, i.e. it follow link from sink to source
(and not the opposite).
Which means that in a topology like this https://bit.ly/3b2MxjI
calling v4l2_pipeline_stream_enable() from rkisp1_mainpath won't call
.s_stream(true) for rkisp1_resizer_selfpath.
stream_count variable was added in v4l2_subdevice to handle nested calls
to the helpers.
This is useful when the driver allows streaming from more then one
capture device sharing subdevices.
This patch came from the error I was facing when multistreaming from
rkisp1 driver, where stopping one capture would call s_stream(false) in
the pipeline, causing a stall in the second capture device.
Also, the vimc patch https://patchwork.kernel.org/patch/10948833/ won't
be required with this patchset.
This patchset was tested on rkisp1 and vimc drivers.
Other cleanup might be possible (but I won't add in this patchset as I
don't have the hw to test):
https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/omap3isp/isp.c#n697
https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/qcom/camss/camss-video.c#n430
https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/stm32/stm32-dcmi.c#n680
https://git.linuxtv.org/media_tree.git/tree/drivers/media/platform/xilinx/xilinx-dma.c#n97
Overview of patches:
====================
Patch 1/4 adds a new iterator function to follow links from sink to
source only.
Path 2/4 adds the helpers in v4l2-common.c, allowing nested calls by
adding stream_count in the subdevice struct.
Patch 3/4 cleanup rkisp1 driver to use the helpers.
Patch 4/4 cleanup vimc driver to use the helpers.
Helen Koike (4):
media: mc-entity.c: add media_graph_walk_next_stream()
media: v4l2-common: add helper functions to call s_stream() callbacks
media: staging: rkisp1: use v4l2_pipeline_stream_{enable,disable}
helpers
media: vimc: use v4l2_pipeline_stream_{enable,disable} helpers
drivers/media/mc/mc-entity.c | 34 ++++++-
drivers/media/platform/vimc/vimc-capture.c | 28 ++++--
drivers/media/platform/vimc/vimc-streamer.c | 49 +--------
drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++
drivers/staging/media/rkisp1/rkisp1-capture.c | 74 +-------------
include/media/media-entity.h | 15 +++
include/media/v4l2-common.h | 30 ++++++
include/media/v4l2-subdev.h | 2 +
8 files changed, 204 insertions(+), 127 deletions(-)
--
2.25.0
Use v4l2_pipeline_stream_{enable,disable} to call .s_stream() subdevice
callbacks through the pipeline.
Tested by streaming on RockPi4 with imx219.
Signed-off-by: Helen Koike <[email protected]>
---
drivers/staging/media/rkisp1/rkisp1-capture.c | 74 +------------------
1 file changed, 4 insertions(+), 70 deletions(-)
diff --git a/drivers/staging/media/rkisp1/rkisp1-capture.c b/drivers/staging/media/rkisp1/rkisp1-capture.c
index 24fe6a7888aa..9e1f3e022016 100644
--- a/drivers/staging/media/rkisp1/rkisp1-capture.c
+++ b/drivers/staging/media/rkisp1/rkisp1-capture.c
@@ -838,71 +838,6 @@ static void rkisp1_return_all_buffers(struct rkisp1_capture *cap,
spin_unlock_irqrestore(&cap->buf.lock, flags);
}
-/*
- * rkisp1_pipeline_sink_walk - Walk through the pipeline and call cb
- * @from: entity at which to start pipeline walk
- * @until: entity at which to stop pipeline walk
- *
- * Walk the entities chain starting at the pipeline video node and stop
- * all subdevices in the chain.
- *
- * If the until argument isn't NULL, stop the pipeline walk when reaching the
- * until entity. This is used to disable a partially started pipeline due to a
- * subdev start error.
- */
-static int rkisp1_pipeline_sink_walk(struct media_entity *from,
- struct media_entity *until,
- int (*cb)(struct media_entity *from,
- struct media_entity *curr))
-{
- struct media_entity *entity = from;
- struct media_pad *pad;
- unsigned int i;
- int ret;
-
- while (1) {
- pad = NULL;
- /* Find remote source pad */
- for (i = 0; i < entity->num_pads; i++) {
- struct media_pad *spad = &entity->pads[i];
-
- if (!(spad->flags & MEDIA_PAD_FL_SINK))
- continue;
- pad = media_entity_remote_pad(spad);
- if (pad && is_media_entity_v4l2_subdev(pad->entity))
- break;
- }
- if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
- break;
-
- entity = pad->entity;
- if (entity == until)
- break;
-
- ret = cb(from, entity);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
-static int rkisp1_pipeline_disable_cb(struct media_entity *from,
- struct media_entity *curr)
-{
- struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
-
- return v4l2_subdev_call(sd, video, s_stream, false);
-}
-
-static int rkisp1_pipeline_enable_cb(struct media_entity *from,
- struct media_entity *curr)
-{
- struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(curr);
-
- return v4l2_subdev_call(sd, video, s_stream, true);
-}
-
static void rkisp1_stream_stop(struct rkisp1_capture *cap)
{
int ret;
@@ -929,8 +864,8 @@ static void rkisp1_vb2_stop_streaming(struct vb2_queue *queue)
rkisp1_stream_stop(cap);
media_pipeline_stop(&node->vdev.entity);
- ret = rkisp1_pipeline_sink_walk(&node->vdev.entity, NULL,
- rkisp1_pipeline_disable_cb);
+ ret = v4l2_pipeline_stream_disable(&node->vdev.entity,
+ &cap->rkisp1->pipe);
if (ret)
dev_err(rkisp1->dev,
"pipeline stream-off failed error:%d\n", ret);
@@ -1005,8 +940,7 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
rkisp1_stream_start(cap);
/* start sub-devices */
- ret = rkisp1_pipeline_sink_walk(entity, NULL,
- rkisp1_pipeline_enable_cb);
+ ret = v4l2_pipeline_stream_enable(entity, &cap->rkisp1->pipe);
if (ret)
goto err_stop_stream;
@@ -1019,7 +953,7 @@ rkisp1_vb2_start_streaming(struct vb2_queue *queue, unsigned int count)
return 0;
err_pipe_disable:
- rkisp1_pipeline_sink_walk(entity, NULL, rkisp1_pipeline_disable_cb);
+ v4l2_pipeline_stream_disable(entity, &cap->rkisp1->pipe);
err_stop_stream:
rkisp1_stream_stop(cap);
v4l2_pipeline_pm_put(entity);
--
2.25.0
Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
through the subdevices in a given stream (i.e following links from sink
to source) and call .s_stream() callback.
Add stream_count on the subdevice object for simultaneous streaming from
different video devices which shares subdevices.
Prevent calling .s_stream(true) if it was already called previously by
another stream.
Prevent calling .s_stream(false) from one stream when there are still
others active.
Signed-off-by: Helen Koike <[email protected]>
---
drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
include/media/v4l2-common.h | 30 ++++++++
include/media/v4l2-subdev.h | 2 +
3 files changed, 131 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index d0e5ebc736f9..6a5a3d2c282e 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -441,3 +441,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
return 0;
}
EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
+
+int v4l2_pipeline_stream_disable(struct media_entity *entity,
+ struct media_pipeline *pipe)
+{
+ struct media_device *mdev = entity->graph_obj.mdev;
+ int ret = 0;
+
+ mutex_lock(&mdev->graph_mutex);
+
+ if (!pipe->streaming_count) {
+ ret = media_graph_walk_init(&pipe->graph, mdev);
+ if (ret) {
+ mutex_unlock(&mdev->graph_mutex);
+ return ret;
+ }
+ }
+
+ media_graph_walk_start(&pipe->graph, entity);
+
+ while ((entity = media_graph_walk_next_stream(&pipe->graph))) {
+ struct v4l2_subdev *sd;
+
+ if (!is_media_entity_v4l2_subdev(entity))
+ continue;
+
+ sd = media_entity_to_v4l2_subdev(entity);
+ if (!sd->stream_count || --sd->stream_count)
+ continue;
+
+ ret = v4l2_subdev_call(sd, video, s_stream, false);
+ if (ret && ret != -ENOIOCTLCMD)
+ dev_dbg(mdev->dev,
+ "couldn't disable stream for subdevice '%s'\n",
+ entity->name);
+ break;
+ }
+
+ dev_dbg(mdev->dev,
+ "stream disabled for subdevice '%s'\n", entity->name);
+ }
+
+ if (!pipe->streaming_count)
+ media_graph_walk_cleanup(&pipe->graph);
+
+ mutex_unlock(&mdev->graph_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
+
+__must_check int v4l2_pipeline_stream_enable(struct media_entity *entity,
+ struct media_pipeline *pipe)
+{
+ struct media_device *mdev = entity->graph_obj.mdev;
+ int ret = 0;
+
+ mutex_lock(&mdev->graph_mutex);
+
+ if (!pipe->streaming_count) {
+ ret = media_graph_walk_init(&pipe->graph, mdev);
+ if (ret) {
+ mutex_unlock(&mdev->graph_mutex);
+ return ret;
+ }
+ }
+
+ media_graph_walk_start(&pipe->graph, entity);
+
+ while ((entity = media_graph_walk_next_stream(&pipe->graph))) {
+ struct v4l2_subdev *sd;
+
+ if (!is_media_entity_v4l2_subdev(entity))
+ continue;
+
+ sd = media_entity_to_v4l2_subdev(entity);
+ if (sd->stream_count++)
+ continue;
+
+ ret = v4l2_subdev_call(sd, video, s_stream, true);
+ if (ret && ret != -ENOIOCTLCMD)
+ dev_dbg(mdev->dev,
+ "couldn't enable stream for subdevice '%s'\n",
+ entity->name);
+ v4l2_pipeline_stream_disable(entity, pipe);
+ break;
+ }
+
+ dev_dbg(mdev->dev,
+ "stream enabled for subdevice '%s'\n", entity->name);
+ }
+
+ if (!pipe->streaming_count)
+ media_graph_walk_cleanup(&pipe->graph);
+
+ mutex_unlock(&mdev->graph_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 150ee16ebd81..46c0857d07c4 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -519,6 +519,36 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
u32 width, u32 height);
+/**
+ * media_pipeline_stop - Mark a pipeline as not streaming
+ * @entity: Starting entity
+ * @pipe: Media pipeline to iterate through the topology
+ *
+ * Call .s_stream(false) callback in all the subdevices participating in the
+ * stream, i.e. following links from sink to source.
+ *
+ * If multiple calls to v4l2_pipeline_stream_enable() have been made, the
+ * same number of calls to this function are required.
+ */
+int v4l2_pipeline_stream_disable(struct media_entity *entity,
+ struct media_pipeline *pipe);
+
+/**
+ * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
+ * @entity: Starting entity
+ * @pipe: Media pipeline to iterate through the topology
+ *
+ * Call .s_stream(true) callback in all the subdevices participating in the
+ * stream, i.e. following links from sink to source.
+ *
+ * Calls to this function can be nested, in which case the same number of
+ * v4l2_pipeline_stream_disable() calls will be required to stop streaming.
+ * The pipeline pointer must be identical for all nested calls to
+ * v4l2_pipeline_stream_enable().
+ */
+__must_check int v4l2_pipeline_stream_enable(struct media_entity *entity,
+ struct media_pipeline *pipe);
+
static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf)
{
/*
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index a4848de59852..20f913a9f70c 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -838,6 +838,7 @@ struct v4l2_subdev_platform_data {
* @subdev_notifier: A sub-device notifier implicitly registered for the sub-
* device using v4l2_device_register_sensor_subdev().
* @pdata: common part of subdevice platform data
+ * @stream_count: Stream count for the subdevice.
*
* Each instance of a subdev driver should create this struct, either
* stand-alone or embedded in a larger struct.
@@ -869,6 +870,7 @@ struct v4l2_subdev {
struct v4l2_async_notifier *notifier;
struct v4l2_async_notifier *subdev_notifier;
struct v4l2_subdev_platform_data *pdata;
+ unsigned int stream_count;
};
--
2.25.0
Use v4l2_pipeline_stream_{enable,disable} to call .s_stream() subdevice
callbacks through the pipeline.
Tested streaming works with:
media-ctl -d /dev/media0 -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]'
media-ctl -d /dev/media0 -V '"Scaler":0[fmt:RGB888_1X24/640x480]'
media-ctl -d /dev/media0 -V '"Scaler":0[crop:(100,50)/400x150]'
media-ctl -d /dev/media0 -V '"Scaler":1[fmt:RGB888_1X24/1920x1440]'
v4l2-ctl -d /dev/video2 -v width=1200,height=450
v4l2-ctl -d /dev/video0 -v pixelformat=BA81
v4l2-ctl -d /dev/video1 -v pixelformat=BA81
v4l2-ctl --stream-mmap --stream-count=10 -d /dev/video2 --stream-to=/tmp/test.raw
Signed-off-by: Helen Koike <[email protected]>
---
drivers/media/platform/vimc/vimc-capture.c | 28 +++++++-----
drivers/media/platform/vimc/vimc-streamer.c | 49 +++------------------
2 files changed, 23 insertions(+), 54 deletions(-)
diff --git a/drivers/media/platform/vimc/vimc-capture.c b/drivers/media/platform/vimc/vimc-capture.c
index 23e740c1c5c0..f65d59728d8f 100644
--- a/drivers/media/platform/vimc/vimc-capture.c
+++ b/drivers/media/platform/vimc/vimc-capture.c
@@ -233,21 +233,27 @@ static int vimc_cap_start_streaming(struct vb2_queue *vq, unsigned int count)
vcap->sequence = 0;
- /* Start the media pipeline */
ret = media_pipeline_start(entity, &vcap->stream.pipe);
- if (ret) {
- vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
- return ret;
- }
+ if (ret)
+ goto err_return_all_buffers;
+
+ ret = v4l2_pipeline_stream_enable(entity, &vcap->stream.pipe);
+ if (ret)
+ goto err_stop_media_pipe;
ret = vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 1);
- if (ret) {
- media_pipeline_stop(entity);
- vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
- return ret;
- }
+ if (ret)
+ goto err_stop_stream;
return 0;
+
+err_stop_stream:
+ v4l2_pipeline_stream_disable(entity, &vcap->stream.pipe);
+err_stop_media_pipe:
+ media_pipeline_stop(entity);
+err_return_all_buffers:
+ vimc_cap_return_all_buffers(vcap, VB2_BUF_STATE_QUEUED);
+ return ret;
}
/*
@@ -260,6 +266,8 @@ static void vimc_cap_stop_streaming(struct vb2_queue *vq)
vimc_streamer_s_stream(&vcap->stream, &vcap->ved, 0);
+ v4l2_pipeline_stream_disable(&vcap->vdev.entity, &vcap->stream.pipe);
+
/* Stop the media pipeline */
media_pipeline_stop(&vcap->vdev.entity);
diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c
index 65feb3c596db..c0085f4695c2 100644
--- a/drivers/media/platform/vimc/vimc-streamer.c
+++ b/drivers/media/platform/vimc/vimc-streamer.c
@@ -36,33 +36,6 @@ static struct media_entity *vimc_get_source_entity(struct media_entity *ent)
return NULL;
}
-/**
- * vimc_streamer_pipeline_terminate - Disable stream in all ved in stream
- *
- * @stream: the pointer to the stream structure with the pipeline to be
- * disabled.
- *
- * Calls s_stream to disable the stream in each entity of the pipeline
- *
- */
-static void vimc_streamer_pipeline_terminate(struct vimc_stream *stream)
-{
- struct vimc_ent_device *ved;
- struct v4l2_subdev *sd;
-
- while (stream->pipe_size) {
- stream->pipe_size--;
- ved = stream->ved_pipeline[stream->pipe_size];
- stream->ved_pipeline[stream->pipe_size] = NULL;
-
- if (!is_media_entity_v4l2_subdev(ved->ent))
- continue;
-
- sd = media_entity_to_v4l2_subdev(ved->ent);
- v4l2_subdev_call(sd, video, s_stream, 0);
- }
-}
-
/**
* vimc_streamer_pipeline_init - Initializes the stream structure
*
@@ -82,27 +55,15 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
struct media_entity *entity;
struct video_device *vdev;
struct v4l2_subdev *sd;
- int ret = 0;
stream->pipe_size = 0;
while (stream->pipe_size < VIMC_STREAMER_PIPELINE_MAX_SIZE) {
if (!ved) {
- vimc_streamer_pipeline_terminate(stream);
+ stream->pipe_size = 0;
return -EINVAL;
}
stream->ved_pipeline[stream->pipe_size++] = ved;
- if (is_media_entity_v4l2_subdev(ved->ent)) {
- sd = media_entity_to_v4l2_subdev(ved->ent);
- ret = v4l2_subdev_call(sd, video, s_stream, 1);
- if (ret && ret != -ENOIOCTLCMD) {
- dev_err(ved->dev, "subdev_call error %s\n",
- ved->ent->name);
- vimc_streamer_pipeline_terminate(stream);
- return ret;
- }
- }
-
entity = vimc_get_source_entity(ved->ent);
/* Check if the end of the pipeline was reached */
if (!entity) {
@@ -111,7 +72,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
dev_err(ved->dev,
"first entity in the pipe '%s' is not a source\n",
ved->ent->name);
- vimc_streamer_pipeline_terminate(stream);
+ stream->pipe_size = 0;
return -EPIPE;
}
return 0;
@@ -129,7 +90,7 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream,
}
}
- vimc_streamer_pipeline_terminate(stream);
+ stream->pipe_size = 0;
return -EINVAL;
}
@@ -210,7 +171,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
if (IS_ERR(stream->kthread)) {
ret = PTR_ERR(stream->kthread);
dev_err(ved->dev, "kthread_run failed with %d\n", ret);
- vimc_streamer_pipeline_terminate(stream);
+ stream->pipe_size = 0;
stream->kthread = NULL;
return ret;
}
@@ -231,7 +192,7 @@ int vimc_streamer_s_stream(struct vimc_stream *stream,
stream->kthread = NULL;
- vimc_streamer_pipeline_terminate(stream);
+ stream->pipe_size = 0;
}
return 0;
--
2.25.0
On 3/16/20 4:33 PM, Helen Koike wrote:
> Add v4l2_pipeline_stream_{enable,disable} helper functions to iterate
> through the subdevices in a given stream (i.e following links from sink
> to source) and call .s_stream() callback.
>
> Add stream_count on the subdevice object for simultaneous streaming from
> different video devices which shares subdevices.
>
> Prevent calling .s_stream(true) if it was already called previously by
> another stream.
>
> Prevent calling .s_stream(false) from one stream when there are still
> others active.
>
> Signed-off-by: Helen Koike <[email protected]>
> ---
>
> drivers/media/v4l2-core/v4l2-common.c | 99 +++++++++++++++++++++++++++
> include/media/v4l2-common.h | 30 ++++++++
> include/media/v4l2-subdev.h | 2 +
> 3 files changed, 131 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index d0e5ebc736f9..6a5a3d2c282e 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -441,3 +441,102 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
> return 0;
> }
> EXPORT_SYMBOL_GPL(v4l2_fill_pixfmt);
> +
> +int v4l2_pipeline_stream_disable(struct media_entity *entity,
> + struct media_pipeline *pipe)
> +{
> + struct media_device *mdev = entity->graph_obj.mdev;
> + int ret = 0;
> +
> + mutex_lock(&mdev->graph_mutex);
> +
> + if (!pipe->streaming_count) {
> + ret = media_graph_walk_init(&pipe->graph, mdev);
> + if (ret) {
> + mutex_unlock(&mdev->graph_mutex);
> + return ret;
> + }
> + }
> +
> + media_graph_walk_start(&pipe->graph, entity);
> +
> + while ((entity = media_graph_walk_next_stream(&pipe->graph))) {
> + struct v4l2_subdev *sd;
> +
> + if (!is_media_entity_v4l2_subdev(entity))
> + continue;
> +
> + sd = media_entity_to_v4l2_subdev(entity);
> + if (!sd->stream_count || --sd->stream_count)
> + continue;
> +
> + ret = v4l2_subdev_call(sd, video, s_stream, false);
> + if (ret && ret != -ENOIOCTLCMD)
argh..., there is a missing open curly braces here (skipped when I added the check
for -ENOIOCTLCMD), sorry about that (/me embarrassed).
Fixed version can be found here https://gitlab.collabora.com/koike/linux/tree/v4l2/s_stream
I'll submit v2 after having your comments.
> + dev_dbg(mdev->dev,
> + "couldn't disable stream for subdevice '%s'\n",
> + entity->name);
> + break;
> + }
> +
> + dev_dbg(mdev->dev,
> + "stream disabled for subdevice '%s'\n", entity->name);
> + }
> +
> + if (!pipe->streaming_count)
> + media_graph_walk_cleanup(&pipe->graph);
> +
> + mutex_unlock(&mdev->graph_mutex);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_disable);
> +
> +__must_check int v4l2_pipeline_stream_enable(struct media_entity *entity,
> + struct media_pipeline *pipe)
> +{
> + struct media_device *mdev = entity->graph_obj.mdev;
> + int ret = 0;
> +
> + mutex_lock(&mdev->graph_mutex);
> +
> + if (!pipe->streaming_count) {
> + ret = media_graph_walk_init(&pipe->graph, mdev);
> + if (ret) {
> + mutex_unlock(&mdev->graph_mutex);
> + return ret;
> + }
> + }
> +
> + media_graph_walk_start(&pipe->graph, entity);
> +
> + while ((entity = media_graph_walk_next_stream(&pipe->graph))) {
> + struct v4l2_subdev *sd;
> +
> + if (!is_media_entity_v4l2_subdev(entity))
> + continue;
> +
> + sd = media_entity_to_v4l2_subdev(entity);
> + if (sd->stream_count++)
> + continue;
> +
> + ret = v4l2_subdev_call(sd, video, s_stream, true);
> + if (ret && ret != -ENOIOCTLCMD)
Same here
Thanks,
Helen
> + dev_dbg(mdev->dev,
> + "couldn't enable stream for subdevice '%s'\n",
> + entity->name);
> + v4l2_pipeline_stream_disable(entity, pipe);
> + break;
> + }
> +
> + dev_dbg(mdev->dev,
> + "stream enabled for subdevice '%s'\n", entity->name);
> + }
> +
> + if (!pipe->streaming_count)
> + media_graph_walk_cleanup(&pipe->graph);
> +
> + mutex_unlock(&mdev->graph_mutex);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_pipeline_stream_enable);
> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> index 150ee16ebd81..46c0857d07c4 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -519,6 +519,36 @@ int v4l2_fill_pixfmt(struct v4l2_pix_format *pixfmt, u32 pixelformat,
> int v4l2_fill_pixfmt_mp(struct v4l2_pix_format_mplane *pixfmt, u32 pixelformat,
> u32 width, u32 height);
>
> +/**
> + * media_pipeline_stop - Mark a pipeline as not streaming
> + * @entity: Starting entity
> + * @pipe: Media pipeline to iterate through the topology
> + *
> + * Call .s_stream(false) callback in all the subdevices participating in the
> + * stream, i.e. following links from sink to source.
> + *
> + * If multiple calls to v4l2_pipeline_stream_enable() have been made, the
> + * same number of calls to this function are required.
> + */
> +int v4l2_pipeline_stream_disable(struct media_entity *entity,
> + struct media_pipeline *pipe);
> +
> +/**
> + * v4l2_pipeline_stream_enable - Call .s_stream(true) callbacks in the stream
> + * @entity: Starting entity
> + * @pipe: Media pipeline to iterate through the topology
> + *
> + * Call .s_stream(true) callback in all the subdevices participating in the
> + * stream, i.e. following links from sink to source.
> + *
> + * Calls to this function can be nested, in which case the same number of
> + * v4l2_pipeline_stream_disable() calls will be required to stop streaming.
> + * The pipeline pointer must be identical for all nested calls to
> + * v4l2_pipeline_stream_enable().
> + */
> +__must_check int v4l2_pipeline_stream_enable(struct media_entity *entity,
> + struct media_pipeline *pipe);
> +
> static inline u64 v4l2_buffer_get_timestamp(const struct v4l2_buffer *buf)
> {
> /*
> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> index a4848de59852..20f913a9f70c 100644
> --- a/include/media/v4l2-subdev.h
> +++ b/include/media/v4l2-subdev.h
> @@ -838,6 +838,7 @@ struct v4l2_subdev_platform_data {
> * @subdev_notifier: A sub-device notifier implicitly registered for the sub-
> * device using v4l2_device_register_sensor_subdev().
> * @pdata: common part of subdevice platform data
> + * @stream_count: Stream count for the subdevice.
> *
> * Each instance of a subdev driver should create this struct, either
> * stand-alone or embedded in a larger struct.
> @@ -869,6 +870,7 @@ struct v4l2_subdev {
> struct v4l2_async_notifier *notifier;
> struct v4l2_async_notifier *subdev_notifier;
> struct v4l2_subdev_platform_data *pdata;
> + unsigned int stream_count;
> };
>
>
>