audioflinger: fix duplicating thread output buffers clear

Also clear mix buffer in DuplicatingThread::threadLoop_mix()
instead of just sink buffer when output threads are not
ready.

Bug: 18262127.
Change-Id: I4c22bbeaccdcc8d7c10c5882dde3439eb73d6ede
(cherry picked from commit 02b5708776ba2a9b4ff8c09008483aef7dbe38c7)

1 files changed, 5 insertions, 1 deletions

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index e443476..71a6a73 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -4660,7 +4660,11 @@ void AudioFlinger::DuplicatingThread::threadLoop_mix()
     if (outputsReady(outputTracks)) {
         mAudioMixer->process(AudioBufferProvider::kInvalidPTS);
     } else {
-        memset(mSinkBuffer, 0, mSinkBufferSize);
+        if (mMixerBufferValid) {
+            memset(mMixerBuffer, 0, mMixerBufferSize);
+        } else {
+            memset(mSinkBuffer, 0, mSinkBufferSize);
+        }
     }
     sleepTime = 0;
     writeFrames = mNormalFrameCount;