From 1ce3c74ebc3d39a222e406d0db79a1f3e56e7c43 Mon Sep 17 00:00:00 2001
From: Ross Owen <ross@xmos.com>
Date: Mon, 9 Dec 2013 15:49:50 +0000
Subject: [PATCH] Deliver to/from mixer comms fixed up for new underflow
 protocol

---
 module_usb_audio/audio.xc | 39 +++++++++++++++++++++++++++++++--------
 1 file changed, 31 insertions(+), 8 deletions(-)

diff --git a/module_usb_audio/audio.xc b/module_usb_audio/audio.xc
index c6a3821f..e1e9a94c 100755
--- a/module_usb_audio/audio.xc
+++ b/module_usb_audio/audio.xc
@@ -209,8 +209,8 @@ static inline void doI2SClocks(unsigned divide)
     }
     else
     {
-#ifndef MIXER // Interfaces straight to decouple()
         underflow = inuint(c_out);
+#ifndef MIXER // Interfaces straight to decouple()
 
 #if NUM_USB_CHAN_IN > 0
 #pragma loop unroll
@@ -238,7 +238,18 @@ static inline void doI2SClocks(unsigned divide)
             }
         }
 #endif
-#else
+#else /* ifndef MIXER */
+
+        if(underflow)
+        {
+            #pragma loop unroll
+            for(int i = 0; i < NUM_USB_CHAN_OUT; i++)        
+            {
+                samplesOut[i] = underflowWord;
+            }
+        }
+        else
+        {        
 #pragma loop unroll
         for(int i = 0; i < NUM_USB_CHAN_OUT; i++)        
         {
@@ -248,6 +259,7 @@ static inline void doI2SClocks(unsigned divide)
 #endif
             samplesOut[i] = tmp;
         }
+        }
         	 
 #pragma loop unroll
         for(int i = 0; i < NUM_USB_CHAN_IN; i++)
@@ -387,8 +399,8 @@ static inline void doI2SClocks(unsigned divide)
         }
         else
         {
-#ifndef MIXER // Interfaces straight to decouple()
             underflow = inuint(c_out);
+#ifndef MIXER // Interfaces straight to decouple()
 #if NUM_USB_CHAN_IN > 0
 #pragma loop unroll
             for(int i = 0; i < NUM_USB_CHAN_IN; i++)
@@ -416,14 +428,25 @@ static inline void doI2SClocks(unsigned divide)
             }
 #endif
 #else /* ifndef MIXER */
-#pragma loop unroll
-            for(int i = 0; i < NUM_USB_CHAN_OUT; i++)
+
+            if(underflow)
+            { 
+                for(int i = 0; i < NUM_USB_CHAN_OUT; i++)
+                {
+                    samplesOut[i] = underflowWord;
+                }
+            }
+            else
             {
-                int tmp = inuint(c_out);
+#pragma loop unroll
+                for(int i = 0; i < NUM_USB_CHAN_OUT; i++)
+                {   
+                    int tmp = inuint(c_out);
 #if defined(OUT_VOLUME_IN_MIXER) && defined(OUT_VOLUME_AFTER_MIX)
-                tmp<<=3;
+                    tmp<<=3;
 #endif
-                samplesOut[i] = tmp;
+                    samplesOut[i] = tmp;
+                }
             }
 
 #pragma loop unroll