diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 8ce819c..7a2a773 100755
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -2862,8 +2862,6 @@
         }
 #endif
 
-    } else {
-        mFastMixer = NULL;
     }
 
     switch (kUseFastMixer) {
@@ -2882,7 +2880,7 @@
 
 AudioFlinger::MixerThread::~MixerThread()
 {
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         FastMixerStateQueue *sq = mFastMixer->sq();
         FastMixerState *state = sq->begin();
         if (state->mCommand == FastMixerState::COLD_IDLE) {
@@ -2904,7 +2902,7 @@
         ALOG_ASSERT(fastTrack->mBufferProvider != NULL);
         delete fastTrack->mBufferProvider;
         sq->end(false /*didModify*/);
-        delete mFastMixer;
+        mFastMixer.clear();
 #ifdef AUDIO_WATCHDOG
         if (mAudioWatchdog != 0) {
             mAudioWatchdog->requestExit();
@@ -2920,7 +2918,7 @@
 
 uint32_t AudioFlinger::MixerThread::correctLatency_l(uint32_t latency) const
 {
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         MonoPipe *pipe = (MonoPipe *)mPipeSink.get();
         latency += (pipe->getAvgFrames() * 1000) / mSampleRate;
     }
@@ -2937,7 +2935,7 @@
 {
     // FIXME we should only do one push per cycle; confirm this is true
     // Start the fast mixer if it's not already running
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         FastMixerStateQueue *sq = mFastMixer->sq();
         FastMixerState *state = sq->begin();
         if (state->mCommand != FastMixerState::MIX_WRITE &&
@@ -2971,7 +2969,7 @@
 void AudioFlinger::MixerThread::threadLoop_standby()
 {
     // Idle the fast mixer if it's currently running
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         FastMixerStateQueue *sq = mFastMixer->sq();
         FastMixerState *state = sq->begin();
         if (!(state->mCommand & FastMixerState::IDLE)) {
@@ -3134,7 +3132,7 @@
     FastMixerState *state = NULL;
     bool didModify = false;
     FastMixerStateQueue::block_t block = FastMixerStateQueue::BLOCK_UNTIL_PUSHED;
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         sq = mFastMixer->sq();
         state = sq->begin();
     }
@@ -3677,7 +3675,7 @@
 
     // if !&IDLE, holds the FastMixer state to restore after new parameters processed
     FastMixerState::Command previousCommand = FastMixerState::HOT_IDLE;
-    if (mFastMixer != NULL) {
+    if (mFastMixer != 0) {
         FastMixerStateQueue *sq = mFastMixer->sq();
         FastMixerState *state = sq->begin();
         if (!(state->mCommand & FastMixerState::IDLE)) {
@@ -3782,7 +3780,7 @@
     }
 
     if (!(previousCommand & FastMixerState::IDLE)) {
-        ALOG_ASSERT(mFastMixer != NULL);
+        ALOG_ASSERT(mFastMixer != 0);
         FastMixerStateQueue *sq = mFastMixer->sq();
         FastMixerState *state = sq->begin();
         ALOG_ASSERT(state->mCommand == FastMixerState::HOT_IDLE);
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 07887fb..93d2635 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -852,7 +852,7 @@
                 AudioMixer* mAudioMixer;    // normal mixer
 private:
                 // one-time initialization, no locks required
-                FastMixer*  mFastMixer;         // non-NULL if there is also a fast mixer
+                sp<FastMixer>     mFastMixer;     // non-0 if there is also a fast mixer
                 sp<AudioWatchdog> mAudioWatchdog; // non-0 if there is an audio watchdog thread
 
                 // contents are not guaranteed to be consistent, no locks required
@@ -868,7 +868,7 @@
                 int32_t     mFastMixerFutex;    // for cold idle
 
 public:
-    virtual     bool        hasFastMixer() const { return mFastMixer != NULL; }
+    virtual     bool        hasFastMixer() const { return mFastMixer != 0; }
     virtual     FastTrackUnderruns getFastTrackUnderruns(size_t fastIndex) const {
                               ALOG_ASSERT(fastIndex < FastMixerState::kMaxFastTracks);
                               return mFastMixerDumpState.mTracks[fastIndex].mUnderruns;