File 0004-pcm-dshare-enable-silence.patch of Package alsa.openSUSE_Leap_42.2_Update

From 8eeee1ab7d7db3110b7b3bb31cfb989304dced94 Mon Sep 17 00:00:00 2001
From: Alexander Jahn <ajahn@de.adit-jv.com>
Date: Fri, 30 Dec 2016 11:59:11 +0530
Subject: [PATCH 04/43] pcm: dshare: enable silence

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 src/pcm/pcm_direct.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/src/pcm/pcm_direct.c
+++ b/src/pcm/pcm_direct.c
@@ -1161,7 +1161,8 @@ int snd_pcm_direct_initialize_slave(snd_
 		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);