diff --git a/include/media/AudioIoDescriptor.h b/include/media/AudioIoDescriptor.h
index 2437901..c94b738 100644
--- a/include/media/AudioIoDescriptor.h
+++ b/include/media/AudioIoDescriptor.h
@@ -33,12 +33,31 @@
 class AudioIoDescriptor : public RefBase {
 public:
     AudioIoDescriptor() :
+        mIoHandle(AUDIO_IO_HANDLE_NONE),
         mSamplingRate(0), mFormat(AUDIO_FORMAT_DEFAULT), mChannelMask(AUDIO_CHANNEL_NONE),
-        mFrameCount(0), mLatency(0) {}
+        mFrameCount(0), mLatency(0)
+    {
+        memset(&mPatch, 0, sizeof(struct audio_patch));
+    }
 
     virtual ~AudioIoDescriptor() {}
 
+    audio_port_handle_t getDeviceId() {
+        if (mPatch.num_sources != 0 && mPatch.num_sinks != 0) {
+            if (mPatch.sources[0].type == AUDIO_PORT_TYPE_MIX) {
+                // this is an output mix
+                // FIXME: the API only returns the first device in case of multiple device selection
+                return mPatch.sinks[0].id;
+            } else {
+                // this is an input mix
+                return mPatch.sources[0].id;
+            }
+        }
+        return AUDIO_PORT_HANDLE_NONE;
+    }
+
     audio_io_handle_t mIoHandle;
+    struct audio_patch mPatch;
     uint32_t mSamplingRate;
     audio_format_t mFormat;
     audio_channel_mask_t mChannelMask;
diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index b743c11..0403e1a 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -390,6 +390,39 @@
      * TODO Document this method.
      */
             audio_port_handle_t getInputDevice();
+
+     /* Returns the ID of the audio device actually used by the input to which this AudioRecord
+      * is attached.
+      * A value of AUDIO_PORT_HANDLE_NONE indicates the AudioRecord is not attached to any input.
+      *
+      * Parameters:
+      *  none.
+      */
+     audio_port_handle_t getRoutedDeviceId();
+
+    /* Add an AudioDeviceCallback. The caller will be notified when the audio device
+     * to which this AudioRecord is routed is updated.
+     * Replaces any previously installed callback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the same callback is already installed.
+     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t addAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
+    /* remove an AudioDeviceCallback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the callback is not installed
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t removeAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
 private:
     /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
      * additional non-contiguous frames that are predicted to be available immediately,
@@ -582,6 +615,7 @@
     // For Device Selection API
     //  a value of AUDIO_PORT_HANDLE_NONE indicated default (AudioPolicyManager) routing.
     audio_port_handle_t    mSelectedDeviceId;
+    sp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
 };
 
 }; // namespace android
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 0cbcdb1..3241e9c 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -332,8 +332,26 @@
 
     };
 
-    static status_t addAudioPortCallback(const sp<AudioPortCallback>& callBack);
-    static status_t removeAudioPortCallback(const sp<AudioPortCallback>& callBack);
+    static status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
+    static status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
+
+    class AudioDeviceCallback : public RefBase
+    {
+    public:
+
+                AudioDeviceCallback() {}
+        virtual ~AudioDeviceCallback() {}
+
+        virtual void onAudioDeviceUpdate(audio_io_handle_t audioIo,
+                                         audio_port_handle_t deviceId) = 0;
+    };
+
+    static status_t addAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                           audio_io_handle_t audioIo);
+    static status_t removeAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                              audio_io_handle_t audioIo);
+
+    static audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
 
 private:
 
@@ -359,10 +377,20 @@
         // values for output/input parameters up-to-date in client process
         virtual void ioConfigChanged(audio_io_config_event event,
                                      const sp<AudioIoDescriptor>& ioDesc);
+
+
+        status_t addAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                               audio_io_handle_t audioIo);
+        status_t removeAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                           audio_io_handle_t audioIo);
+
+        audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
+
     private:
         Mutex                               mLock;
-        DefaultKeyedVector<audio_io_handle_t, sp<AudioIoDescriptor> > mIoDescriptors;
-
+        DefaultKeyedVector<audio_io_handle_t, sp<AudioIoDescriptor> >   mIoDescriptors;
+        DefaultKeyedVector<audio_io_handle_t, Vector < sp<AudioDeviceCallback> > >
+                                                                        mAudioDeviceCallbacks;
         // cached values for recording getInputBufferSize() queries
         size_t                              mInBuffSize;    // zero indicates cache is invalid
         uint32_t                            mInSamplingRate;
@@ -377,8 +405,8 @@
         AudioPolicyServiceClient() {
         }
 
-        status_t addAudioPortCallback(const sp<AudioPortCallback>& callBack);
-        status_t removeAudioPortCallback(const sp<AudioPortCallback>& callBack);
+        status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
+        status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
 
         // DeathRecipient
         virtual void binderDied(const wp<IBinder>& who);
@@ -393,6 +421,9 @@
         Vector <sp <AudioPortCallback> >    mAudioPortCallbacks;
     };
 
+    static const sp<AudioFlingerClient> getAudioFlingerClient();
+    static sp<AudioIoDescriptor> getIoDescriptor(audio_io_handle_t ioHandle);
+
     static sp<AudioFlingerClient> gAudioFlingerClient;
     static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
     friend class AudioFlingerClient;
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index 0ccd19e..458f4b4 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -510,7 +510,7 @@
      */
             status_t    setOutputDevice(audio_port_handle_t deviceId);
 
-    /* Returns the ID of the audio device used for output of this AudioTrack.
+    /* Returns the ID of the audio device selected for this AudioTrack.
      * A value of AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
      *
      * Parameters:
@@ -518,6 +518,15 @@
      */
      audio_port_handle_t getOutputDevice();
 
+     /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
+      * attached.
+      * A value of AUDIO_PORT_HANDLE_NONE indicates the audio track is not attached to any output.
+      *
+      * Parameters:
+      *  none.
+      */
+     audio_port_handle_t getRoutedDeviceId();
+
     /* Returns the unique session ID associated with this track.
      *
      * Parameters:
@@ -664,6 +673,28 @@
      */
             status_t    getTimestamp(AudioTimestamp& timestamp);
 
+    /* Add an AudioDeviceCallback. The caller will be notified when the audio device to which this
+     * AudioTrack is routed is updated.
+     * Replaces any previously installed callback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the same callback is already installed.
+     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
+
+    /* remove an AudioDeviceCallback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the callback is not installed
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t removeAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
 protected:
     /* copying audio tracks is not allowed */
                         AudioTrack(const AudioTrack& other);
@@ -885,6 +916,8 @@
     uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
     int                     mClientUid;
     pid_t                   mClientPid;
+
+    sp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
 };
 
 class TimedAudioTrack : public AudioTrack
diff --git a/media/libmedia/AudioRecord.cpp b/media/libmedia/AudioRecord.cpp
index 23015c0..73fd3cb 100644
--- a/media/libmedia/AudioRecord.cpp
+++ b/media/libmedia/AudioRecord.cpp
@@ -112,6 +112,10 @@
             mAudioRecordThread->requestExitAndWait();
             mAudioRecordThread.clear();
         }
+        // No lock here: worst case we remove a NULL callback which will be a nop
+        if (mDeviceCallback != 0 && mInput != AUDIO_IO_HANDLE_NONE) {
+            AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mInput);
+        }
         IInterface::asBinder(mAudioRecord)->unlinkToDeath(mDeathNotifier, this);
         mAudioRecord.clear();
         mCblkMemory.clear();
@@ -286,6 +290,8 @@
     mNewPosition = mProxy->getPosition() + mUpdatePeriod;
     int32_t flags = android_atomic_acquire_load(&mCblk->mFlags);
 
+    mActive = true;
+
     status_t status = NO_ERROR;
     if (!(flags & CBLK_INVALID)) {
         status = mAudioRecord->start(event, triggerSession);
@@ -298,9 +304,9 @@
     }
 
     if (status != NO_ERROR) {
+        mActive = false;
         ALOGE("start() status %d", status);
     } else {
-        mActive = true;
         sp<AudioRecordThread> t = mAudioRecordThread;
         if (t != 0) {
             t->resume();
@@ -425,6 +431,11 @@
     AutoMutex lock(mLock);
     if (mSelectedDeviceId != deviceId) {
         mSelectedDeviceId = deviceId;
+        // stop capture so that audio policy manager does not reject the new instance start request
+        // as only one capture can be active at a time.
+        if (mAudioRecord != 0 && mActive) {
+            mAudioRecord->stop();
+        }
         android_atomic_or(CBLK_INVALID, &mCblk->mFlags);
     }
     return NO_ERROR;
@@ -435,6 +446,14 @@
     return mSelectedDeviceId;
 }
 
+audio_port_handle_t AudioRecord::getRoutedDeviceId() {
+    AutoMutex lock(mLock);
+    if (mInput == AUDIO_IO_HANDLE_NONE) {
+        return AUDIO_PORT_HANDLE_NONE;
+    }
+    return AudioSystem::getDeviceIdForIo(mInput);
+}
+
 // -------------------------------------------------------------------------
 
 // must be called with mLock held
@@ -478,6 +497,10 @@
         }
     }
 
+    if (mDeviceCallback != 0 && mInput != AUDIO_IO_HANDLE_NONE) {
+        AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mInput);
+    }
+
     audio_io_handle_t input;
     status_t status = AudioSystem::getInputForAttr(&mAttributes, &input,
                                         (audio_session_t)mSessionId,
@@ -609,6 +632,10 @@
     mDeathNotifier = new DeathNotifier(this);
     IInterface::asBinder(mAudioRecord)->linkToDeath(mDeathNotifier, this);
 
+    if (mDeviceCallback != 0) {
+        AudioSystem::addAudioDeviceCallback(mDeviceCallback, mInput);
+    }
+
     return NO_ERROR;
     }
 
@@ -1054,6 +1081,48 @@
     return result;
 }
 
+status_t AudioRecord::addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback)
+{
+    if (callback == 0) {
+        ALOGW("%s adding NULL callback!", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    AutoMutex lock(mLock);
+    if (mDeviceCallback == callback) {
+        ALOGW("%s adding same callback!", __FUNCTION__);
+        return INVALID_OPERATION;
+    }
+    status_t status = NO_ERROR;
+    if (mInput != AUDIO_IO_HANDLE_NONE) {
+        if (mDeviceCallback != 0) {
+            ALOGW("%s callback already present!", __FUNCTION__);
+            AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mInput);
+        }
+        status = AudioSystem::addAudioDeviceCallback(callback, mInput);
+    }
+    mDeviceCallback = callback;
+    return status;
+}
+
+status_t AudioRecord::removeAudioDeviceCallback(
+        const sp<AudioSystem::AudioDeviceCallback>& callback)
+{
+    if (callback == 0) {
+        ALOGW("%s removing NULL callback!", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    AutoMutex lock(mLock);
+    if (mDeviceCallback != callback) {
+        ALOGW("%s removing different callback!", __FUNCTION__);
+        return INVALID_OPERATION;
+    }
+    if (mInput != AUDIO_IO_HANDLE_NONE) {
+        AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mInput);
+    }
+    mDeviceCallback = 0;
+    return NO_ERROR;
+}
+
 // =========================================================================
 
 void AudioRecord::DeathNotifier::binderDied(const wp<IBinder>& who __unused)
diff --git a/media/libmedia/AudioSystem.cpp b/media/libmedia/AudioSystem.cpp
index 85ed2b1..4c2e77b 100644
--- a/media/libmedia/AudioSystem.cpp
+++ b/media/libmedia/AudioSystem.cpp
@@ -76,6 +76,25 @@
     return af;
 }
 
+const sp<AudioSystem::AudioFlingerClient> AudioSystem::getAudioFlingerClient()
+{
+    // calling get_audio_flinger() will initialize gAudioFlingerClient if needed
+    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
+    if (af == 0) return 0;
+    Mutex::Autolock _l(gLock);
+    return gAudioFlingerClient;
+}
+
+sp<AudioIoDescriptor> AudioSystem::getIoDescriptor(audio_io_handle_t ioHandle)
+{
+    sp<AudioIoDescriptor> desc;
+    const sp<AudioFlingerClient> afc = getAudioFlingerClient();
+    if (afc != 0) {
+        desc = afc->getIoDescriptor(ioHandle);
+    }
+    return desc;
+}
+
 /* static */ status_t AudioSystem::checkAudioFlinger()
 {
     if (defaultServiceManager()->checkService(String16("media.audio_flinger")) != 0) {
@@ -249,9 +268,7 @@
 {
     const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
     if (af == 0) return PERMISSION_DENIED;
-
-    LOG_ALWAYS_FATAL_IF(gAudioFlingerClient == 0);
-    sp<AudioIoDescriptor> outputDesc = gAudioFlingerClient->getIoDescriptor(output);
+    sp<AudioIoDescriptor> outputDesc = getIoDescriptor(output);
     if (outputDesc == 0) {
         ALOGV("getOutputSamplingRate() no output descriptor for output %d in gOutputs", output);
         *samplingRate = af->sampleRate(output);
@@ -290,9 +307,7 @@
 {
     const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
     if (af == 0) return PERMISSION_DENIED;
-
-    LOG_ALWAYS_FATAL_IF(gAudioFlingerClient == 0);
-    sp<AudioIoDescriptor> outputDesc = gAudioFlingerClient->getIoDescriptor(output);
+    sp<AudioIoDescriptor> outputDesc = getIoDescriptor(output);
     if (outputDesc == 0) {
         *frameCount = af->frameCount(output);
     } else {
@@ -329,9 +344,7 @@
 {
     const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
     if (af == 0) return PERMISSION_DENIED;
-
-    LOG_ALWAYS_FATAL_IF(gAudioFlingerClient == 0);
-    sp<AudioIoDescriptor> outputDesc = gAudioFlingerClient->getIoDescriptor(output);
+    sp<AudioIoDescriptor> outputDesc = getIoDescriptor(output);
     if (outputDesc == 0) {
         *latency = af->latency(output);
     } else {
@@ -346,10 +359,11 @@
 status_t AudioSystem::getInputBufferSize(uint32_t sampleRate, audio_format_t format,
         audio_channel_mask_t channelMask, size_t* buffSize)
 {
-    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
-    if (af == 0) return PERMISSION_DENIED;
-    LOG_ALWAYS_FATAL_IF(gAudioFlingerClient == 0);
-    return gAudioFlingerClient->getInputBufferSize(sampleRate, format, channelMask, buffSize);
+    const sp<AudioFlingerClient> afc = getAudioFlingerClient();
+    if (afc == 0) {
+        return NO_INIT;
+    }
+    return afc->getInputBufferSize(sampleRate, format, channelMask, buffSize);
 }
 
 status_t AudioSystem::setVoiceVolume(float value)
@@ -446,47 +460,77 @@
 
     if (ioDesc == 0 || ioDesc->mIoHandle == AUDIO_IO_HANDLE_NONE) return;
 
-    Mutex::Autolock _l(mLock);
+    audio_port_handle_t deviceId = AUDIO_PORT_HANDLE_NONE;
+    Vector < sp<AudioDeviceCallback> > callbacks;
 
-    switch (event) {
-    case AUDIO_OUTPUT_OPENED:
-    case AUDIO_INPUT_OPENED: {
-        if (getIoDescriptor(ioDesc->mIoHandle) != 0) {
-            ALOGV("ioConfigChanged() opening already existing output! %d", ioDesc->mIoHandle);
-            break;
-        }
-        mIoDescriptors.add(ioDesc->mIoHandle, ioDesc);
-        ALOGV("ioConfigChanged() new %s opened %d samplingRate %u, format %#x channel mask %#x "
-                "frameCount %zu", event == AUDIO_OUTPUT_OPENED ? "output" : "input",
-                ioDesc->mIoHandle, ioDesc->mSamplingRate, ioDesc->mFormat, ioDesc->mChannelMask,
-                ioDesc->mFrameCount);
-        } break;
-    case AUDIO_OUTPUT_CLOSED:
-    case AUDIO_INPUT_CLOSED: {
-        if (getIoDescriptor(ioDesc->mIoHandle) == 0) {
-            ALOGW("ioConfigChanged() closing unknown %s %d",
+    {
+        Mutex::Autolock _l(mLock);
+
+        switch (event) {
+        case AUDIO_OUTPUT_OPENED:
+        case AUDIO_INPUT_OPENED: {
+            if (getIoDescriptor(ioDesc->mIoHandle) != 0) {
+                ALOGV("ioConfigChanged() opening already existing output! %d", ioDesc->mIoHandle);
+                break;
+            }
+            mIoDescriptors.add(ioDesc->mIoHandle, ioDesc);
+
+            if (ioDesc->getDeviceId() != AUDIO_PORT_HANDLE_NONE) {
+                deviceId = ioDesc->getDeviceId();
+                ssize_t ioIndex = mAudioDeviceCallbacks.indexOfKey(ioDesc->mIoHandle);
+                if (ioIndex >= 0) {
+                    callbacks = mAudioDeviceCallbacks.valueAt(ioIndex);
+                }
+            }
+            ALOGV("ioConfigChanged() new %s opened %d samplingRate %u, format %#x channel mask %#x "
+                    "frameCount %zu deviceId %d", event == AUDIO_OUTPUT_OPENED ? "output" : "input",
+                    ioDesc->mIoHandle, ioDesc->mSamplingRate, ioDesc->mFormat, ioDesc->mChannelMask,
+                    ioDesc->mFrameCount, ioDesc->getDeviceId());
+            } break;
+        case AUDIO_OUTPUT_CLOSED:
+        case AUDIO_INPUT_CLOSED: {
+            if (getIoDescriptor(ioDesc->mIoHandle) == 0) {
+                ALOGW("ioConfigChanged() closing unknown %s %d",
+                      event == AUDIO_OUTPUT_CLOSED ? "output" : "input", ioDesc->mIoHandle);
+                break;
+            }
+            ALOGV("ioConfigChanged() %s %d closed",
                   event == AUDIO_OUTPUT_CLOSED ? "output" : "input", ioDesc->mIoHandle);
-            break;
-        }
-        ALOGV("ioConfigChanged() %s %d closed", event == AUDIO_OUTPUT_CLOSED ? "output" : "input",
-                ioDesc->mIoHandle);
 
-        mIoDescriptors.removeItem(ioDesc->mIoHandle);
+            mIoDescriptors.removeItem(ioDesc->mIoHandle);
+            mAudioDeviceCallbacks.removeItem(ioDesc->mIoHandle);
+            } break;
+
+        case AUDIO_OUTPUT_CONFIG_CHANGED:
+        case AUDIO_INPUT_CONFIG_CHANGED: {
+            sp<AudioIoDescriptor> oldDesc = getIoDescriptor(ioDesc->mIoHandle);
+            if (oldDesc == 0) {
+                ALOGW("ioConfigChanged() modifying unknown output! %d", ioDesc->mIoHandle);
+                break;
+            }
+
+            deviceId = oldDesc->getDeviceId();
+            mIoDescriptors.replaceValueFor(ioDesc->mIoHandle, ioDesc);
+
+            if (deviceId != ioDesc->getDeviceId()) {
+                deviceId = ioDesc->getDeviceId();
+                ssize_t ioIndex = mAudioDeviceCallbacks.indexOfKey(ioDesc->mIoHandle);
+                if (ioIndex >= 0) {
+                    callbacks = mAudioDeviceCallbacks.valueAt(ioIndex);
+                }
+            }
+            ALOGV("ioConfigChanged() new config for %s %d samplingRate %u, format %#x "
+                    "channel mask %#x frameCount %zu deviceId %d",
+                    event == AUDIO_OUTPUT_CONFIG_CHANGED ? "output" : "input",
+                    ioDesc->mIoHandle, ioDesc->mSamplingRate, ioDesc->mFormat,
+                    ioDesc->mChannelMask, ioDesc->mFrameCount, ioDesc->getDeviceId());
+
         } break;
-
-    case AUDIO_OUTPUT_CONFIG_CHANGED:
-    case AUDIO_INPUT_CONFIG_CHANGED: {
-        if (getIoDescriptor(ioDesc->mIoHandle) == 0) {
-            ALOGW("ioConfigChanged() modifying unknown output! %d", ioDesc->mIoHandle);
-            break;
         }
-        mIoDescriptors.replaceValueFor(ioDesc->mIoHandle, ioDesc);
-        ALOGV("ioConfigChanged() new config for %s %d samplingRate %u, format %#x "
-                "channel mask %#x frameCount %zu",
-                event == AUDIO_OUTPUT_CONFIG_CHANGED ? "output" : "input",
-                ioDesc->mIoHandle, ioDesc->mSamplingRate, ioDesc->mFormat,
-                ioDesc->mChannelMask, ioDesc->mFrameCount);
-    } break;
+    }
+    // callbacks.size() != 0 =>  ioDesc->mIoHandle and deviceId are valid
+    for (size_t i = 0; i < callbacks.size(); i++) {
+        callbacks[i]->onAudioDeviceUpdate(ioDesc->mIoHandle, deviceId);
     }
 }
 
@@ -532,7 +576,56 @@
     return desc;
 }
 
-/*static*/ void AudioSystem::setErrorCallback(audio_error_callback cb)
+status_t AudioSystem::AudioFlingerClient::addAudioDeviceCallback(
+        const sp<AudioDeviceCallback>& callback, audio_io_handle_t audioIo)
+{
+    Mutex::Autolock _l(mLock);
+    Vector < sp<AudioDeviceCallback> > callbacks;
+    ssize_t ioIndex = mAudioDeviceCallbacks.indexOfKey(audioIo);
+    if (ioIndex >= 0) {
+        callbacks = mAudioDeviceCallbacks.valueAt(ioIndex);
+    }
+
+    for (size_t cbIndex = 0; cbIndex < callbacks.size(); cbIndex++) {
+        if (callbacks[cbIndex] == callback) {
+            return INVALID_OPERATION;
+        }
+    }
+    callbacks.add(callback);
+
+    mAudioDeviceCallbacks.replaceValueFor(audioIo, callbacks);
+    return NO_ERROR;
+}
+
+status_t AudioSystem::AudioFlingerClient::removeAudioDeviceCallback(
+        const sp<AudioDeviceCallback>& callback, audio_io_handle_t audioIo)
+{
+    Mutex::Autolock _l(mLock);
+    ssize_t ioIndex = mAudioDeviceCallbacks.indexOfKey(audioIo);
+    if (ioIndex < 0) {
+        return INVALID_OPERATION;
+    }
+    Vector < sp<AudioDeviceCallback> > callbacks = mAudioDeviceCallbacks.valueAt(ioIndex);
+
+    size_t cbIndex;
+    for (cbIndex = 0; cbIndex < callbacks.size(); cbIndex++) {
+        if (callbacks[cbIndex] == callback) {
+            break;
+        }
+    }
+    if (cbIndex == callbacks.size()) {
+        return INVALID_OPERATION;
+    }
+    callbacks.removeAt(cbIndex);
+    if (callbacks.size() != 0) {
+        mAudioDeviceCallbacks.replaceValueFor(audioIo, callbacks);
+    } else {
+        mAudioDeviceCallbacks.removeItem(audioIo);
+    }
+    return NO_ERROR;
+}
+
+/* static */ void AudioSystem::setErrorCallback(audio_error_callback cb)
 {
     Mutex::Autolock _l(gLock);
     gAudioErrorCallback = cb;
@@ -864,11 +957,11 @@
 {
     // called by restoreTrack_l(), which needs new IAudioFlinger and IAudioPolicyService instances
     ALOGV("clearAudioConfigCache()");
-    if (gAudioFlingerClient != 0) {
-        gAudioFlingerClient->clearIoCache();
-    }
     {
         Mutex::Autolock _l(gLock);
+        if (gAudioFlingerClient != 0) {
+            gAudioFlingerClient->clearIoCache();
+        }
         gAudioFlinger.clear();
     }
     {
@@ -934,7 +1027,7 @@
     return aps->setAudioPortConfig(config);
 }
 
-status_t AudioSystem::addAudioPortCallback(const sp<AudioPortCallback>& callBack)
+status_t AudioSystem::addAudioPortCallback(const sp<AudioPortCallback>& callback)
 {
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     if (aps == 0) return PERMISSION_DENIED;
@@ -943,11 +1036,11 @@
     if (gAudioPolicyServiceClient == 0) {
         return NO_INIT;
     }
-    return gAudioPolicyServiceClient->addAudioPortCallback(callBack);
+    return gAudioPolicyServiceClient->addAudioPortCallback(callback);
 }
 
 /*static*/
-status_t AudioSystem::removeAudioPortCallback(const sp<AudioPortCallback>& callBack)
+status_t AudioSystem::removeAudioPortCallback(const sp<AudioPortCallback>& callback)
 {
     const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
     if (aps == 0) return PERMISSION_DENIED;
@@ -956,7 +1049,38 @@
     if (gAudioPolicyServiceClient == 0) {
         return NO_INIT;
     }
-    return gAudioPolicyServiceClient->removeAudioPortCallback(callBack);
+    return gAudioPolicyServiceClient->removeAudioPortCallback(callback);
+}
+
+status_t AudioSystem::addAudioDeviceCallback(
+        const sp<AudioDeviceCallback>& callback, audio_io_handle_t audioIo)
+{
+    const sp<AudioFlingerClient> afc = getAudioFlingerClient();
+    if (afc == 0) {
+        return NO_INIT;
+    }
+    return afc->addAudioDeviceCallback(callback, audioIo);
+}
+
+status_t AudioSystem::removeAudioDeviceCallback(
+        const sp<AudioDeviceCallback>& callback, audio_io_handle_t audioIo)
+{
+    const sp<AudioFlingerClient> afc = getAudioFlingerClient();
+    if (afc == 0) {
+        return NO_INIT;
+    }
+    return afc->removeAudioDeviceCallback(callback, audioIo);
+}
+
+audio_port_handle_t AudioSystem::getDeviceIdForIo(audio_io_handle_t audioIo)
+{
+    const sp<IAudioFlinger>& af = AudioSystem::get_audio_flinger();
+    if (af == 0) return PERMISSION_DENIED;
+    const sp<AudioIoDescriptor> desc = getIoDescriptor(audioIo);
+    if (desc == 0) {
+        return AUDIO_PORT_HANDLE_NONE;
+    }
+    return desc->getDeviceId();
 }
 
 status_t AudioSystem::acquireSoundTriggerSession(audio_session_t *session,
@@ -1008,25 +1132,25 @@
 // ---------------------------------------------------------------------------
 
 status_t AudioSystem::AudioPolicyServiceClient::addAudioPortCallback(
-        const sp<AudioPortCallback>& callBack)
+        const sp<AudioPortCallback>& callback)
 {
     Mutex::Autolock _l(mLock);
     for (size_t i = 0; i < mAudioPortCallbacks.size(); i++) {
-        if (mAudioPortCallbacks[i] == callBack) {
+        if (mAudioPortCallbacks[i] == callback) {
             return INVALID_OPERATION;
         }
     }
-    mAudioPortCallbacks.add(callBack);
+    mAudioPortCallbacks.add(callback);
     return NO_ERROR;
 }
 
 status_t AudioSystem::AudioPolicyServiceClient::removeAudioPortCallback(
-        const sp<AudioPortCallback>& callBack)
+        const sp<AudioPortCallback>& callback)
 {
     Mutex::Autolock _l(mLock);
     size_t i;
     for (i = 0; i < mAudioPortCallbacks.size(); i++) {
-        if (mAudioPortCallbacks[i] == callBack) {
+        if (mAudioPortCallbacks[i] == callback) {
             break;
         }
     }
@@ -1037,6 +1161,7 @@
     return NO_ERROR;
 }
 
+
 void AudioSystem::AudioPolicyServiceClient::onAudioPortListUpdate()
 {
     Mutex::Autolock _l(mLock);
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index bb47d3e..db316b0 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -234,6 +234,10 @@
             mAudioTrackThread->requestExitAndWait();
             mAudioTrackThread.clear();
         }
+        // No lock here: worst case we remove a NULL callback which will be a nop
+        if (mDeviceCallback != 0 && mOutput != AUDIO_IO_HANDLE_NONE) {
+            AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mOutput);
+        }
         IInterface::asBinder(mAudioTrack)->unlinkToDeath(mDeathNotifier, this);
         mAudioTrack.clear();
         mCblkMemory.clear();
@@ -1042,6 +1046,14 @@
     return mSelectedDeviceId;
 }
 
+audio_port_handle_t AudioTrack::getRoutedDeviceId() {
+    AutoMutex lock(mLock);
+    if (mOutput == AUDIO_IO_HANDLE_NONE) {
+        return AUDIO_PORT_HANDLE_NONE;
+    }
+    return AudioSystem::getDeviceIdForIo(mOutput);
+}
+
 status_t AudioTrack::attachAuxEffect(int effectId)
 {
     AutoMutex lock(mLock);
@@ -1071,6 +1083,9 @@
         return NO_INIT;
     }
 
+    if (mDeviceCallback != 0 && mOutput != AUDIO_IO_HANDLE_NONE) {
+        AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mOutput);
+    }
     audio_io_handle_t output;
     audio_stream_type_t streamType = mStreamType;
     audio_attributes_t *attr = (mStreamType == AUDIO_STREAM_DEFAULT) ? &mAttributes : NULL;
@@ -1375,6 +1390,10 @@
     mDeathNotifier = new DeathNotifier(this);
     IInterface::asBinder(mAudioTrack)->linkToDeath(mDeathNotifier, this);
 
+    if (mDeviceCallback != 0) {
+        AudioSystem::addAudioDeviceCallback(mDeviceCallback, mOutput);
+    }
+
     return NO_ERROR;
     }
 
@@ -2308,6 +2327,48 @@
     return mProxy->getUnderrunFrames();
 }
 
+status_t AudioTrack::addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback)
+{
+    if (callback == 0) {
+        ALOGW("%s adding NULL callback!", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    AutoMutex lock(mLock);
+    if (mDeviceCallback == callback) {
+        ALOGW("%s adding same callback!", __FUNCTION__);
+        return INVALID_OPERATION;
+    }
+    status_t status = NO_ERROR;
+    if (mOutput != AUDIO_IO_HANDLE_NONE) {
+        if (mDeviceCallback != 0) {
+            ALOGW("%s callback already present!", __FUNCTION__);
+            AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mOutput);
+        }
+        status = AudioSystem::addAudioDeviceCallback(callback, mOutput);
+    }
+    mDeviceCallback = callback;
+    return status;
+}
+
+status_t AudioTrack::removeAudioDeviceCallback(
+        const sp<AudioSystem::AudioDeviceCallback>& callback)
+{
+    if (callback == 0) {
+        ALOGW("%s removing NULL callback!", __FUNCTION__);
+        return BAD_VALUE;
+    }
+    AutoMutex lock(mLock);
+    if (mDeviceCallback != callback) {
+        ALOGW("%s removing different callback!", __FUNCTION__);
+        return INVALID_OPERATION;
+    }
+    if (mOutput != AUDIO_IO_HANDLE_NONE) {
+        AudioSystem::removeAudioDeviceCallback(mDeviceCallback, mOutput);
+    }
+    mDeviceCallback = 0;
+    return NO_ERROR;
+}
+
 // =========================================================================
 
 void AudioTrack::DeathNotifier::binderDied(const wp<IBinder>& who __unused)
diff --git a/media/libmedia/IAudioFlingerClient.cpp b/media/libmedia/IAudioFlingerClient.cpp
index a622241..3429d36 100644
--- a/media/libmedia/IAudioFlingerClient.cpp
+++ b/media/libmedia/IAudioFlingerClient.cpp
@@ -45,6 +45,7 @@
         data.writeInterfaceToken(IAudioFlingerClient::getInterfaceDescriptor());
         data.writeInt32(event);
         data.writeInt32((int32_t)ioDesc->mIoHandle);
+        data.write(&ioDesc->mPatch, sizeof(struct audio_patch));
         data.writeInt32(ioDesc->mSamplingRate);
         data.writeInt32(ioDesc->mFormat);
         data.writeInt32(ioDesc->mChannelMask);
@@ -67,6 +68,7 @@
             audio_io_config_event event = (audio_io_config_event)data.readInt32();
             sp<AudioIoDescriptor> ioDesc = new AudioIoDescriptor();
             ioDesc->mIoHandle = (audio_io_handle_t) data.readInt32();
+            data.read(&ioDesc->mPatch, sizeof(struct audio_patch));
             ioDesc->mSamplingRate = data.readInt32();
             ioDesc->mFormat = (audio_format_t) data.readInt32();
             ioDesc->mChannelMask = (audio_channel_mask_t) data.readInt32();
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 8b8dd78..2c4d801 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -500,6 +500,7 @@
         // mName will be set by concrete (non-virtual) subclass
         mDeathRecipient(new PMDeathRecipient(this))
 {
+    memset(&mPatch, 0, sizeof(struct audio_patch));
 }
 
 AudioFlinger::ThreadBase::~ThreadBase()
@@ -1930,6 +1931,7 @@
     switch (event) {
     case AUDIO_OUTPUT_OPENED:
     case AUDIO_OUTPUT_CONFIG_CHANGED:
+        desc->mPatch = mPatch;
         desc->mChannelMask = mChannelMask;
         desc->mSamplingRate = mSampleRate;
         desc->mFormat = mFormat;
@@ -3002,6 +3004,7 @@
         mEffectChains[i]->setDevice_l(type);
     }
     mOutDevice = type;
+    mPatch = *patch;
 
     if (mOutput->audioHwDev->version() >= AUDIO_DEVICE_API_VERSION_3_0) {
         audio_hw_device_t *hwDevice = mOutput->audioHwDev->hwDevice();
@@ -3028,6 +3031,7 @@
                 param.toString().string());
         *handle = AUDIO_PATCH_HANDLE_NONE;
     }
+    sendIoConfigEvent_l(AUDIO_OUTPUT_CONFIG_CHANGED);
     return status;
 }
 
@@ -6727,6 +6731,7 @@
     switch (event) {
     case AUDIO_INPUT_OPENED:
     case AUDIO_INPUT_CONFIG_CHANGED:
+        desc->mPatch = mPatch;
         desc->mChannelMask = mChannelMask;
         desc->mSamplingRate = mSampleRate;
         desc->mFormat = mFormat;
@@ -6884,6 +6889,7 @@
 
     // store new device and send to effects
     mInDevice = patch->sources[0].ext.device.type;
+    mPatch = *patch;
     for (size_t i = 0; i < mEffectChains.size(); i++) {
         mEffectChains[i]->setDevice_l(mInDevice);
     }
@@ -6936,6 +6942,8 @@
         *handle = AUDIO_PATCH_HANDLE_NONE;
     }
 
+    sendIoConfigEvent_l(AUDIO_INPUT_CONFIG_CHANGED);
+
     return status;
 }
 
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 8167bd1..0a5597f 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -426,6 +426,7 @@
                 bool                    mStandby;     // Whether thread is currently in standby.
                 audio_devices_t         mOutDevice;   // output device
                 audio_devices_t         mInDevice;    // input device
+                struct audio_patch      mPatch;
                 audio_source_t          mAudioSource;
 
                 const audio_io_handle_t mId;