[alsa-devel] [PATCH v3 6/6] pcm:plug: save converter config

[Takashi Sakamoto]

Hi,

On Mar 3 2017 18:58, sutar.mounesh at gmail.com wrote:
> From: Andreas Pape <apape at de.adit-jv.com>
>
> Passed config is freed after call to open, thus it is invalid when
> trying to extract the converter name. So config entry is saved
> for later usage.
>
> Signed-off-by: Andreas Pape <apape at de.adit-jv.com>
> Signed-off-by: Mounesh Sutar <sutar.mounesh at gmail.com>

I agree with your idea to fix this issue. However...

> diff --git a/src/pcm/pcm_plug.c b/src/pcm/pcm_plug.c
> index 266707b..c643278 100644
> --- a/src/pcm/pcm_plug.c
> +++ b/src/pcm/pcm_plug.c
> @@ -64,6 +64,10 @@ static int snd_pcm_plug_close(snd_pcm_t *pcm)
>  	snd_pcm_plug_t *plug = pcm->private_data;
>  	int err, result = 0;
>  	free(plug->ttable);
> +	if (plug->rate_converter) {
> +		snd_config_delete((snd_config_t*)plug->rate_converter);
> +		plug->rate_converter = NULL;
> +	}
>  	assert(plug->gen.slave == plug->req_slave);
>  	if (plug->gen.close_slave) {
>  		snd_pcm_unlink_hw_ptr(pcm, plug->req_slave);
> @@ -1108,7 +1112,14 @@ int snd_pcm_plug_open(snd_pcm_t **pcmp,
>  	plug->sformat = sformat;
>  	plug->schannels = schannels;
>  	plug->srate = srate;
> -	plug->rate_converter = rate_converter;
> +	if (rate_converter) {
> +		if ((err = snd_config_copy((snd_config_t**)&plug->rate_converter,
> +					   (snd_config_t *)rate_converter)) < 0) {
> +			free(plug);
> +			return err;
> +		}
> +	}
> +

The 'rate_converter' member is not referred in a call of following 
snd_pcm_new(), thus the copy operation can be postponed enough later 
than the call. This dedicates code simplicity, I think.

>  	plug->gen.slave = plug->req_slave = slave;
>  	plug->gen.close_slave = close_slave;
>  	plug->route_policy = route_policy;
> @@ -1119,6 +1130,10 @@ int snd_pcm_plug_open(snd_pcm_t **pcmp,
>  	
>  	err = snd_pcm_new(&pcm, SND_PCM_TYPE_PLUG, name, slave->stream, slave->mode);
>  	if (err < 0) {
> +		if (plug->rate_converter) {
> +			snd_config_delete((snd_config_t*)plug->rate_converter);
> +			plug->rate_converter = NULL;
> +		}
>  		free(plug);
>  		return err;
>  	}


Thanks

Takashi Sakamoto