Re: [PATCH v4 3/4] v4l: vsp1: Repair suspend resume operations for video pipelines

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

Hi Kieran,

Thank you for the patch.

On Friday 06 Jan 2017 12:15:30 Kieran Bingham wrote:
> When a suspend/resume action is taken, the pipeline is reset and never
> reconfigured.
> 
> To correct this, we establish a new flag pipe->configured and utilise
> this to establish when we write a full configuration set to the current
> display list.

As discussed face to face, I think a better approach would be to cache the 
display list instead of recomputing it a resume time. However, given that this 
will require more work, I could be convinced to merge this patch in the 
meantime. Let's check in a couple of weeks whether we will have moved forward 
with display list caching in time for v4.12, and merge this patch otherwise.

> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> ---
>  drivers/media/platform/vsp1/vsp1_drv.c   |  4 ++-
>  drivers/media/platform/vsp1/vsp1_pipe.c  |  1 +-
>  drivers/media/platform/vsp1/vsp1_pipe.h  |  2 +-
>  drivers/media/platform/vsp1/vsp1_video.c | 56 ++++++++++---------------
>  4 files changed, 31 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/media/platform/vsp1/vsp1_drv.c
> b/drivers/media/platform/vsp1/vsp1_drv.c index aa237b48ad55..d596cdead1c1
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_drv.c
> +++ b/drivers/media/platform/vsp1/vsp1_drv.c
> @@ -413,6 +413,7 @@ static int vsp1_create_entities(struct vsp1_device
> *vsp1)
> 
>  int vsp1_reset_wpf(struct vsp1_device *vsp1, unsigned int index)
>  {
> +	struct vsp1_rwpf *wpf = vsp1->wpf[index];
>  	unsigned int timeout;
>  	u32 status;
> 
> @@ -429,6 +430,9 @@ int vsp1_reset_wpf(struct vsp1_device *vsp1, unsigned
> int index) usleep_range(1000, 2000);
>  	}
> 
> +	if (wpf->pipe)
> +		wpf->pipe->configured = false;
> +
>  	if (!timeout) {
>  		dev_err(vsp1->dev, "failed to reset wpf.%u\n", index);
>  		return -ETIMEDOUT;
> diff --git a/drivers/media/platform/vsp1/vsp1_pipe.c
> b/drivers/media/platform/vsp1/vsp1_pipe.c index 280ba0804699..c568db193fba
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_pipe.c
> +++ b/drivers/media/platform/vsp1/vsp1_pipe.c
> @@ -216,6 +216,7 @@ void vsp1_pipeline_init(struct vsp1_pipeline *pipe)
> 
>  	INIT_LIST_HEAD(&pipe->entities);
>  	pipe->state = VSP1_PIPELINE_STOPPED;
> +	pipe->configured = false;
>  }
> 
>  /* Must be called with the pipe irqlock held. */
> diff --git a/drivers/media/platform/vsp1/vsp1_pipe.h
> b/drivers/media/platform/vsp1/vsp1_pipe.h index ac4ad2655551..fff122b4874d
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_pipe.h
> +++ b/drivers/media/platform/vsp1/vsp1_pipe.h
> @@ -61,6 +61,7 @@ enum vsp1_pipeline_state {
>   * @pipe: the media pipeline
>   * @irqlock: protects the pipeline state
>   * @state: current state
> + * @configured: true if the pipeline has been set up for video streaming
>   * @wq: wait queue to wait for state change completion
>   * @frame_end: frame end interrupt handler
>   * @lock: protects the pipeline use count and stream count
> @@ -86,6 +87,7 @@ struct vsp1_pipeline {
> 
>  	spinlock_t irqlock;
>  	enum vsp1_pipeline_state state;
> +	bool configured;
>  	wait_queue_head_t wq;
> 
>  	void (*frame_end)(struct vsp1_pipeline *pipe);
> diff --git a/drivers/media/platform/vsp1/vsp1_video.c
> b/drivers/media/platform/vsp1/vsp1_video.c index 938ecc2766ed..414303442e7c
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_video.c
> +++ b/drivers/media/platform/vsp1/vsp1_video.c
> @@ -355,18 +355,14 @@ static void vsp1_video_frame_end(struct vsp1_pipeline
> *pipe, pipe->buffers_ready |= 1 << video->pipe_index;
>  }
> 
> -static int vsp1_video_setup_pipeline(struct vsp1_pipeline *pipe)
> +static int vsp1_video_setup_pipeline(struct vsp1_pipeline *pipe,
> +				     struct vsp1_dl_list *dl)
>  {
>  	struct vsp1_entity *entity;
> 
>  	/* Determine this pipelines sizes for image partitioning support. */
>  	vsp1_video_pipeline_setup_partitions(pipe);
> 
> -	/* Prepare the display list. */
> -	pipe->dl = vsp1_dl_list_get(pipe->output->dlm);
> -	if (!pipe->dl)
> -		return -ENOMEM;
> -
>  	if (pipe->uds) {
>  		struct vsp1_uds *uds = to_uds(&pipe->uds->subdev);
> 
> @@ -386,13 +382,15 @@ static int vsp1_video_setup_pipeline(struct
> vsp1_pipeline *pipe) }
> 
>  	list_for_each_entry(entity, &pipe->entities, list_pipe) {
> -		vsp1_entity_route_setup(entity, pipe->dl);
> +		vsp1_entity_route_setup(entity, dl);
> 
>  		if (entity->ops->configure)
> -			entity->ops->configure(entity, pipe, pipe->dl,
> +			entity->ops->configure(entity, pipe, dl,
>  					       VSP1_ENTITY_PARAMS_INIT);
>  	}
> 
> +	pipe->configured = true;
> +
>  	return 0;
>  }
> 
> @@ -415,9 +413,16 @@ static void vsp1_video_pipeline_run(struct
> vsp1_pipeline *pipe) {
>  	struct vsp1_device *vsp1 = pipe->output->entity.vsp1;
>  	struct vsp1_entity *entity;
> +	struct vsp1_dl_list *dl;
> 
> -	if (!pipe->dl)
> -		pipe->dl = vsp1_dl_list_get(pipe->output->dlm);
> +	dl = vsp1_dl_list_get(pipe->output->dlm);
> +	if (!dl) {
> +		dev_err(vsp1->dev, "Failed to obtain a dl list\n");
> +		return;
> +	}
> +
> +	if (!pipe->configured)
> +		vsp1_video_setup_pipeline(pipe, dl);
> 
>  	/*
>  	 * Start with the runtime parameters as the configure operation can
> @@ -426,45 +431,43 @@ static void vsp1_video_pipeline_run(struct
> vsp1_pipeline *pipe) */
>  	list_for_each_entry(entity, &pipe->entities, list_pipe) {
>  		if (entity->ops->configure)
> -			entity->ops->configure(entity, pipe, pipe->dl,
> +			entity->ops->configure(entity, pipe, dl,
>  					       VSP1_ENTITY_PARAMS_RUNTIME);
>  	}
> 
>  	/* Run the first partition */
>  	pipe->current_partition = 0;
> -	vsp1_video_pipeline_run_partition(pipe, pipe->dl);
> +	vsp1_video_pipeline_run_partition(pipe, dl);
> 
>  	/* Process consecutive partitions as necessary */
>  	for (pipe->current_partition = 1;
>  	     pipe->current_partition < pipe->partitions;
>  	     pipe->current_partition++) {
> -		struct vsp1_dl_list *dl;
> +		struct vsp1_dl_list *child;
> 
>  		/*
>  		 * Partition configuration operations will utilise
>  		 * the pipe->current_partition variable to determine
>  		 * the work they should complete.
>  		 */
> -		dl = vsp1_dl_list_get(pipe->output->dlm);
> +		child = 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 (!child) {
>  			dev_err(vsp1->dev, "Failed to obtain a dl list. Frame 
will be
> incomplete\n"); break;
>  		}
> 
> -		vsp1_video_pipeline_run_partition(pipe, dl);
> -		vsp1_dl_list_add_chain(pipe->dl, dl);
> +		vsp1_video_pipeline_run_partition(pipe, child);
> +		vsp1_dl_list_add_chain(dl, child);
>  	}
> 
>  	/* Complete, and commit the head display list. */
> -	vsp1_dl_list_commit(pipe->dl);
> -	pipe->dl = NULL;
> -
> +	vsp1_dl_list_commit(dl);
>  	vsp1_pipeline_run(pipe);
>  }
> 
> @@ -799,18 +802,10 @@ static int vsp1_video_start_streaming(struct vb2_queue
> *vq, unsigned int count) struct vsp1_pipeline *pipe = video->rwpf->pipe;
>  	bool start_pipeline = false;
>  	unsigned long flags;
> -	int ret;
> 
>  	mutex_lock(&pipe->lock);
> -	if (pipe->stream_count == pipe->num_inputs) {
> -		ret = vsp1_video_setup_pipeline(pipe);
> -		if (ret < 0) {
> -			mutex_unlock(&pipe->lock);
> -			return ret;
> -		}
> -
> +	if (pipe->stream_count == pipe->num_inputs)
>  		start_pipeline = true;
> -	}
> 
>  	pipe->stream_count++;
>  	mutex_unlock(&pipe->lock);
> @@ -855,9 +850,6 @@ 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);

-- 
Regards,

Laurent Pinchart