[Sound-open-firmware] [PATCH 21/25] mixer: add R/W pointer check for mixer_copy()

[Liam Girdwood]

On Tue, 2017-02-07 at 22:03 +0800, Keyon Jie wrote:
> We should only copy when there is data, as we are using pulling
> mode, should sink side should have free space always, we check
> each source->avail and copy only some bytes when avail < period
> size.
> 
> Signed-off-by: Keyon Jie <yang.jie at linux.intel.com>
> ---
>  src/audio/mixer.c | 23 +++++++++++++++++++++--
>  1 file changed, 21 insertions(+), 2 deletions(-)
> 
> diff --git a/src/audio/mixer.c b/src/audio/mixer.c
> index 57669a7..2d021b7 100644
> --- a/src/audio/mixer.c
> +++ b/src/audio/mixer.c
> @@ -214,7 +214,7 @@ static int mixer_copy(struct comp_dev *dev)
>  {
>  	struct mixer_data *md = comp_get_drvdata(dev);
>  	struct comp_buffer *sink, *sources[5], *source;
> -	uint32_t i = 0, cframes = PLAT_INT_PERIOD_FRAMES;
> +	uint32_t i = 0, mixing_num, cframes = PLAT_INT_PERIOD_FRAMES;
>  	struct list_item * blist;
>  
>  	trace_mixer("Mix");
> @@ -227,13 +227,31 @@ static int mixer_copy(struct comp_dev *dev)
>  			sources[i++] = source;
>  	}
>  
> +	mixing_num = i;

number of sources or frames ?

num_mix_sources or num_mix_frames.

> +
>  	sink = list_first_item(&dev->bsink_list, struct comp_buffer, source_list);
>  
> +	for(i = 0; i < mixing_num; i++) {
> +		if (sources[i]->avail < cframes * sources[i]->params.frame_size)
> +			cframes = sources[i]->avail /sources[i]->params.frame_size;
> +	}
> +	if (sink->free < cframes * sink->params.frame_size)
> +		cframes = sink->free /sink->params.frame_size;
> +
> +	if (mixing_num == 0)
> +		cframes = 0;
> +
> +	/* no frames to mix */
> +	if (cframes == 0) {
> +		trace_value(cframes);
> +		return 0;
> +	}
> +
>  	/* mix streams */
>  	md->mix_func(dev, sink, sources, i, cframes);
>  
>  	/* update buffer pointers for overflow */
> -	for(; i > 0; i--) {
> +	for(i = mixing_num; i > 0; i--) {
>  		if (sources[i-1]->r_ptr >= sources[i-1]->end_addr)
>  			sources[i-1]->r_ptr = sources[i-1]->addr;
>  		comp_update_buffer_consume(sources[i-1]);
> @@ -260,6 +278,7 @@ static int mixer_reset(struct comp_dev *dev)
>  			return 1; /* should not reset the downstream components */
>  	}
>  
> +	dev->state = COMP_STATE_INIT;
>  	return 0;
>  }
>