From c907fcdca5bd0b5e948a98e2158910d32f0f6154 Mon Sep 17 00:00:00 2001
From: Dominic Clark <mrdomclark@gmail.com>
Date: Wed, 6 Feb 2019 18:25:11 +0000
Subject: [PATCH] Don't let silent instruments wake up sleeping effects (#4792)

---
 src/core/audio/AudioPort.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/core/audio/AudioPort.cpp b/src/core/audio/AudioPort.cpp
index 868f9f64f..5b2ff7f95 100644
--- a/src/core/audio/AudioPort.cpp
+++ b/src/core/audio/AudioPort.cpp
@@ -119,7 +119,9 @@ void AudioPort::doProcessing()
 	{
 		if( ph->buffer() )
 		{
-			if( ph->usesBuffer() )
+			if( ph->usesBuffer()
+				&& ( ph->type() == PlayHandle::TypeNotePlayHandle
+					|| !MixHelpers::isSilent( ph->buffer(), fpp ) ) )
 			{
 				m_bufferUsage = true;
 				MixHelpers::add( m_portBuffer, ph->buffer(), fpp );