AudioFlinger: Fix re-use of fast-track

When a fast-track using shared buffer is restarted, we need to call
obtainbuffer if frameReady has already become zero, even if track is
still active. This is required to reset mFramesReadySafe. Otherwise
mFramesReadySafe remain at 0 and fastmixer can't consume data from
the track when it is re-used.

Change-Id: I5d6f364f8f31baad3341bd4f51bf8a8b147cd7d7

1 files changed, 8 insertions, 4 deletions

diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 98eb87f..4eb13dc 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -707,10 +707,11 @@ status_t AudioFlinger::PlaybackThread::Track::start(AudioSystem::sync_event_t ev
                 mState = state;
             }
         }
-        // track was already in the active list, not a problem
-        if (status == ALREADY_EXISTS) {
-            status = NO_ERROR;
-        } else {
+        // If track was already in the active list, not a problem unless
+        // track is fast and sharedBuffer is used and frameReady has already become 0.
+        // In such case we need to call obtainbuffer() to refresh the framesReady value.
+        if ((status != ALREADY_EXISTS) ||
+            (isFastTrack() && (mSharedBuffer != 0) && (framesReady() == 0))) {
             // Acknowledge any pending flush(), so that subsequent new data isn't discarded.
             // It is usually unsafe to access the server proxy from a binder thread.
             // But in this case we know the mixer thread (whether normal mixer or fast mixer)
@@ -720,6 +721,9 @@ status_t AudioFlinger::PlaybackThread::Track::start(AudioSystem::sync_event_t ev
             buffer.mFrameCount = 1;
             (void) mAudioTrackServerProxy->obtainBuffer(&buffer, true /*ackFlush*/);
         }
+
+        if (status == ALREADY_EXISTS)
+            status = NO_ERROR;
     } else {
         status = BAD_VALUE;
     }