diff mbox series

[v5,06/24] media: entity: Move the pipeline from entity to pads

Message ID 20210415130450.421168-7-tomi.valkeinen@ideasonboard.com (mailing list archive)
State New
Headers show
Series v4l: subdev internal routing | expand

Commit Message

Tomi Valkeinen April 15, 2021, 1:04 p.m. UTC
From: Sakari Ailus <sakari.ailus@linux.intel.com>

This moves the pipe and stream_count fields from struct media_entity to
struct media_pad. Effectively streams become pad-specific rather than
being entity specific, allowing several independent streams to traverse a
single entity and an entity to be part of several streams.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

- Update documentation to use 'pads'
- Use the media pad iterator in media_entity.c
- Update rcar-dma.c to use the new per-pad stream count
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

- Fix cleanup in the error path of __media_pipeline_start()
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
---
 drivers/media/mc/mc-entity.c                  | 68 +++++++++++--------
 drivers/media/platform/exynos4-is/fimc-isp.c  |  2 +-
 drivers/media/platform/exynos4-is/fimc-lite.c |  2 +-
 drivers/media/platform/omap3isp/isp.c         |  2 +-
 drivers/media/platform/omap3isp/ispvideo.c    |  2 +-
 drivers/media/platform/omap3isp/ispvideo.h    |  2 +-
 drivers/media/platform/rcar-vin/rcar-core.c   | 16 +++--
 drivers/media/platform/rcar-vin/rcar-dma.c    |  2 +-
 drivers/media/platform/xilinx/xilinx-dma.c    |  2 +-
 drivers/media/platform/xilinx/xilinx-dma.h    |  2 +-
 drivers/staging/media/imx/imx-media-utils.c   |  2 +-
 drivers/staging/media/omap4iss/iss.c          |  2 +-
 drivers/staging/media/omap4iss/iss_video.c    |  2 +-
 drivers/staging/media/omap4iss/iss_video.h    |  2 +-
 include/media/media-entity.h                  | 21 +++---
 15 files changed, 73 insertions(+), 56 deletions(-)

Comments

Laurent Pinchart April 18, 2021, 6 p.m. UTC | #1
Hi Tomi and Sakari,

Thank you for the patch.

On Thu, Apr 15, 2021 at 04:04:32PM +0300, Tomi Valkeinen wrote:
> From: Sakari Ailus <sakari.ailus@linux.intel.com>
> 
> This moves the pipe and stream_count fields from struct media_entity to
> struct media_pad. Effectively streams become pad-specific rather than
> being entity specific, allowing several independent streams to traverse a
> single entity and an entity to be part of several streams.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> - Update documentation to use 'pads'
> - Use the media pad iterator in media_entity.c
> - Update rcar-dma.c to use the new per-pad stream count
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> 
> - Fix cleanup in the error path of __media_pipeline_start()
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> ---
>  drivers/media/mc/mc-entity.c                  | 68 +++++++++++--------
>  drivers/media/platform/exynos4-is/fimc-isp.c  |  2 +-
>  drivers/media/platform/exynos4-is/fimc-lite.c |  2 +-
>  drivers/media/platform/omap3isp/isp.c         |  2 +-
>  drivers/media/platform/omap3isp/ispvideo.c    |  2 +-
>  drivers/media/platform/omap3isp/ispvideo.h    |  2 +-
>  drivers/media/platform/rcar-vin/rcar-core.c   | 16 +++--
>  drivers/media/platform/rcar-vin/rcar-dma.c    |  2 +-
>  drivers/media/platform/xilinx/xilinx-dma.c    |  2 +-
>  drivers/media/platform/xilinx/xilinx-dma.h    |  2 +-
>  drivers/staging/media/imx/imx-media-utils.c   |  2 +-
>  drivers/staging/media/omap4iss/iss.c          |  2 +-
>  drivers/staging/media/omap4iss/iss_video.c    |  2 +-
>  drivers/staging/media/omap4iss/iss_video.h    |  2 +-
>  include/media/media-entity.h                  | 21 +++---
>  15 files changed, 73 insertions(+), 56 deletions(-)
> 
> diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> index 830841e0cd28..b6e5aa639c26 100644
> --- a/drivers/media/mc/mc-entity.c
> +++ b/drivers/media/mc/mc-entity.c
> @@ -423,24 +423,28 @@ __must_check int __media_pipeline_start(struct media_entity *entity,
>  
>  	while ((pad = media_graph_walk_next(graph))) {
>  		struct media_entity *entity = pad->entity;
> +		bool skip_validation = pad->pipe;

I'd write

		bool skip_validation = pad->pipe != NULL;

> +		struct media_pad *iter;
>  
>  		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
>  		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
>  
> -		entity->stream_count++;
> -
> -		if (entity->pipe && entity->pipe != pipe) {
> -			pr_err("Pipe active for %s. Can't start for %s\n",
> -				entity->name,
> -				pad_err->entity->name);
> -			ret = -EBUSY;
> -			goto error;
> +		media_entity_for_each_pad(entity, iter) {
> +			if (iter->pipe && iter->pipe != pipe) {
> +				pr_err("Pipe active for %s. Can't start for %s\n",
> +				       entity->name, iter->entity->name);
> +				ret = -EBUSY;
> +			} else {
> +				iter->pipe = pipe;
> +			}
> +			iter->stream_count++;
>  		}
>  
> -		entity->pipe = pipe;
> +		if (ret)
> +			goto error;
>  
> -		/* Already streaming --- no need to check. */
> -		if (entity->stream_count > 1)
> +		/* Already part of the pipeline, skip validation. */
> +		if (skip_validation)
>  			continue;
>  
>  		if (!entity->ops || !entity->ops->link_validate)
> @@ -509,20 +513,23 @@ __must_check int __media_pipeline_start(struct media_entity *entity,
>  	media_graph_walk_start(graph, pad_err);
>  
>  	while ((pad_err = media_graph_walk_next(graph))) {
> -		struct media_entity *entity_err = pad_err->entity;
> -
> -		/* Sanity check for negative stream_count */
> -		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
> -			entity_err->stream_count--;
> -			if (entity_err->stream_count == 0)
> -				entity_err->pipe = NULL;
> +		struct media_entity *entity = pad_err->entity;
> +		struct media_pad *iter;
> +
> +		media_entity_for_each_pad(entity, iter) {
> +			/* Sanity check for negative stream_count */
> +			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
> +				--iter->stream_count;
> +				if (iter->stream_count == 0)
> +					iter->pipe = NULL;
> +			}
>  		}
>  
>  		/*
>  		 * We haven't increased stream_count further than this
>  		 * so we quit here.
>  		 */
> -		if (pad_err == pad)
> +		if (pad_err->entity == pad->entity)
>  			break;
>  	}
>  
> @@ -549,7 +556,7 @@ EXPORT_SYMBOL_GPL(media_pipeline_start);
>  
>  void __media_pipeline_stop(struct media_entity *entity)
>  {
> -	struct media_pipeline *pipe = entity->pipe;
> +	struct media_pipeline *pipe = entity->pads->pipe;
>  	struct media_graph *graph = &pipe->graph;
>  	struct media_pad *pad;
>  
> @@ -564,12 +571,15 @@ void __media_pipeline_stop(struct media_entity *entity)
>  
>  	while ((pad = media_graph_walk_next(graph))) {
>  		struct media_entity *entity = pad->entity;
> -
> -		/* Sanity check for negative stream_count */
> -		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
> -			entity->stream_count--;
> -			if (entity->stream_count == 0)
> -				entity->pipe = NULL;
> +		struct media_pad *iter;
> +
> +		media_entity_for_each_pad(entity, iter) {
> +			/* Sanity check for negative stream_count */
> +			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
> +				iter->stream_count--;
> +				if (iter->stream_count == 0)
> +					iter->pipe = NULL;
> +			}
>  		}
>  	}
>  
> @@ -839,7 +849,7 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
>  {
>  	const u32 mask = MEDIA_LNK_FL_ENABLED;
>  	struct media_device *mdev;
> -	struct media_entity *source, *sink;
> +	struct media_pad *source, *sink;
>  	int ret = -EBUSY;
>  
>  	if (link == NULL)
> @@ -855,8 +865,8 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
>  	if (link->flags == flags)
>  		return 0;
>  
> -	source = link->source->entity;
> -	sink = link->sink->entity;
> +	source = link->source;
> +	sink = link->sink;
>  
>  	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
>  	    (source->stream_count || sink->stream_count))
> diff --git a/drivers/media/platform/exynos4-is/fimc-isp.c b/drivers/media/platform/exynos4-is/fimc-isp.c
> index a77c49b18511..563d07f630bc 100644
> --- a/drivers/media/platform/exynos4-is/fimc-isp.c
> +++ b/drivers/media/platform/exynos4-is/fimc-isp.c
> @@ -223,7 +223,7 @@ static int fimc_isp_subdev_set_fmt(struct v4l2_subdev *sd,
>  			}
>  		}
>  	} else {
> -		if (sd->entity.stream_count == 0) {
> +		if (sd->entity.pads->stream_count == 0) {
>  			if (fmt->pad == FIMC_ISP_SD_PAD_SINK) {
>  				struct v4l2_subdev_format format = *fmt;
>  
> diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c
> index fe20af3a7178..56773a0be8d9 100644
> --- a/drivers/media/platform/exynos4-is/fimc-lite.c
> +++ b/drivers/media/platform/exynos4-is/fimc-lite.c
> @@ -1070,7 +1070,7 @@ static int fimc_lite_subdev_set_fmt(struct v4l2_subdev *sd,
>  	mutex_lock(&fimc->lock);
>  
>  	if ((atomic_read(&fimc->out_path) == FIMC_IO_ISP &&
> -	    sd->entity.stream_count > 0) ||
> +	    sd->entity.pads->stream_count > 0) ||
>  	    (atomic_read(&fimc->out_path) == FIMC_IO_DMA &&
>  	    vb2_is_busy(&fimc->vb_queue))) {
>  		mutex_unlock(&fimc->lock);
> diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
> index a6bb7d9bf75f..4ef623f10a44 100644
> --- a/drivers/media/platform/omap3isp/isp.c
> +++ b/drivers/media/platform/omap3isp/isp.c
> @@ -930,7 +930,7 @@ static int isp_pipeline_is_last(struct media_entity *me)
>  	struct isp_pipeline *pipe;
>  	struct media_pad *pad;
>  
> -	if (!me->pipe)
> +	if (!me->pads->pipe)
>  		return 0;
>  	pipe = to_isp_pipeline(me);
>  	if (pipe->stream_state == ISP_PIPELINE_STREAM_STOPPED)
> diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
> index 49cde04bfb21..f3bee79cdd85 100644
> --- a/drivers/media/platform/omap3isp/ispvideo.c
> +++ b/drivers/media/platform/omap3isp/ispvideo.c
> @@ -1094,7 +1094,7 @@ isp_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
>  	/* Start streaming on the pipeline. No link touching an entity in the
>  	 * pipeline can be activated or deactivated once streaming is started.
>  	 */
> -	pipe = video->video.entity.pipe
> +	pipe = video->video.entity.pads->pipe
>  	     ? to_isp_pipeline(&video->video.entity) : &video->pipe;
>  
>  	ret = media_entity_enum_init(&pipe->ent_enum, &video->isp->media_dev);
> diff --git a/drivers/media/platform/omap3isp/ispvideo.h b/drivers/media/platform/omap3isp/ispvideo.h
> index a0908670c0cf..4c9c5b719ec5 100644
> --- a/drivers/media/platform/omap3isp/ispvideo.h
> +++ b/drivers/media/platform/omap3isp/ispvideo.h
> @@ -100,7 +100,7 @@ struct isp_pipeline {
>  };
>  
>  #define to_isp_pipeline(__e) \
> -	container_of((__e)->pipe, struct isp_pipeline, pipe)
> +	container_of((__e)->pads->pipe, struct isp_pipeline, pipe)
>  
>  static inline int isp_pipeline_ready(struct isp_pipeline *pipe)
>  {
> diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> index cb3025992817..07ec008aacc4 100644
> --- a/drivers/media/platform/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> @@ -132,13 +132,17 @@ static int rvin_group_link_notify(struct media_link *link, u32 flags,
>  		return 0;
>  
>  	/*
> -	 * Don't allow link changes if any entity in the graph is
> -	 * streaming, modifying the CHSEL register fields can disrupt
> -	 * running streams.
> +	 * Don't allow link changes if any stream in the graph is active as
> +	 * modifying the CHSEL register fields can disrupt running streams.
>  	 */
> -	media_device_for_each_entity(entity, &group->mdev)
> -		if (entity->stream_count)
> -			return -EBUSY;
> +	media_device_for_each_entity(entity, &group->mdev) {
> +		struct media_pad *iter;
> +
> +		media_entity_for_each_pad(entity, iter) {
> +			if (iter->stream_count)
> +				return -EBUSY;
> +		}

Would it be enough to test entity->pads->stream_count, as the stream
count should be the same for all pads ?

> +	}
>  
>  	mutex_lock(&group->lock);
>  
> diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> index f30dafbdf61c..7994262c9b63 100644
> --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> @@ -1231,7 +1231,7 @@ static int rvin_set_stream(struct rvin_dev *vin, int on)
>  	 */
>  	mdev = vin->vdev.entity.graph_obj.mdev;
>  	mutex_lock(&mdev->graph_mutex);
> -	pipe = sd->entity.pipe ? sd->entity.pipe : &vin->vdev.pipe;
> +	pipe = sd->entity.pads->pipe ? sd->entity.pads->pipe : &vin->vdev.pipe;
>  	ret = __media_pipeline_start(&vin->vdev.entity, pipe);
>  	mutex_unlock(&mdev->graph_mutex);
>  	if (ret)
> diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> index 8df3c43aecbe..7fa0467dddde 100644
> --- a/drivers/media/platform/xilinx/xilinx-dma.c
> +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> @@ -403,7 +403,7 @@ static int xvip_dma_start_streaming(struct vb2_queue *vq, unsigned int count)
>  	 * Use the pipeline object embedded in the first DMA object that starts
>  	 * streaming.
>  	 */
> -	pipe = dma->video.entity.pipe
> +	pipe = dma->video.entity.pads->pipe
>  	     ? to_xvip_pipeline(&dma->video.entity) : &dma->pipe;
>  
>  	ret = media_pipeline_start(&dma->video.entity, &pipe->pipe);
> diff --git a/drivers/media/platform/xilinx/xilinx-dma.h b/drivers/media/platform/xilinx/xilinx-dma.h
> index 2378bdae57ae..69ced71a5696 100644
> --- a/drivers/media/platform/xilinx/xilinx-dma.h
> +++ b/drivers/media/platform/xilinx/xilinx-dma.h
> @@ -47,7 +47,7 @@ struct xvip_pipeline {
>  
>  static inline struct xvip_pipeline *to_xvip_pipeline(struct media_entity *e)
>  {
> -	return container_of(e->pipe, struct xvip_pipeline, pipe);
> +	return container_of(e->pads->pipe, struct xvip_pipeline, pipe);
>  }
>  
>  /**
> diff --git a/drivers/staging/media/imx/imx-media-utils.c b/drivers/staging/media/imx/imx-media-utils.c
> index 5128915a5d6f..04b7c6bdcd85 100644
> --- a/drivers/staging/media/imx/imx-media-utils.c
> +++ b/drivers/staging/media/imx/imx-media-utils.c
> @@ -913,7 +913,7 @@ int imx_media_pipeline_set_stream(struct imx_media_dev *imxmd,
>  			__media_pipeline_stop(entity);
>  	} else {
>  		v4l2_subdev_call(sd, video, s_stream, 0);
> -		if (entity->pipe)
> +		if (entity->pads->pipe)
>  			__media_pipeline_stop(entity);
>  	}
>  
> diff --git a/drivers/staging/media/omap4iss/iss.c b/drivers/staging/media/omap4iss/iss.c
> index 085397045b36..4f4573219337 100644
> --- a/drivers/staging/media/omap4iss/iss.c
> +++ b/drivers/staging/media/omap4iss/iss.c
> @@ -543,7 +543,7 @@ static int iss_pipeline_is_last(struct media_entity *me)
>  	struct iss_pipeline *pipe;
>  	struct media_pad *pad;
>  
> -	if (!me->pipe)
> +	if (!me->pads->pipe)
>  		return 0;
>  	pipe = to_iss_pipeline(me);
>  	if (pipe->stream_state == ISS_PIPELINE_STREAM_STOPPED)
> diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
> index 9f3ff5a37d90..9d7bf8c85558 100644
> --- a/drivers/staging/media/omap4iss/iss_video.c
> +++ b/drivers/staging/media/omap4iss/iss_video.c
> @@ -870,7 +870,7 @@ iss_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
>  	 * Start streaming on the pipeline. No link touching an entity in the
>  	 * pipeline can be activated or deactivated once streaming is started.
>  	 */
> -	pipe = pad->entity->pipe
> +	pipe = pad->pipe
>  	     ? to_iss_pipeline(pad->entity) : &video->pipe;
>  	pipe->external = NULL;
>  	pipe->external_rate = 0;
> diff --git a/drivers/staging/media/omap4iss/iss_video.h b/drivers/staging/media/omap4iss/iss_video.h
> index 526281bf0051..9b8ec27bf87d 100644
> --- a/drivers/staging/media/omap4iss/iss_video.h
> +++ b/drivers/staging/media/omap4iss/iss_video.h
> @@ -91,7 +91,7 @@ struct iss_pipeline {
>  };
>  
>  #define to_iss_pipeline(__e) \
> -	container_of((__e)->pipe, struct iss_pipeline, pipe)
> +	container_of((__e)->pads->pipe, struct iss_pipeline, pipe)
>  
>  static inline int iss_pipeline_ready(struct iss_pipeline *pipe)
>  {
> diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> index 52b1a1cab57a..b8f94662526c 100644
> --- a/include/media/media-entity.h
> +++ b/include/media/media-entity.h
> @@ -180,15 +180,24 @@ enum media_pad_signal_type {
>   *
>   * @graph_obj:	Embedded structure containing the media object common data
>   * @entity:	Entity this pad belongs to
> + * @pipe:	Pipeline this pad belongs to.
> + * @stream_count: Stream count for the pad.

No period at the end of the lines.

>   * @index:	Pad index in the entity pads array, numbered from 0 to n
>   * @sig_type:	Type of the signal inside a media pad
>   * @flags:	Pad flags, as defined in
>   *		:ref:`include/uapi/linux/media.h <media_header>`
>   *		(seek for ``MEDIA_PAD_FL_*``)
> + * .. note::
> + *
> + *    @stream_count reference count must never be negative, but is a signed
> + *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
> + *    detect reference count bugs that would make them negative.

s/them/it/

>   */
>  struct media_pad {
>  	struct media_gobj graph_obj;	/* must be first field in struct */
>  	struct media_entity *entity;
> +	struct media_pipeline *pipe;
> +	int stream_count;
>  	u16 index;
>  	enum media_pad_signal_type sig_type;
>  	unsigned long flags;
> @@ -267,9 +276,7 @@ enum media_entity_type {
>   * @pads:	Pads array with the size defined by @num_pads.
>   * @links:	List of data links.
>   * @ops:	Entity operations.
> - * @stream_count: Stream count for the entity.
>   * @use_count:	Use count for the entity.
> - * @pipe:	Pipeline this entity belongs to.
>   * @info:	Union with devnode information.  Kept just for backward
>   *		compatibility.
>   * @info.dev:	Contains device major and minor info.
> @@ -282,10 +289,9 @@ enum media_entity_type {
>   *
>   * .. note::
>   *
> - *    @stream_count and @use_count reference counts must never be
> - *    negative, but are signed integers on purpose: a simple ``WARN_ON(<0)``
> - *    check can be used to detect reference count bugs that would make them
> - *    negative.
> + *    @use_count reference count must never be negative, but is a signed
> + *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
> + *    detect reference count bugs that would make them negative.

s/them/it/

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

>   */
>  struct media_entity {
>  	struct media_gobj graph_obj;	/* must be first field in struct */
> @@ -304,11 +310,8 @@ struct media_entity {
>  
>  	const struct media_entity_operations *ops;
>  
> -	int stream_count;
>  	int use_count;
>  
> -	struct media_pipeline *pipe;
> -
>  	union {
>  		struct {
>  			u32 major;
Sakari Ailus April 20, 2021, 11:38 a.m. UTC | #2
Hi Laurent,

On Sun, Apr 18, 2021 at 09:00:21PM +0300, Laurent Pinchart wrote:
> Hi Tomi and Sakari,
> 
> Thank you for the patch.
> 
> On Thu, Apr 15, 2021 at 04:04:32PM +0300, Tomi Valkeinen wrote:
> > From: Sakari Ailus <sakari.ailus@linux.intel.com>
> > 
> > This moves the pipe and stream_count fields from struct media_entity to
> > struct media_pad. Effectively streams become pad-specific rather than
> > being entity specific, allowing several independent streams to traverse a
> > single entity and an entity to be part of several streams.
> > 
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > - Update documentation to use 'pads'
> > - Use the media pad iterator in media_entity.c
> > - Update rcar-dma.c to use the new per-pad stream count
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > 
> > - Fix cleanup in the error path of __media_pipeline_start()
> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
> > ---
> >  drivers/media/mc/mc-entity.c                  | 68 +++++++++++--------
> >  drivers/media/platform/exynos4-is/fimc-isp.c  |  2 +-
> >  drivers/media/platform/exynos4-is/fimc-lite.c |  2 +-
> >  drivers/media/platform/omap3isp/isp.c         |  2 +-
> >  drivers/media/platform/omap3isp/ispvideo.c    |  2 +-
> >  drivers/media/platform/omap3isp/ispvideo.h    |  2 +-
> >  drivers/media/platform/rcar-vin/rcar-core.c   | 16 +++--
> >  drivers/media/platform/rcar-vin/rcar-dma.c    |  2 +-
> >  drivers/media/platform/xilinx/xilinx-dma.c    |  2 +-
> >  drivers/media/platform/xilinx/xilinx-dma.h    |  2 +-
> >  drivers/staging/media/imx/imx-media-utils.c   |  2 +-
> >  drivers/staging/media/omap4iss/iss.c          |  2 +-
> >  drivers/staging/media/omap4iss/iss_video.c    |  2 +-
> >  drivers/staging/media/omap4iss/iss_video.h    |  2 +-
> >  include/media/media-entity.h                  | 21 +++---
> >  15 files changed, 73 insertions(+), 56 deletions(-)
> > 
> > diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
> > index 830841e0cd28..b6e5aa639c26 100644
> > --- a/drivers/media/mc/mc-entity.c
> > +++ b/drivers/media/mc/mc-entity.c
> > @@ -423,24 +423,28 @@ __must_check int __media_pipeline_start(struct media_entity *entity,
> >  
> >  	while ((pad = media_graph_walk_next(graph))) {
> >  		struct media_entity *entity = pad->entity;
> > +		bool skip_validation = pad->pipe;
> 
> I'd write
> 
> 		bool skip_validation = pad->pipe != NULL;
> 
> > +		struct media_pad *iter;
> >  
> >  		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
> >  		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
> >  
> > -		entity->stream_count++;
> > -
> > -		if (entity->pipe && entity->pipe != pipe) {
> > -			pr_err("Pipe active for %s. Can't start for %s\n",
> > -				entity->name,
> > -				pad_err->entity->name);
> > -			ret = -EBUSY;
> > -			goto error;
> > +		media_entity_for_each_pad(entity, iter) {
> > +			if (iter->pipe && iter->pipe != pipe) {
> > +				pr_err("Pipe active for %s. Can't start for %s\n",
> > +				       entity->name, iter->entity->name);
> > +				ret = -EBUSY;
> > +			} else {
> > +				iter->pipe = pipe;
> > +			}
> > +			iter->stream_count++;
> >  		}
> >  
> > -		entity->pipe = pipe;
> > +		if (ret)
> > +			goto error;
> >  
> > -		/* Already streaming --- no need to check. */
> > -		if (entity->stream_count > 1)
> > +		/* Already part of the pipeline, skip validation. */
> > +		if (skip_validation)
> >  			continue;
> >  
> >  		if (!entity->ops || !entity->ops->link_validate)
> > @@ -509,20 +513,23 @@ __must_check int __media_pipeline_start(struct media_entity *entity,
> >  	media_graph_walk_start(graph, pad_err);
> >  
> >  	while ((pad_err = media_graph_walk_next(graph))) {
> > -		struct media_entity *entity_err = pad_err->entity;
> > -
> > -		/* Sanity check for negative stream_count */
> > -		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
> > -			entity_err->stream_count--;
> > -			if (entity_err->stream_count == 0)
> > -				entity_err->pipe = NULL;
> > +		struct media_entity *entity = pad_err->entity;
> > +		struct media_pad *iter;
> > +
> > +		media_entity_for_each_pad(entity, iter) {
> > +			/* Sanity check for negative stream_count */
> > +			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
> > +				--iter->stream_count;
> > +				if (iter->stream_count == 0)
> > +					iter->pipe = NULL;
> > +			}
> >  		}
> >  
> >  		/*
> >  		 * We haven't increased stream_count further than this
> >  		 * so we quit here.
> >  		 */
> > -		if (pad_err == pad)
> > +		if (pad_err->entity == pad->entity)
> >  			break;
> >  	}
> >  
> > @@ -549,7 +556,7 @@ EXPORT_SYMBOL_GPL(media_pipeline_start);
> >  
> >  void __media_pipeline_stop(struct media_entity *entity)
> >  {
> > -	struct media_pipeline *pipe = entity->pipe;
> > +	struct media_pipeline *pipe = entity->pads->pipe;
> >  	struct media_graph *graph = &pipe->graph;
> >  	struct media_pad *pad;
> >  
> > @@ -564,12 +571,15 @@ void __media_pipeline_stop(struct media_entity *entity)
> >  
> >  	while ((pad = media_graph_walk_next(graph))) {
> >  		struct media_entity *entity = pad->entity;
> > -
> > -		/* Sanity check for negative stream_count */
> > -		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
> > -			entity->stream_count--;
> > -			if (entity->stream_count == 0)
> > -				entity->pipe = NULL;
> > +		struct media_pad *iter;
> > +
> > +		media_entity_for_each_pad(entity, iter) {
> > +			/* Sanity check for negative stream_count */
> > +			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
> > +				iter->stream_count--;
> > +				if (iter->stream_count == 0)
> > +					iter->pipe = NULL;
> > +			}
> >  		}
> >  	}
> >  
> > @@ -839,7 +849,7 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
> >  {
> >  	const u32 mask = MEDIA_LNK_FL_ENABLED;
> >  	struct media_device *mdev;
> > -	struct media_entity *source, *sink;
> > +	struct media_pad *source, *sink;
> >  	int ret = -EBUSY;
> >  
> >  	if (link == NULL)
> > @@ -855,8 +865,8 @@ int __media_entity_setup_link(struct media_link *link, u32 flags)
> >  	if (link->flags == flags)
> >  		return 0;
> >  
> > -	source = link->source->entity;
> > -	sink = link->sink->entity;
> > +	source = link->source;
> > +	sink = link->sink;
> >  
> >  	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
> >  	    (source->stream_count || sink->stream_count))
> > diff --git a/drivers/media/platform/exynos4-is/fimc-isp.c b/drivers/media/platform/exynos4-is/fimc-isp.c
> > index a77c49b18511..563d07f630bc 100644
> > --- a/drivers/media/platform/exynos4-is/fimc-isp.c
> > +++ b/drivers/media/platform/exynos4-is/fimc-isp.c
> > @@ -223,7 +223,7 @@ static int fimc_isp_subdev_set_fmt(struct v4l2_subdev *sd,
> >  			}
> >  		}
> >  	} else {
> > -		if (sd->entity.stream_count == 0) {
> > +		if (sd->entity.pads->stream_count == 0) {
> >  			if (fmt->pad == FIMC_ISP_SD_PAD_SINK) {
> >  				struct v4l2_subdev_format format = *fmt;
> >  
> > diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c
> > index fe20af3a7178..56773a0be8d9 100644
> > --- a/drivers/media/platform/exynos4-is/fimc-lite.c
> > +++ b/drivers/media/platform/exynos4-is/fimc-lite.c
> > @@ -1070,7 +1070,7 @@ static int fimc_lite_subdev_set_fmt(struct v4l2_subdev *sd,
> >  	mutex_lock(&fimc->lock);
> >  
> >  	if ((atomic_read(&fimc->out_path) == FIMC_IO_ISP &&
> > -	    sd->entity.stream_count > 0) ||
> > +	    sd->entity.pads->stream_count > 0) ||
> >  	    (atomic_read(&fimc->out_path) == FIMC_IO_DMA &&
> >  	    vb2_is_busy(&fimc->vb_queue))) {
> >  		mutex_unlock(&fimc->lock);
> > diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
> > index a6bb7d9bf75f..4ef623f10a44 100644
> > --- a/drivers/media/platform/omap3isp/isp.c
> > +++ b/drivers/media/platform/omap3isp/isp.c
> > @@ -930,7 +930,7 @@ static int isp_pipeline_is_last(struct media_entity *me)
> >  	struct isp_pipeline *pipe;
> >  	struct media_pad *pad;
> >  
> > -	if (!me->pipe)
> > +	if (!me->pads->pipe)
> >  		return 0;
> >  	pipe = to_isp_pipeline(me);
> >  	if (pipe->stream_state == ISP_PIPELINE_STREAM_STOPPED)
> > diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
> > index 49cde04bfb21..f3bee79cdd85 100644
> > --- a/drivers/media/platform/omap3isp/ispvideo.c
> > +++ b/drivers/media/platform/omap3isp/ispvideo.c
> > @@ -1094,7 +1094,7 @@ isp_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
> >  	/* Start streaming on the pipeline. No link touching an entity in the
> >  	 * pipeline can be activated or deactivated once streaming is started.
> >  	 */
> > -	pipe = video->video.entity.pipe
> > +	pipe = video->video.entity.pads->pipe
> >  	     ? to_isp_pipeline(&video->video.entity) : &video->pipe;
> >  
> >  	ret = media_entity_enum_init(&pipe->ent_enum, &video->isp->media_dev);
> > diff --git a/drivers/media/platform/omap3isp/ispvideo.h b/drivers/media/platform/omap3isp/ispvideo.h
> > index a0908670c0cf..4c9c5b719ec5 100644
> > --- a/drivers/media/platform/omap3isp/ispvideo.h
> > +++ b/drivers/media/platform/omap3isp/ispvideo.h
> > @@ -100,7 +100,7 @@ struct isp_pipeline {
> >  };
> >  
> >  #define to_isp_pipeline(__e) \
> > -	container_of((__e)->pipe, struct isp_pipeline, pipe)
> > +	container_of((__e)->pads->pipe, struct isp_pipeline, pipe)
> >  
> >  static inline int isp_pipeline_ready(struct isp_pipeline *pipe)
> >  {
> > diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> > index cb3025992817..07ec008aacc4 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-core.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> > @@ -132,13 +132,17 @@ static int rvin_group_link_notify(struct media_link *link, u32 flags,
> >  		return 0;
> >  
> >  	/*
> > -	 * Don't allow link changes if any entity in the graph is
> > -	 * streaming, modifying the CHSEL register fields can disrupt
> > -	 * running streams.
> > +	 * Don't allow link changes if any stream in the graph is active as
> > +	 * modifying the CHSEL register fields can disrupt running streams.
> >  	 */
> > -	media_device_for_each_entity(entity, &group->mdev)
> > -		if (entity->stream_count)
> > -			return -EBUSY;
> > +	media_device_for_each_entity(entity, &group->mdev) {
> > +		struct media_pad *iter;
> > +
> > +		media_entity_for_each_pad(entity, iter) {
> > +			if (iter->stream_count)
> > +				return -EBUSY;
> > +		}
> 
> Would it be enough to test entity->pads->stream_count, as the stream
> count should be the same for all pads ?

For now, yes. But once routes are added, it wouldn't be enough anymore,
would it?

> 
> > +	}
> >  
> >  	mutex_lock(&group->lock);
> >  
> > diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> > index f30dafbdf61c..7994262c9b63 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> > @@ -1231,7 +1231,7 @@ static int rvin_set_stream(struct rvin_dev *vin, int on)
> >  	 */
> >  	mdev = vin->vdev.entity.graph_obj.mdev;
> >  	mutex_lock(&mdev->graph_mutex);
> > -	pipe = sd->entity.pipe ? sd->entity.pipe : &vin->vdev.pipe;
> > +	pipe = sd->entity.pads->pipe ? sd->entity.pads->pipe : &vin->vdev.pipe;
> >  	ret = __media_pipeline_start(&vin->vdev.entity, pipe);
> >  	mutex_unlock(&mdev->graph_mutex);
> >  	if (ret)
> > diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
> > index 8df3c43aecbe..7fa0467dddde 100644
> > --- a/drivers/media/platform/xilinx/xilinx-dma.c
> > +++ b/drivers/media/platform/xilinx/xilinx-dma.c
> > @@ -403,7 +403,7 @@ static int xvip_dma_start_streaming(struct vb2_queue *vq, unsigned int count)
> >  	 * Use the pipeline object embedded in the first DMA object that starts
> >  	 * streaming.
> >  	 */
> > -	pipe = dma->video.entity.pipe
> > +	pipe = dma->video.entity.pads->pipe
> >  	     ? to_xvip_pipeline(&dma->video.entity) : &dma->pipe;
> >  
> >  	ret = media_pipeline_start(&dma->video.entity, &pipe->pipe);
> > diff --git a/drivers/media/platform/xilinx/xilinx-dma.h b/drivers/media/platform/xilinx/xilinx-dma.h
> > index 2378bdae57ae..69ced71a5696 100644
> > --- a/drivers/media/platform/xilinx/xilinx-dma.h
> > +++ b/drivers/media/platform/xilinx/xilinx-dma.h
> > @@ -47,7 +47,7 @@ struct xvip_pipeline {
> >  
> >  static inline struct xvip_pipeline *to_xvip_pipeline(struct media_entity *e)
> >  {
> > -	return container_of(e->pipe, struct xvip_pipeline, pipe);
> > +	return container_of(e->pads->pipe, struct xvip_pipeline, pipe);
> >  }
> >  
> >  /**
> > diff --git a/drivers/staging/media/imx/imx-media-utils.c b/drivers/staging/media/imx/imx-media-utils.c
> > index 5128915a5d6f..04b7c6bdcd85 100644
> > --- a/drivers/staging/media/imx/imx-media-utils.c
> > +++ b/drivers/staging/media/imx/imx-media-utils.c
> > @@ -913,7 +913,7 @@ int imx_media_pipeline_set_stream(struct imx_media_dev *imxmd,
> >  			__media_pipeline_stop(entity);
> >  	} else {
> >  		v4l2_subdev_call(sd, video, s_stream, 0);
> > -		if (entity->pipe)
> > +		if (entity->pads->pipe)
> >  			__media_pipeline_stop(entity);
> >  	}
> >  
> > diff --git a/drivers/staging/media/omap4iss/iss.c b/drivers/staging/media/omap4iss/iss.c
> > index 085397045b36..4f4573219337 100644
> > --- a/drivers/staging/media/omap4iss/iss.c
> > +++ b/drivers/staging/media/omap4iss/iss.c
> > @@ -543,7 +543,7 @@ static int iss_pipeline_is_last(struct media_entity *me)
> >  	struct iss_pipeline *pipe;
> >  	struct media_pad *pad;
> >  
> > -	if (!me->pipe)
> > +	if (!me->pads->pipe)
> >  		return 0;
> >  	pipe = to_iss_pipeline(me);
> >  	if (pipe->stream_state == ISS_PIPELINE_STREAM_STOPPED)
> > diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
> > index 9f3ff5a37d90..9d7bf8c85558 100644
> > --- a/drivers/staging/media/omap4iss/iss_video.c
> > +++ b/drivers/staging/media/omap4iss/iss_video.c
> > @@ -870,7 +870,7 @@ iss_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
> >  	 * Start streaming on the pipeline. No link touching an entity in the
> >  	 * pipeline can be activated or deactivated once streaming is started.
> >  	 */
> > -	pipe = pad->entity->pipe
> > +	pipe = pad->pipe
> >  	     ? to_iss_pipeline(pad->entity) : &video->pipe;
> >  	pipe->external = NULL;
> >  	pipe->external_rate = 0;
> > diff --git a/drivers/staging/media/omap4iss/iss_video.h b/drivers/staging/media/omap4iss/iss_video.h
> > index 526281bf0051..9b8ec27bf87d 100644
> > --- a/drivers/staging/media/omap4iss/iss_video.h
> > +++ b/drivers/staging/media/omap4iss/iss_video.h
> > @@ -91,7 +91,7 @@ struct iss_pipeline {
> >  };
> >  
> >  #define to_iss_pipeline(__e) \
> > -	container_of((__e)->pipe, struct iss_pipeline, pipe)
> > +	container_of((__e)->pads->pipe, struct iss_pipeline, pipe)
> >  
> >  static inline int iss_pipeline_ready(struct iss_pipeline *pipe)
> >  {
> > diff --git a/include/media/media-entity.h b/include/media/media-entity.h
> > index 52b1a1cab57a..b8f94662526c 100644
> > --- a/include/media/media-entity.h
> > +++ b/include/media/media-entity.h
> > @@ -180,15 +180,24 @@ enum media_pad_signal_type {
> >   *
> >   * @graph_obj:	Embedded structure containing the media object common data
> >   * @entity:	Entity this pad belongs to
> > + * @pipe:	Pipeline this pad belongs to.
> > + * @stream_count: Stream count for the pad.
> 
> No period at the end of the lines.
> 
> >   * @index:	Pad index in the entity pads array, numbered from 0 to n
> >   * @sig_type:	Type of the signal inside a media pad
> >   * @flags:	Pad flags, as defined in
> >   *		:ref:`include/uapi/linux/media.h <media_header>`
> >   *		(seek for ``MEDIA_PAD_FL_*``)
> > + * .. note::
> > + *
> > + *    @stream_count reference count must never be negative, but is a signed
> > + *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
> > + *    detect reference count bugs that would make them negative.
> 
> s/them/it/
> 
> >   */
> >  struct media_pad {
> >  	struct media_gobj graph_obj;	/* must be first field in struct */
> >  	struct media_entity *entity;
> > +	struct media_pipeline *pipe;
> > +	int stream_count;
> >  	u16 index;
> >  	enum media_pad_signal_type sig_type;
> >  	unsigned long flags;
> > @@ -267,9 +276,7 @@ enum media_entity_type {
> >   * @pads:	Pads array with the size defined by @num_pads.
> >   * @links:	List of data links.
> >   * @ops:	Entity operations.
> > - * @stream_count: Stream count for the entity.
> >   * @use_count:	Use count for the entity.
> > - * @pipe:	Pipeline this entity belongs to.
> >   * @info:	Union with devnode information.  Kept just for backward
> >   *		compatibility.
> >   * @info.dev:	Contains device major and minor info.
> > @@ -282,10 +289,9 @@ enum media_entity_type {
> >   *
> >   * .. note::
> >   *
> > - *    @stream_count and @use_count reference counts must never be
> > - *    negative, but are signed integers on purpose: a simple ``WARN_ON(<0)``
> > - *    check can be used to detect reference count bugs that would make them
> > - *    negative.
> > + *    @use_count reference count must never be negative, but is a signed
> > + *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
> > + *    detect reference count bugs that would make them negative.
> 
> s/them/it/
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> >   */
> >  struct media_entity {
> >  	struct media_gobj graph_obj;	/* must be first field in struct */
> > @@ -304,11 +310,8 @@ struct media_entity {
> >  
> >  	const struct media_entity_operations *ops;
> >  
> > -	int stream_count;
> >  	int use_count;
> >  
> > -	struct media_pipeline *pipe;
> > -
> >  	union {
> >  		struct {
> >  			u32 major;
>
diff mbox series

Patch

diff --git a/drivers/media/mc/mc-entity.c b/drivers/media/mc/mc-entity.c
index 830841e0cd28..b6e5aa639c26 100644
--- a/drivers/media/mc/mc-entity.c
+++ b/drivers/media/mc/mc-entity.c
@@ -423,24 +423,28 @@  __must_check int __media_pipeline_start(struct media_entity *entity,
 
 	while ((pad = media_graph_walk_next(graph))) {
 		struct media_entity *entity = pad->entity;
+		bool skip_validation = pad->pipe;
+		struct media_pad *iter;
 
 		DECLARE_BITMAP(active, MEDIA_ENTITY_MAX_PADS);
 		DECLARE_BITMAP(has_no_links, MEDIA_ENTITY_MAX_PADS);
 
-		entity->stream_count++;
-
-		if (entity->pipe && entity->pipe != pipe) {
-			pr_err("Pipe active for %s. Can't start for %s\n",
-				entity->name,
-				pad_err->entity->name);
-			ret = -EBUSY;
-			goto error;
+		media_entity_for_each_pad(entity, iter) {
+			if (iter->pipe && iter->pipe != pipe) {
+				pr_err("Pipe active for %s. Can't start for %s\n",
+				       entity->name, iter->entity->name);
+				ret = -EBUSY;
+			} else {
+				iter->pipe = pipe;
+			}
+			iter->stream_count++;
 		}
 
-		entity->pipe = pipe;
+		if (ret)
+			goto error;
 
-		/* Already streaming --- no need to check. */
-		if (entity->stream_count > 1)
+		/* Already part of the pipeline, skip validation. */
+		if (skip_validation)
 			continue;
 
 		if (!entity->ops || !entity->ops->link_validate)
@@ -509,20 +513,23 @@  __must_check int __media_pipeline_start(struct media_entity *entity,
 	media_graph_walk_start(graph, pad_err);
 
 	while ((pad_err = media_graph_walk_next(graph))) {
-		struct media_entity *entity_err = pad_err->entity;
-
-		/* Sanity check for negative stream_count */
-		if (!WARN_ON_ONCE(entity_err->stream_count <= 0)) {
-			entity_err->stream_count--;
-			if (entity_err->stream_count == 0)
-				entity_err->pipe = NULL;
+		struct media_entity *entity = pad_err->entity;
+		struct media_pad *iter;
+
+		media_entity_for_each_pad(entity, iter) {
+			/* Sanity check for negative stream_count */
+			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
+				--iter->stream_count;
+				if (iter->stream_count == 0)
+					iter->pipe = NULL;
+			}
 		}
 
 		/*
 		 * We haven't increased stream_count further than this
 		 * so we quit here.
 		 */
-		if (pad_err == pad)
+		if (pad_err->entity == pad->entity)
 			break;
 	}
 
@@ -549,7 +556,7 @@  EXPORT_SYMBOL_GPL(media_pipeline_start);
 
 void __media_pipeline_stop(struct media_entity *entity)
 {
-	struct media_pipeline *pipe = entity->pipe;
+	struct media_pipeline *pipe = entity->pads->pipe;
 	struct media_graph *graph = &pipe->graph;
 	struct media_pad *pad;
 
@@ -564,12 +571,15 @@  void __media_pipeline_stop(struct media_entity *entity)
 
 	while ((pad = media_graph_walk_next(graph))) {
 		struct media_entity *entity = pad->entity;
-
-		/* Sanity check for negative stream_count */
-		if (!WARN_ON_ONCE(entity->stream_count <= 0)) {
-			entity->stream_count--;
-			if (entity->stream_count == 0)
-				entity->pipe = NULL;
+		struct media_pad *iter;
+
+		media_entity_for_each_pad(entity, iter) {
+			/* Sanity check for negative stream_count */
+			if (!WARN_ON_ONCE(iter->stream_count <= 0)) {
+				iter->stream_count--;
+				if (iter->stream_count == 0)
+					iter->pipe = NULL;
+			}
 		}
 	}
 
@@ -839,7 +849,7 @@  int __media_entity_setup_link(struct media_link *link, u32 flags)
 {
 	const u32 mask = MEDIA_LNK_FL_ENABLED;
 	struct media_device *mdev;
-	struct media_entity *source, *sink;
+	struct media_pad *source, *sink;
 	int ret = -EBUSY;
 
 	if (link == NULL)
@@ -855,8 +865,8 @@  int __media_entity_setup_link(struct media_link *link, u32 flags)
 	if (link->flags == flags)
 		return 0;
 
-	source = link->source->entity;
-	sink = link->sink->entity;
+	source = link->source;
+	sink = link->sink;
 
 	if (!(link->flags & MEDIA_LNK_FL_DYNAMIC) &&
 	    (source->stream_count || sink->stream_count))
diff --git a/drivers/media/platform/exynos4-is/fimc-isp.c b/drivers/media/platform/exynos4-is/fimc-isp.c
index a77c49b18511..563d07f630bc 100644
--- a/drivers/media/platform/exynos4-is/fimc-isp.c
+++ b/drivers/media/platform/exynos4-is/fimc-isp.c
@@ -223,7 +223,7 @@  static int fimc_isp_subdev_set_fmt(struct v4l2_subdev *sd,
 			}
 		}
 	} else {
-		if (sd->entity.stream_count == 0) {
+		if (sd->entity.pads->stream_count == 0) {
 			if (fmt->pad == FIMC_ISP_SD_PAD_SINK) {
 				struct v4l2_subdev_format format = *fmt;
 
diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c
index fe20af3a7178..56773a0be8d9 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite.c
+++ b/drivers/media/platform/exynos4-is/fimc-lite.c
@@ -1070,7 +1070,7 @@  static int fimc_lite_subdev_set_fmt(struct v4l2_subdev *sd,
 	mutex_lock(&fimc->lock);
 
 	if ((atomic_read(&fimc->out_path) == FIMC_IO_ISP &&
-	    sd->entity.stream_count > 0) ||
+	    sd->entity.pads->stream_count > 0) ||
 	    (atomic_read(&fimc->out_path) == FIMC_IO_DMA &&
 	    vb2_is_busy(&fimc->vb_queue))) {
 		mutex_unlock(&fimc->lock);
diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index a6bb7d9bf75f..4ef623f10a44 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -930,7 +930,7 @@  static int isp_pipeline_is_last(struct media_entity *me)
 	struct isp_pipeline *pipe;
 	struct media_pad *pad;
 
-	if (!me->pipe)
+	if (!me->pads->pipe)
 		return 0;
 	pipe = to_isp_pipeline(me);
 	if (pipe->stream_state == ISP_PIPELINE_STREAM_STOPPED)
diff --git a/drivers/media/platform/omap3isp/ispvideo.c b/drivers/media/platform/omap3isp/ispvideo.c
index 49cde04bfb21..f3bee79cdd85 100644
--- a/drivers/media/platform/omap3isp/ispvideo.c
+++ b/drivers/media/platform/omap3isp/ispvideo.c
@@ -1094,7 +1094,7 @@  isp_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
 	/* Start streaming on the pipeline. No link touching an entity in the
 	 * pipeline can be activated or deactivated once streaming is started.
 	 */
-	pipe = video->video.entity.pipe
+	pipe = video->video.entity.pads->pipe
 	     ? to_isp_pipeline(&video->video.entity) : &video->pipe;
 
 	ret = media_entity_enum_init(&pipe->ent_enum, &video->isp->media_dev);
diff --git a/drivers/media/platform/omap3isp/ispvideo.h b/drivers/media/platform/omap3isp/ispvideo.h
index a0908670c0cf..4c9c5b719ec5 100644
--- a/drivers/media/platform/omap3isp/ispvideo.h
+++ b/drivers/media/platform/omap3isp/ispvideo.h
@@ -100,7 +100,7 @@  struct isp_pipeline {
 };
 
 #define to_isp_pipeline(__e) \
-	container_of((__e)->pipe, struct isp_pipeline, pipe)
+	container_of((__e)->pads->pipe, struct isp_pipeline, pipe)
 
 static inline int isp_pipeline_ready(struct isp_pipeline *pipe)
 {
diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
index cb3025992817..07ec008aacc4 100644
--- a/drivers/media/platform/rcar-vin/rcar-core.c
+++ b/drivers/media/platform/rcar-vin/rcar-core.c
@@ -132,13 +132,17 @@  static int rvin_group_link_notify(struct media_link *link, u32 flags,
 		return 0;
 
 	/*
-	 * Don't allow link changes if any entity in the graph is
-	 * streaming, modifying the CHSEL register fields can disrupt
-	 * running streams.
+	 * Don't allow link changes if any stream in the graph is active as
+	 * modifying the CHSEL register fields can disrupt running streams.
 	 */
-	media_device_for_each_entity(entity, &group->mdev)
-		if (entity->stream_count)
-			return -EBUSY;
+	media_device_for_each_entity(entity, &group->mdev) {
+		struct media_pad *iter;
+
+		media_entity_for_each_pad(entity, iter) {
+			if (iter->stream_count)
+				return -EBUSY;
+		}
+	}
 
 	mutex_lock(&group->lock);
 
diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
index f30dafbdf61c..7994262c9b63 100644
--- a/drivers/media/platform/rcar-vin/rcar-dma.c
+++ b/drivers/media/platform/rcar-vin/rcar-dma.c
@@ -1231,7 +1231,7 @@  static int rvin_set_stream(struct rvin_dev *vin, int on)
 	 */
 	mdev = vin->vdev.entity.graph_obj.mdev;
 	mutex_lock(&mdev->graph_mutex);
-	pipe = sd->entity.pipe ? sd->entity.pipe : &vin->vdev.pipe;
+	pipe = sd->entity.pads->pipe ? sd->entity.pads->pipe : &vin->vdev.pipe;
 	ret = __media_pipeline_start(&vin->vdev.entity, pipe);
 	mutex_unlock(&mdev->graph_mutex);
 	if (ret)
diff --git a/drivers/media/platform/xilinx/xilinx-dma.c b/drivers/media/platform/xilinx/xilinx-dma.c
index 8df3c43aecbe..7fa0467dddde 100644
--- a/drivers/media/platform/xilinx/xilinx-dma.c
+++ b/drivers/media/platform/xilinx/xilinx-dma.c
@@ -403,7 +403,7 @@  static int xvip_dma_start_streaming(struct vb2_queue *vq, unsigned int count)
 	 * Use the pipeline object embedded in the first DMA object that starts
 	 * streaming.
 	 */
-	pipe = dma->video.entity.pipe
+	pipe = dma->video.entity.pads->pipe
 	     ? to_xvip_pipeline(&dma->video.entity) : &dma->pipe;
 
 	ret = media_pipeline_start(&dma->video.entity, &pipe->pipe);
diff --git a/drivers/media/platform/xilinx/xilinx-dma.h b/drivers/media/platform/xilinx/xilinx-dma.h
index 2378bdae57ae..69ced71a5696 100644
--- a/drivers/media/platform/xilinx/xilinx-dma.h
+++ b/drivers/media/platform/xilinx/xilinx-dma.h
@@ -47,7 +47,7 @@  struct xvip_pipeline {
 
 static inline struct xvip_pipeline *to_xvip_pipeline(struct media_entity *e)
 {
-	return container_of(e->pipe, struct xvip_pipeline, pipe);
+	return container_of(e->pads->pipe, struct xvip_pipeline, pipe);
 }
 
 /**
diff --git a/drivers/staging/media/imx/imx-media-utils.c b/drivers/staging/media/imx/imx-media-utils.c
index 5128915a5d6f..04b7c6bdcd85 100644
--- a/drivers/staging/media/imx/imx-media-utils.c
+++ b/drivers/staging/media/imx/imx-media-utils.c
@@ -913,7 +913,7 @@  int imx_media_pipeline_set_stream(struct imx_media_dev *imxmd,
 			__media_pipeline_stop(entity);
 	} else {
 		v4l2_subdev_call(sd, video, s_stream, 0);
-		if (entity->pipe)
+		if (entity->pads->pipe)
 			__media_pipeline_stop(entity);
 	}
 
diff --git a/drivers/staging/media/omap4iss/iss.c b/drivers/staging/media/omap4iss/iss.c
index 085397045b36..4f4573219337 100644
--- a/drivers/staging/media/omap4iss/iss.c
+++ b/drivers/staging/media/omap4iss/iss.c
@@ -543,7 +543,7 @@  static int iss_pipeline_is_last(struct media_entity *me)
 	struct iss_pipeline *pipe;
 	struct media_pad *pad;
 
-	if (!me->pipe)
+	if (!me->pads->pipe)
 		return 0;
 	pipe = to_iss_pipeline(me);
 	if (pipe->stream_state == ISS_PIPELINE_STREAM_STOPPED)
diff --git a/drivers/staging/media/omap4iss/iss_video.c b/drivers/staging/media/omap4iss/iss_video.c
index 9f3ff5a37d90..9d7bf8c85558 100644
--- a/drivers/staging/media/omap4iss/iss_video.c
+++ b/drivers/staging/media/omap4iss/iss_video.c
@@ -870,7 +870,7 @@  iss_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
 	 * Start streaming on the pipeline. No link touching an entity in the
 	 * pipeline can be activated or deactivated once streaming is started.
 	 */
-	pipe = pad->entity->pipe
+	pipe = pad->pipe
 	     ? to_iss_pipeline(pad->entity) : &video->pipe;
 	pipe->external = NULL;
 	pipe->external_rate = 0;
diff --git a/drivers/staging/media/omap4iss/iss_video.h b/drivers/staging/media/omap4iss/iss_video.h
index 526281bf0051..9b8ec27bf87d 100644
--- a/drivers/staging/media/omap4iss/iss_video.h
+++ b/drivers/staging/media/omap4iss/iss_video.h
@@ -91,7 +91,7 @@  struct iss_pipeline {
 };
 
 #define to_iss_pipeline(__e) \
-	container_of((__e)->pipe, struct iss_pipeline, pipe)
+	container_of((__e)->pads->pipe, struct iss_pipeline, pipe)
 
 static inline int iss_pipeline_ready(struct iss_pipeline *pipe)
 {
diff --git a/include/media/media-entity.h b/include/media/media-entity.h
index 52b1a1cab57a..b8f94662526c 100644
--- a/include/media/media-entity.h
+++ b/include/media/media-entity.h
@@ -180,15 +180,24 @@  enum media_pad_signal_type {
  *
  * @graph_obj:	Embedded structure containing the media object common data
  * @entity:	Entity this pad belongs to
+ * @pipe:	Pipeline this pad belongs to.
+ * @stream_count: Stream count for the pad.
  * @index:	Pad index in the entity pads array, numbered from 0 to n
  * @sig_type:	Type of the signal inside a media pad
  * @flags:	Pad flags, as defined in
  *		:ref:`include/uapi/linux/media.h <media_header>`
  *		(seek for ``MEDIA_PAD_FL_*``)
+ * .. note::
+ *
+ *    @stream_count reference count must never be negative, but is a signed
+ *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
+ *    detect reference count bugs that would make them negative.
  */
 struct media_pad {
 	struct media_gobj graph_obj;	/* must be first field in struct */
 	struct media_entity *entity;
+	struct media_pipeline *pipe;
+	int stream_count;
 	u16 index;
 	enum media_pad_signal_type sig_type;
 	unsigned long flags;
@@ -267,9 +276,7 @@  enum media_entity_type {
  * @pads:	Pads array with the size defined by @num_pads.
  * @links:	List of data links.
  * @ops:	Entity operations.
- * @stream_count: Stream count for the entity.
  * @use_count:	Use count for the entity.
- * @pipe:	Pipeline this entity belongs to.
  * @info:	Union with devnode information.  Kept just for backward
  *		compatibility.
  * @info.dev:	Contains device major and minor info.
@@ -282,10 +289,9 @@  enum media_entity_type {
  *
  * .. note::
  *
- *    @stream_count and @use_count reference counts must never be
- *    negative, but are signed integers on purpose: a simple ``WARN_ON(<0)``
- *    check can be used to detect reference count bugs that would make them
- *    negative.
+ *    @use_count reference count must never be negative, but is a signed
+ *    integer on purpose: a simple ``WARN_ON(<0)`` check can be used to
+ *    detect reference count bugs that would make them negative.
  */
 struct media_entity {
 	struct media_gobj graph_obj;	/* must be first field in struct */
@@ -304,11 +310,8 @@  struct media_entity {
 
 	const struct media_entity_operations *ops;
 
-	int stream_count;
 	int use_count;
 
-	struct media_pipeline *pipe;
-
 	union {
 		struct {
 			u32 major;