diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index dfae5d9..8297b5c 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -71,6 +71,7 @@
 #endif
             const sp<IMemory>& sharedBuffer,
             int sessionId,
+            int clientUid,
             bool isOut)
     :   RefBase(),
         mThread(thread),
@@ -99,6 +100,18 @@
         mId(android_atomic_inc(&nextTrackId)),
         mTerminated(false)
 {
+    // if the caller is us, trust the specified uid
+    if (IPCThreadState::self()->getCallingPid() != getpid_cached || clientUid == -1) {
+        int newclientUid = IPCThreadState::self()->getCallingUid();
+        if (clientUid != -1 && clientUid != newclientUid) {
+            ALOGW("uid %d tried to pass itself off as %d", newclientUid, clientUid);
+        }
+        clientUid = newclientUid;
+    }
+    // clientUid contains the uid of the app that is responsible for this track, so we can blame
+    // battery usage on it.
+    mUid = clientUid;
+
     // client == 0 implies sharedBuffer == 0
     ALOG_ASSERT(!(client == 0 && sharedBuffer != 0));
 
@@ -374,14 +387,15 @@
             size_t frameCount,
             const sp<IMemory>& sharedBuffer,
             int sessionId,
+            int uid,
             IAudioFlinger::track_flags_t flags)
 #ifdef QCOM_HARDWARE
     :   TrackBase(thread, client, sampleRate, format, channelMask, frameCount,
      ((audio_stream_type_t)streamType == AUDIO_STREAM_VOICE_CALL)? IAudioFlinger::TRACK_VOICE_COMMUNICATION:0x0,
-     sharedBuffer, sessionId, true /*isOut*/),
+     sharedBuffer, sessionId, uid, true /*isOut*/),
 #else
     :   TrackBase(thread, client, sampleRate, format, channelMask, frameCount, sharedBuffer,
-            sessionId, true /*isOut*/),
+            sessionId, uid, true /*isOut*/),
 #endif
     mFillingUpStatus(FS_INVALID),
     // mRetryCount initialized later when needed
@@ -905,6 +919,7 @@
                                         dstChain->strategy(),
                                         AUDIO_SESSION_OUTPUT_MIX,
                                         effect->id());
+            AudioSystem::setEffectEnabled(effect->id(), effect->isEnabled());
         }
         status = playbackThread->attachAuxEffect(this, EffectId);
     }
@@ -1030,13 +1045,14 @@
             audio_channel_mask_t channelMask,
             size_t frameCount,
             const sp<IMemory>& sharedBuffer,
-            int sessionId) {
+            int sessionId,
+            int uid) {
     if (!client->reserveTimedTrack())
         return 0;
 
     return new TimedTrack(
         thread, client, streamType, sampleRate, format, channelMask, frameCount,
-        sharedBuffer, sessionId);
+        sharedBuffer, sessionId, uid);
 }
 
 AudioFlinger::PlaybackThread::TimedTrack::TimedTrack(
@@ -1048,9 +1064,10 @@
             audio_channel_mask_t channelMask,
             size_t frameCount,
             const sp<IMemory>& sharedBuffer,
-            int sessionId)
+            int sessionId,
+            int uid)
     : Track(thread, client, streamType, sampleRate, format, channelMask,
-            frameCount, sharedBuffer, sessionId, IAudioFlinger::TRACK_TIMED),
+            frameCount, sharedBuffer, sessionId, uid, IAudioFlinger::TRACK_TIMED),
       mQueueHeadInFlight(false),
       mTrimQueueHeadOnRelease(false),
       mFramesPendingInQueue(0),
@@ -1543,9 +1560,10 @@
             uint32_t sampleRate,
             audio_format_t format,
             audio_channel_mask_t channelMask,
-            size_t frameCount)
+            size_t frameCount,
+            int uid)
     :   Track(playbackThread, NULL, AUDIO_STREAM_CNT, sampleRate, format, channelMask, frameCount,
-                NULL, 0, IAudioFlinger::TRACK_DEFAULT),
+                NULL, 0, uid, IAudioFlinger::TRACK_DEFAULT),
     mActive(false), mSourceThread(sourceThread), mClientProxy(NULL)
 {
 
@@ -1808,13 +1826,14 @@
 #ifdef QCOM_HARDWARE
             uint32_t flags,
 #endif
-            int sessionId)
+            int sessionId,
+            int uid)
 #ifdef QCOM_HARDWARE
     :   TrackBase(thread, client, sampleRate, format, channelMask, frameCount,
-        flags, 0 /*sharedBuffer*/, sessionId, false /*isOut*/),
+        flags, 0 /*sharedBuffer*/, sessionId, uid, false /*isOut*/),
 #else
     :   TrackBase(thread, client, sampleRate, format,
-                  channelMask, frameCount, 0 /*sharedBuffer*/, sessionId, false /*isOut*/),
+                  channelMask, frameCount, 0 /*sharedBuffer*/, sessionId, uid, false /*isOut*/),
 #endif
         mOverflow(false)
 {