sound: workaround softvol channels initialization by running dummy aplay and arecord

postplug.d/35sound

@@ -93,7 +93,11 @@ if [ "$SOUND_FORCE_RESCAN" != "on" -a "$SOUND_FORCE_RESCAN" != "1" ]; then
    fi
 fi
 
-echo "$SOUND_DEV" > $postpluglibdir/sound.cache
+# WORKAROUND: custom softvol controls are not actived until a play/rec is done
+#             this also triggers kmix crash problem at first boot
+aplay -q -d1 < /dev/zero
+arecord -q -d1 > /dev/null
+
 for c in /proc/asound/card[0-9]*; do
    id=`cat $c/id`
    codec=`grep Codec: $c/codec* 2>/dev/null | head -n1`
@@ -106,7 +110,5 @@ if [ -x /usr/sbin/alsactl ]; then
    logmsg "$me" $"saving the mixer setup (/var/lib/sound/asound.state)"
    /usr/sbin/alsactl store > /dev/null
 fi
-
 echo "$SOUND_DEV" > $postpluglibdir/sound.cache
-
 exit 0