[PATCH 3/6] alsa-lib: pcm:dshare enable silence

[PATCH 3/6] alsa-lib: pcm:dshare enable silence

[sutar.mounesh]

From: Alexander Jahn <ajahn@de.adit-jv.com>

This issue depends on system load - if the process using dshare is scheduled
fast enough, then there is no noise. A delay of e.g >~2ms produces hearable noise.

Reproduction with instrumented aplay(sleep every 100th period for a given time):
During the sleep time of 2000000us (2s) the hardware plays old samples in a
loop before xrun is detected and recovered after the sleep.
This is resolved by placing it in silence, in case of dshare plugin.

Signed-off-by: Alexander Jahn <ajahn@de.adit-jv.com>
Signed-off-by: Andreas Pape <apape@de.adit-jv.com>

diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c
index 4234d66..779845c 100644
--- a/src/pcm/pcm_direct.c
+++ b/src/pcm/pcm_direct.c
@@ -1240,7 +1240,7 @@ int snd_pcm_direct_initialize_slave(snd_pcm_direct_t *dmix, snd_pcm_t *spcm, str
 		return ret;
 	}
 
-	if (dmix->type != SND_PCM_TYPE_DMIX)
+	if ((dmix->type != SND_PCM_TYPE_DMIX)&&(dmix->type != SND_PCM_TYPE_DSHARE))
 		goto __skip_silencing;
 
 	ret = snd_pcm_sw_params_set_silence_threshold(spcm, &sw_params, 0);
-- 
1.7.9.5

Re: [PATCH 3/6] alsa-lib: pcm:dshare enable silence

[Takashi Iwai]

On Fri, 30 Dec 2016 07:29:11 +0100,
sutar.mounesh@gmail.com wrote:
> 
> From: Alexander Jahn <ajahn@de.adit-jv.com>
> 
> This issue depends on system load - if the process using dshare is scheduled
> fast enough, then there is no noise. A delay of e.g >~2ms produces hearable noise.
> 
> Reproduction with instrumented aplay(sleep every 100th period for a given time):
> During the sleep time of 2000000us (2s) the hardware plays old samples in a
> loop before xrun is detected and recovered after the sleep.
> This is resolved by placing it in silence, in case of dshare plugin.
> 
> Signed-off-by: Alexander Jahn <ajahn@de.adit-jv.com>
> Signed-off-by: Andreas Pape <apape@de.adit-jv.com>

Applied this one with a slight coding style fix.  Thanks.


Takashi


> 
> diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c
> index 4234d66..779845c 100644
> --- a/src/pcm/pcm_direct.c
> +++ b/src/pcm/pcm_direct.c
> @@ -1240,7 +1240,7 @@ int snd_pcm_direct_initialize_slave(snd_pcm_direct_t *dmix, snd_pcm_t *spcm, str
>  		return ret;
>  	}
>  
> -	if (dmix->type != SND_PCM_TYPE_DMIX)
> +	if ((dmix->type != SND_PCM_TYPE_DMIX)&&(dmix->type != SND_PCM_TYPE_DSHARE))
>  		goto __skip_silencing;
>  
>  	ret = snd_pcm_sw_params_set_silence_threshold(spcm, &sw_params, 0);
> -- 
> 1.7.9.5
>