diff --git a/amp/src/aal/sound/sound_api.c b/amp/src/aal/sound/sound_api.c
index 27c374c..ac3b5dd 100755
--- a/amp/src/aal/sound/sound_api.c
+++ b/amp/src/aal/sound/sound_api.c
@@ -3067,6 +3067,7 @@ HRESULT AMP_SND_SetStreamVolumeIndB(AMP_IN HANDLE hStream, AMP_IN float fVolume)
     SND_STRM *pStream = 0;
     UINT32 uiVolume = 0;
     AMP_APP_PARAST stAppParam;
+    AMP_SOUND_DRIVER *pSndDrv = g_stSndDriver;
 
     SND_API_ENTER();
     SNDDRV_CHECKVALID();
@@ -3097,6 +3098,7 @@ HRESULT AMP_SND_SetStreamVolumeIndB(AMP_IN HANDLE hStream, AMP_IN float fVolume)
         (pStream->PeerPortConn.hInterHandle == SOUND_PORTID_PASSTHROUGH &&
         pStream->PeerPortConn.uiFlags == HDMI_PATH))
     {
+        MV_OSAL_Mutex_Lock(pSndDrv->hDrvMutex);
 #ifdef CONFIG_AMP_AUDIO_MUTE_PT_FOR_STREAM
         SNDLOGD("HDMI pass through case, stream volume is set to AOUT!\n");
         AMP_RPC(rc, AMP_SNDSINK_SetAoutStreamVolume, pStream->hSndSinkComp,
@@ -3109,6 +3111,11 @@ HRESULT AMP_SND_SetStreamVolumeIndB(AMP_IN HANDLE hStream, AMP_IN float fVolume)
 #if 1  //tony debug
         pStream->uiStreamVolume = uiVolume;
 #endif 
+        if( pStream->uiStreamVolume != 0 ){
+            AMP_RPC(rc, AMP_SNDSINK_SetAoutStreamVolume, pStream->hSndSinkComp, HDMI_PATH, 0x40000000L);
+        }
+        MV_OSAL_Mutex_Unlock(pSndDrv->hDrvMutex);
+
         return rc;
     }
 
@@ -3482,7 +3489,6 @@ HRESULT AMP_SND_SetStreamMute(AMP_IN HANDLE hStream, AMP_IN BOOL bMute)
     SNDSTRM_CHECKVALID(hStream);
     pStream = (SND_STRM *)hStream;
     stAppParam._d = AMP_APP_PARAIDX_VOLUME;
-
     
     if((pStream->PeerPortConn.ePeerType == AMP_PORT_AREN_OUT_SPDIF)||
         (pStream->PeerPortConn.hInterHandle == SOUND_PORTID_PASSTHROUGH &&
@@ -3530,6 +3536,7 @@ HRESULT AMP_SND_SetStreamMute(AMP_IN HANDLE hStream, AMP_IN BOOL bMute)
         (pStream->PeerPortConn.hInterHandle == SOUND_PORTID_PASSTHROUGH &&
         pStream->PeerPortConn.uiFlags == HDMI_PATH))
     {
+        MV_OSAL_Mutex_Lock(pSndDrv->hDrvMutex);
 #ifdef CONFIG_AMP_AUDIO_MUTE_PT_FOR_STREAM
         SNDLOGD("HDMI pass through case, stream volume is set to AOUT!\n");
 #if 1 //tony debug
@@ -3545,6 +3552,7 @@ HRESULT AMP_SND_SetStreamMute(AMP_IN HANDLE hStream, AMP_IN BOOL bMute)
                      hStream);
         }
 #endif
+        MV_OSAL_Mutex_Unlock(pSndDrv->hDrvMutex);
         return rc;
     }