Re: [PATCH v10 8/8] media: vsp1: Move video configuration to a cached dlb

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Kieran,

Thank you for the patch.

On Thursday, 17 May 2018 20:24:01 EEST Kieran Bingham wrote:
> We are now able to configure a pipeline directly into a local display
> list body. Take advantage of this fact, and create a cacheable body to
> store the configuration of the pipeline in the video object.
> 
> vsp1_video_pipeline_run() is now the last user of the pipe->dl object.
> Convert this function to use the cached video->config body and obtain a
> local display list reference.
> 
> Attach the video->config body to the display list when needed before
> committing to hardware.
> 
> The pipe object is marked as un-configured when resuming from a suspend.

Is this comment still valid ?

> This ensures that when the hardware is reset - our cached configuration
> will be re-attached to the next committed DL.
> 
> Our video DL usage now looks like the below output:
> 
> dl->body0 contains our disposable runtime configuration. Max 41.
> dl_child->body0 is our partition specific configuration. Max 12.
> dl->bodies shows our constant configuration and LUTs.
> 
>   These two are LUT/CLU:
>      * dl->bodies[x]->num_entries 256 / max 256
>      * dl->bodies[x]->num_entries 4914 / max 4914
> 
> Which shows that our 'constant' configuration cache is currently
> utilised to a maximum of 64 entries.
> 
> trace-cmd report | \
>     grep max | sed 's/.*vsp1_dl_list_commit://g' | sort | uniq;
> 
>   dl->body0->num_entries 13 / max 128
>   dl->body0->num_entries 14 / max 128
>   dl->body0->num_entries 16 / max 128
>   dl->body0->num_entries 20 / max 128
>   dl->body0->num_entries 27 / max 128
>   dl->body0->num_entries 34 / max 128
>   dl->body0->num_entries 41 / max 128
>   dl_child->body0->num_entries 10 / max 128
>   dl_child->body0->num_entries 12 / max 128
>   dl->bodies[x]->num_entries 15 / max 128
>   dl->bodies[x]->num_entries 16 / max 128
>   dl->bodies[x]->num_entries 17 / max 128
>   dl->bodies[x]->num_entries 18 / max 128
>   dl->bodies[x]->num_entries 20 / max 128
>   dl->bodies[x]->num_entries 21 / max 128
>   dl->bodies[x]->num_entries 256 / max 256
>   dl->bodies[x]->num_entries 31 / max 128
>   dl->bodies[x]->num_entries 32 / max 128
>   dl->bodies[x]->num_entries 39 / max 128
>   dl->bodies[x]->num_entries 40 / max 128
>   dl->bodies[x]->num_entries 47 / max 128
>   dl->bodies[x]->num_entries 48 / max 128
>   dl->bodies[x]->num_entries 4914 / max 4914
>   dl->bodies[x]->num_entries 55 / max 128
>   dl->bodies[x]->num_entries 56 / max 128
>   dl->bodies[x]->num_entries 63 / max 128
>   dl->bodies[x]->num_entries 64 / max 128
> 
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> ---
> v10:
>  - Removed pipe->configured flag, and use
>    pipe->state == VSP1_PIPELINE_STOPPED instead.
> 
> v8:
>  - Fix comments
>  - Rename video->pipe_config -> video->stream_config
> 
> v4:
>  - Adjust pipe configured flag to be reset on resume rather than suspend
>  - rename dl_child, dl_next
> 
> v3:
>  - 's/fragment/body/', 's/fragments/bodies/'
>  - video dlb cache allocation increased from 2 to 3 dlbs
> 
>  drivers/media/platform/vsp1/vsp1_pipe.h  |  3 +-
>  drivers/media/platform/vsp1/vsp1_video.c | 67 +++++++++++++++----------
>  drivers/media/platform/vsp1/vsp1_video.h |  2 +-
>  3 files changed, 43 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/media/platform/vsp1/vsp1_pipe.h
> b/drivers/media/platform/vsp1/vsp1_pipe.h index e00010693eef..be6ecab3cbed
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_pipe.h
> +++ b/drivers/media/platform/vsp1/vsp1_pipe.h
> @@ -102,7 +102,6 @@ struct vsp1_partition {
>   * @uds: UDS entity, if present
>   * @uds_input: entity at the input of the UDS, if the UDS is present
>   * @entities: list of entities in the pipeline
> - * @dl: display list associated with the pipeline
>   * @partitions: The number of partitions used to process one frame
>   * @partition: The current partition for configuration to process
>   * @part_table: The pre-calculated partitions used by the pipeline
> @@ -139,8 +138,6 @@ struct vsp1_pipeline {
>  	 */
>  	struct list_head entities;
> 
> -	struct vsp1_dl_list *dl;
> -
>  	unsigned int partitions;
>  	struct vsp1_partition *partition;
>  	struct vsp1_partition *part_table;
> diff --git a/drivers/media/platform/vsp1/vsp1_video.c
> b/drivers/media/platform/vsp1/vsp1_video.c index 72f29773eb1c..f2bc26d28396
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_video.c
> +++ b/drivers/media/platform/vsp1/vsp1_video.c
> @@ -390,44 +390,48 @@ static void vsp1_video_pipeline_run_partition(struct
> vsp1_pipeline *pipe, static void vsp1_video_pipeline_run(struct
> vsp1_pipeline *pipe)
>  {
>  	struct vsp1_device *vsp1 = pipe->output->entity.vsp1;
> +	struct vsp1_video *video = pipe->output->video;
>  	struct vsp1_entity *entity;
>  	struct vsp1_dl_body *dlb;
> +	struct vsp1_dl_list *dl;
>  	unsigned int partition;
> 
> -	if (!pipe->dl)
> -		pipe->dl = vsp1_dl_list_get(pipe->output->dlm);
> +	dl = vsp1_dl_list_get(pipe->output->dlm);
> +
> +	/* Attach our pipe configuration to fully initialise the hardware. */

I'd expand this to explain that the cached stream configuration needs to be 
applied only if the VSP is uninitialized. How about

	/*
	 * If the VSP hardware isn't configured yet (which occurs either when 
	 * processing the first frame or after a system suspend/resume), add the 
	 * cached stream configuration to the display list to perform a full
	 * initialisation.
	 */

> +	if (pipe->state == VSP1_PIPELINE_STOPPED)
> +		vsp1_dl_list_add_body(dl, video->stream_config);

The pipeline state is set to VSP1_PIPELINE_STOPPED at the end of every frame 
in vsp1_video_pipeline_frame_end(). Do you really want to fully reconfigure 
the hardware for every frame ?

> -	dlb = vsp1_dl_list_get_body0(pipe->dl);
> +	dlb = vsp1_dl_list_get_body0(dl);
> 
>  	list_for_each_entry(entity, &pipe->entities, list_pipe)
> -		vsp1_entity_configure_frame(entity, pipe, pipe->dl, dlb);
> +		vsp1_entity_configure_frame(entity, pipe, dl, dlb);
> 
>  	/* Run the first partition. */
> -	vsp1_video_pipeline_run_partition(pipe, pipe->dl, 0);
> +	vsp1_video_pipeline_run_partition(pipe, dl, 0);
> 
>  	/* Process consecutive partitions as necessary. */
>  	for (partition = 1; partition < pipe->partitions; ++partition) {
> -		struct vsp1_dl_list *dl;
> +		struct vsp1_dl_list *dl_next;
> 
> -		dl = vsp1_dl_list_get(pipe->output->dlm);
> +		dl_next = vsp1_dl_list_get(pipe->output->dlm);
> 
>  		/*
>  		 * An incomplete chain will still function, but output only
>  		 * the partitions that had a dl available. The frame end
>  		 * interrupt will be marked on the last dl in the chain.
>  		 */
> -		if (!dl) {
> +		if (!dl_next) {
>  			dev_err(vsp1->dev, "Failed to obtain a dl list. Frame will be
> incomplete\n"); break;
>  		}
> 
> -		vsp1_video_pipeline_run_partition(pipe, dl, partition);
> -		vsp1_dl_list_add_chain(pipe->dl, dl);
> +		vsp1_video_pipeline_run_partition(pipe, dl_next, partition);
> +		vsp1_dl_list_add_chain(dl, dl_next);
>  	}
> 
>  	/* Complete, and commit the head display list. */
> -	vsp1_dl_list_commit(pipe->dl, false);
> -	pipe->dl = NULL;
> +	vsp1_dl_list_commit(dl, false);
> 
>  	vsp1_pipeline_run(pipe);
>  }
> @@ -790,8 +794,8 @@ static void vsp1_video_buffer_queue(struct vb2_buffer
> *vb)
> 
>  static int vsp1_video_setup_pipeline(struct vsp1_pipeline *pipe)
>  {
> +	struct vsp1_video *video = pipe->output->video;
>  	struct vsp1_entity *entity;
> -	struct vsp1_dl_body *dlb;
>  	int ret;
> 
>  	/* Determine this pipelines sizes for image partitioning support. */
> @@ -799,14 +803,6 @@ static int vsp1_video_setup_pipeline(struct
> vsp1_pipeline *pipe) if (ret < 0)
>  		return ret;
> 
> -	/* Prepare the display list. */
> -	pipe->dl = vsp1_dl_list_get(pipe->output->dlm);
> -	if (!pipe->dl)
> -		return -ENOMEM;
> -
> -	/* Retrieve the default DLB from the list. */
> -	dlb = vsp1_dl_list_get_body0(pipe->dl);
> -
>  	if (pipe->uds) {
>  		struct vsp1_uds *uds = to_uds(&pipe->uds->subdev);
> 
> @@ -828,9 +824,16 @@ static int vsp1_video_setup_pipeline(struct
> vsp1_pipeline *pipe) }
>  	}
> 
> +	/* Obtain a clean body from our pool. */
> +	video->stream_config = vsp1_dl_body_get(video->dlbs);
> +	if (!video->stream_config)
> +		return -ENOMEM;
> +
> +	/* Configure the entities into our cached pipe configuration. */

I would group the two comments to better explain what we're doing here. How 
about something like this ?

	/*
	 * Compute and cache the stream configuration for the pipeline. First
	 * create a display list body to hold the configuration, and then write
	 * routing and stream configuration for each entity in the body. The
	 * body will be added to the display list by vsp1_video_pipeline_run()
	 * when the pipeline needs to be fully reconfigured.
	 */

>  	list_for_each_entry(entity, &pipe->entities, list_pipe) {
> -		vsp1_entity_route_setup(entity, pipe, dlb);
> -		vsp1_entity_configure_stream(entity, pipe, dlb);
> +		vsp1_entity_route_setup(entity, pipe, video->stream_config);
> +		vsp1_entity_configure_stream(entity, pipe,
> +					     video->stream_config);
>  	}
> 
>  	return 0;
> @@ -842,6 +845,9 @@ static void vsp1_video_cleanup_pipeline(struct
> vsp1_pipeline *pipe) struct vsp1_vb2_buffer *buffer;
>  	unsigned long flags;
> 
> +	/* Release any cached configuration. */
> +	vsp1_dl_body_put(video->stream_config);
> +
>  	/* Remove all buffers from the IRQ queue. */
>  	spin_lock_irqsave(&video->irqlock, flags);
>  	list_for_each_entry(buffer, &video->irqqueue, queue)
> @@ -918,9 +924,6 @@ static void vsp1_video_stop_streaming(struct vb2_queue
> *vq) ret = vsp1_pipeline_stop(pipe);
>  		if (ret == -ETIMEDOUT)
>  			dev_err(video->vsp1->dev, "pipeline stop timeout\n");
> -
> -		vsp1_dl_list_put(pipe->dl);
> -		pipe->dl = NULL;
>  	}
>  	mutex_unlock(&pipe->lock);
> 
> @@ -1240,6 +1243,16 @@ struct vsp1_video *vsp1_video_create(struct
> vsp1_device *vsp1, goto error;
>  	}
> 
> +	/*
> +	 * Utilise a body pool to cache the constant configuration of the
> +	 * pipeline object.
> +	 */
> +	video->dlbs = vsp1_dl_body_pool_create(vsp1, 3, 128, 0);

Why do we preallocate three bodies here, don't we need just one ?

I'm also wondering whether we could reuse the WPF body pool instead of 
creating a new one.

> +	if (!video->dlbs) {
> +		ret = -ENOMEM;
> +		goto error;
> +	}
> +
>  	return video;
> 
>  error:
> @@ -1249,6 +1262,8 @@ struct vsp1_video *vsp1_video_create(struct
> vsp1_device *vsp1,
> 
>  void vsp1_video_cleanup(struct vsp1_video *video)
>  {
> +	vsp1_dl_body_pool_destroy(video->dlbs);
> +
>  	if (video_is_registered(&video->video))
>  		video_unregister_device(&video->video);
> 
> diff --git a/drivers/media/platform/vsp1/vsp1_video.h
> b/drivers/media/platform/vsp1/vsp1_video.h index 75a5a65c66fe..77bbfb4a5b54
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_video.h
> +++ b/drivers/media/platform/vsp1/vsp1_video.h
> @@ -39,6 +39,8 @@ struct vsp1_video {
> 
>  	struct mutex lock;
> 
> +	struct vsp1_dl_body_pool *dlbs;
> +	struct vsp1_dl_body *stream_config;
>  	unsigned int pipe_index;
> 
>  	struct vb2_queue queue;

-- 
Regards,

Laurent Pinchart