Index: head/emulators/virtualbox-ose/files/patch-src_VBox_Devices_Audio_DrvHostOSSAudio.cpp
===================================================================
--- head/emulators/virtualbox-ose/files/patch-src_VBox_Devices_Audio_DrvHostOSSAudio.cpp	(revision 568252)
+++ head/emulators/virtualbox-ose/files/patch-src_VBox_Devices_Audio_DrvHostOSSAudio.cpp	(revision 568253)
@@ -1,31 +1,31 @@
 --- src/VBox/Devices/Audio/DrvHostOSSAudio.cpp.orig	2021-01-07 15:37:12 UTC
 +++ src/VBox/Devices/Audio/DrvHostOSSAudio.cpp
 @@ -253,10 +253,11 @@ static int ossStreamOpen(const char *pszDev, int fOpen
  
              default:
                  rc = VERR_AUDIO_STREAM_COULD_NOT_CREATE;
-+                iFormat = -1;				
++                iFormat = -1;
                  break;
          }
  
 -        if (RT_FAILURE(rc))
 +        if (RT_UNLIKELY(iFormat == -1))
              break;
  
          if (ioctl(fdFile, SNDCTL_DSP_SAMPLESIZE, &iFormat))
 @@ -664,6 +665,7 @@ static int ossCreateStreamIn(POSSAUDIOSTREAM pStreamOS
  
                  pCfgAcq->Backend.cFramesPeriod     = PDMAUDIOSTREAMCFG_B2F(pCfgAcq, ossAcq.cbFragmentSize);
                  pCfgAcq->Backend.cFramesBufferSize = pCfgAcq->Backend.cFramesPeriod * 2; /* Use "double buffering". */
 +                pCfgAcq->Backend.cFramesPreBuffering     = pCfgAcq->Backend.cFramesBufferSize;                
                  /** @todo Pre-buffering required? */
              }
          }
 @@ -782,6 +784,7 @@ static int ossCreateStreamOut(POSSAUDIOSTREAM pStreamO
  #endif
              pCfgAcq->Backend.cFramesPeriod     = PDMAUDIOSTREAMCFG_B2F(pCfgAcq, obtStream.cbFragmentSize);
              pCfgAcq->Backend.cFramesBufferSize = pCfgAcq->Backend.cFramesPeriod * 2; /* Use "double buffering" */
 +            pCfgAcq->Backend.cFramesPreBuffering     = pCfgAcq->Backend.cFramesBufferSize;            
          }
  
      } while (0);