[alsa-devel] [PATCH v9 4/7] ASoC: hdmi-codec: Add audio abort() callback for video side to use

[Arnaud Pouliquen]

On 03/31/2016 03:36 PM, Jyri Sarha wrote:
> Add audio abort() callback, that is provided at audio stream start,
> for video side. This is for video side to use in case there is a
> pressing need to tear down the audio playback for some reason.
> 
> Signed-off-by: Jyri Sarha <jsarha at ti.com>
> ---
>  include/sound/hdmi-codec.h    |  8 ++++++--
>  sound/soc/codecs/hdmi-codec.c | 20 +++++++++++++++++++-
>  2 files changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/include/sound/hdmi-codec.h b/include/sound/hdmi-codec.h
> index fc3a481..15fe70f 100644
> --- a/include/sound/hdmi-codec.h
> +++ b/include/sound/hdmi-codec.h
> @@ -55,10 +55,14 @@ struct hdmi_codec_params {
>  
>  struct hdmi_codec_ops {
>  	/*
> -	 * Called when ASoC starts an audio stream setup.
> +	 * Called when ASoC starts an audio stream setup. The call
> +	 * provides an audio abort callback for stoping an ongoing
stopping
> +	 * stream from video side driver if the HDMI audio becomes
> +	 * unavailable.
>  	 * Optional
>  	 */
> -	int (*audio_startup)(struct device *dev);
> +	int (*audio_startup)(struct device *dev,
> +			     void (*abort_cb)(struct device *dev));
>  
>  	/*
>  	 * Configures HDMI-encoder for audio stream.
> diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
> index b46b8ed..35151a4 100644
> --- a/sound/soc/codecs/hdmi-codec.c
> +++ b/sound/soc/codecs/hdmi-codec.c
> @@ -47,6 +47,23 @@ enum {
>  	DAI_ID_SPDIF,
>  };
>  
> +static void hdmi_codec_abort(struct device *dev)
> +{
> +	struct hdmi_codec_priv *hcp = dev_get_drvdata(dev);
> +
> +	dev_dbg(dev, "%s()\n", __func__);
> +
> +	mutex_lock(&hcp->current_stream_lock);
> +	if (hcp->current_stream && hcp->current_stream->runtime &&
> +	    snd_pcm_running(hcp->current_stream)) {
> +		dev_info(dev, "HDMI audio playback aborted\n");
> +		snd_pcm_stream_lock_irq(hcp->current_stream);
> +		snd_pcm_stop(hcp->current_stream, SNDRV_PCM_STATE_DISCONNECTED);
> +		snd_pcm_stream_unlock_irq(hcp->current_stream);
> +	}
> +	mutex_unlock(&hcp->current_stream_lock);
> +}
> +
still not understand the need... i can not find a use case that
justifies it.
As example, in case of HDMI plug/unplug i would not want that audio
stream is stopped (live playback). From my point of view this should be
a decision from user.
But as it is optional, I'm ok if need is justified.

>  static int hdmi_codec_new_stream(struct snd_pcm_substream *substream,
>  				 struct snd_soc_dai *dai)
>  {
> @@ -78,7 +95,8 @@ static int hdmi_codec_startup(struct snd_pcm_substream *substream,
>  		return ret;
>  
>  	if (hcp->hcd.ops->audio_startup) {
> -		ret = hcp->hcd.ops->audio_startup(dai->dev->parent);
> +		ret = hcp->hcd.ops->audio_startup(dai->dev->parent,
> +						  hdmi_codec_abort);
>  		if (ret) {
>  			mutex_lock(&hcp->current_stream_lock);
>  			hcp->current_stream = NULL;
>