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Message-ID: <b7041eb2-adfc-abf4-336e-93a2b1154482@collabora.com>
Date: Mon, 16 Mar 2020 17:50:02 -0300
From: Helen Koike <helen.koike@...labora.com>
To: linux-media@...r.kernel.org
Cc: kernel@...labora.com, linux-kernel@...r.kernel.org,
linux-rockchip@...ts.infradead.org, hans.verkuil@...co.com,
niklas.soderlund@...natech.se, mchehab@...nel.org
Subject: Re: [PATCH 2/4] media: v4l2-common: add helper functions to call
s_stream() callbacks
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 <helen.koike@...labora.com>
> ---
>
> 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;
> };
>
>
>
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