Changeset 70316 in vbox for trunk/src/VBox

Timestamp:

Dec 22, 2017 12:58:24 PM (7 years ago)

Author:

vboxsync

Message:

Audio/HDA: Take pending stream interrupts into account in hdaStreamTransferIsScheduled() and do the refcounting in hdaRegWriteSDSTS(). That way a re-scheduling in hdaTimerMain() should not happen anymore when an interrupt is pending and thus should improve timing accuracy quite a bit.

Location:

trunk/src/VBox/Devices/Audio

Files:

• DevHDA.cpp (modified) (2 diffs)
• HDAStream.cpp (modified) (3 diffs)

trunk/src/VBox/Devices/Audio/DevHDA.cpp

@@ -1478 +1478 @@
     }
 
+    hdaStreamLock(pStream);
+
     uint32_t v = HDA_REG_IND(pThis, iReg);
 
@@ -1557 +1559 @@
         /* Reset processed data counter. */
         pStream->State.cbTransferProcessed = 0;
+        pStream->State.tsTransferNext      = tsNow + cTicksToNext;
+
+        Assert(pStream->State.cTransferPendingInterrupts);
+        if (pStream->State.cTransferPendingInterrupts)
+            pStream->State.cTransferPendingInterrupts--;
 
         /* Re-arm the timer. */
         hdaTimerSet(pThis, tsNow + cTicksToNext, false /* fForce */);
     }
+
+    hdaStreamUnlock(pStream);
 
     DEVHDA_UNLOCK_BOTH(pThis);

trunk/src/VBox/Devices/Audio/HDAStream.cpp

@@ -560 +560 @@
 /**
  * Returns whether a next transfer for a given stream is scheduled or not.
+ * This takes pending stream interrupts into account as well as the next scheduled
+ * transfer timestamp.
  *
  * @returns True if a next transfer is scheduled, false if not.
@@ -572 +574 @@
 
     const bool fScheduled =    pStream->State.fRunning
-                            && pStream->State.tsTransferNext > TMTimerGet(pStream->pHDAState->pTimer);
-
-    Log3Func(("[SD%RU8] %RU64 -> %RTbool\n", pStream->u8SD, pStream->State.tsTransferNext, fScheduled));
+                            && (   pStream->State.cTransferPendingInterrupts
+                                || pStream->State.tsTransferNext > TMTimerGet(pStream->pHDAState->pTimer));
+
+    Log3Func(("[SD%RU8] tsTransferNext=%RU64, cTransferPendingInterrupts=%RU8 -> %RTbool\n",
+              pStream->u8SD, pStream->State.tsTransferNext, fScheduled));
 
     return fScheduled;
@@ -1098 +1102 @@
         hdaProcessInterrupt(pThis, __FUNCTION__);
 #endif
-        pStream->State.cTransferPendingInterrupts--;
     }
     else /* Transfer still in-flight -- schedule the next timing slot. */