Index: /trunk/src/VBox/Devices/Audio/DevIchAc97.cpp
===================================================================
--- /trunk/src/VBox/Devices/Audio/DevIchAc97.cpp	(revision 73647)
+++ /trunk/src/VBox/Devices/Audio/DevIchAc97.cpp	(revision 73648)
@@ -318,4 +318,10 @@
     AC97STREAMSTATEAIO    AIO;
 #endif
+    /** Timestamp (in ns) of last DMA transfer.
+     *  For output streams this is the last DMA read,
+     *  for input streams this is the last DMA write. */
+    uint64_t              tsLastTransferNs;
+    /** Timestamp (in ns) of last DMA buffer read / write. */
+    uint64_t              tsLastReadWriteNs;
 } AC97STREAMSTATE;
 AssertCompileSizeAlignment(AC97STREAMSTATE, 8);
@@ -1115,4 +1121,6 @@
     RTCircBufReleaseWriteBlock(pCircBuf, cbRead);
 
+    pDstStream->State.tsLastReadWriteNs = RTTimeNanoTS();
+
     if (pcbWritten)
         *pcbWritten = cbRead;
@@ -1182,4 +1190,6 @@
             break;
     }
+
+    pSrcStream->State.tsLastReadWriteNs = RTTimeNanoTS();
 
     if (pcbRead)
@@ -2683,4 +2693,6 @@
         }
     }
+
+    pStream->State.tsLastTransferNs = RTTimeNanoTS();
 
     ichac97R3StreamUnlock(pStream);