diff --git a/audio/aidl/aidl_api/android.hardware.audio.core/current/android/hardware/audio/core/IModule.aidl b/audio/aidl/aidl_api/android.hardware.audio.core/current/android/hardware/audio/core/IModule.aidl
index e14e9c0..07a85f8 100644
--- a/audio/aidl/aidl_api/android.hardware.audio.core/current/android/hardware/audio/core/IModule.aidl
+++ b/audio/aidl/aidl_api/android.hardware.audio.core/current/android/hardware/audio/core/IModule.aidl
@@ -74,6 +74,7 @@
   boolean supportsVariableLatency();
   int getAAudioMixerBurstCount();
   int getAAudioHardwareBurstMinUsec();
+  void prepareToDisconnectExternalDevice(int portId);
   const int DEFAULT_AAUDIO_MIXER_BURST_COUNT = 2;
   const int DEFAULT_AAUDIO_HARDWARE_BURST_MIN_DURATION_US = 1000;
   @VintfStability
diff --git a/audio/aidl/android/hardware/audio/core/IModule.aidl b/audio/aidl/android/hardware/audio/core/IModule.aidl
index e736c32..2d4d283 100644
--- a/audio/aidl/android/hardware/audio/core/IModule.aidl
+++ b/audio/aidl/android/hardware/audio/core/IModule.aidl
@@ -206,8 +206,10 @@
      * after successful connection of an external device.
      *
      * Handling of a disconnect is done in a reverse order:
-     *  1. Reset port configuration using the 'resetAudioPortConfig' method.
-     *  2. Release the connected device port by calling the 'disconnectExternalDevice'
+     *  1. Notify the HAL module to prepare for device disconnection using
+     *     'prepareToDisconnectExternalDevice' method.
+     *  2. Reset port configuration using the 'resetAudioPortConfig' method.
+     *  3. Release the connected device port by calling the 'disconnectExternalDevice'
      *     method. This also removes the audio routes associated with this
      *     device port.
      *
@@ -234,11 +236,15 @@
      * instance previously instantiated using the 'connectExternalDevice'
      * method.
      *
-     * The framework will call this method before closing streams and resetting
-     * patches. This call can be used by the HAL module to prepare itself to
-     * device disconnection. If the HAL module indicates an error after the first
-     * call, the framework will call this method once again after closing associated
-     * streams and patches.
+     * On AIDL HAL v1, the framework will call this method before closing streams
+     * and resetting patches. This call can be used by the HAL module to prepare
+     * itself to device disconnection. If the HAL module indicates an error after
+     * the first call, the framework will call this method once again after closing
+     * associated streams and patches.
+     *
+     * On AIDL HAL v2 and later, the framework will call 'prepareToDisconnectExternalDevice'
+     * method to notify the HAL module to prepare itself for device disconnection. The
+     * framework will only call this method after closing associated streams and patches.
      *
      * @throws EX_ILLEGAL_ARGUMENT In the following cases:
      *                             - If the port can not be found by the ID.
@@ -912,4 +918,20 @@
      * @throw EX_UNSUPPORTED_OPERATION If the module does not support aaudio MMAP.
      */
     int getAAudioHardwareBurstMinUsec();
+
+    /**
+     * Notify the HAL module to prepare for disconnecting an external device.
+     *
+     * This method is used to inform the HAL module that 'disconnectExternalDevice' will be
+     * called soon. The HAL module can rely on this method to abort active data operations
+     * early. The 'portId' must be of a connected device Port instance previously instantiated
+     * using 'connectExternalDevice' method. 'disconnectExternalDevice' method will be called
+     * soon after this method with the same 'portId'.
+     *
+     * @param portId The ID of the audio port that is about to disconnect
+     * @throws EX_ILLEGAL_ARGUMENT In the following cases:
+     *                             - If the port can not be found by the ID.
+     *                             - If this is not a connected device port.
+     */
+    void prepareToDisconnectExternalDevice(int portId);
 }
diff --git a/audio/aidl/default/Configuration.cpp b/audio/aidl/default/Configuration.cpp
index d63e353..2a8e58f 100644
--- a/audio/aidl/default/Configuration.cpp
+++ b/audio/aidl/default/Configuration.cpp
@@ -321,9 +321,9 @@
 //
 // Mix ports:
 //  * "r_submix output", maximum 10 opened streams, maximum 10 active streams
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
+//    - profile PCM 16-bit; STEREO; 8000, 11025, 16000, 32000, 44100, 48000
 //  * "r_submix input", maximum 10 opened streams, maximum 10 active streams
-//    - profile PCM 16-bit; MONO, STEREO; 8000, 11025, 16000, 32000, 44100, 48000
+//    - profile PCM 16-bit; STEREO; 8000, 11025, 16000, 32000, 44100, 48000
 //
 // Routes:
 //  "r_submix output" -> "Remote Submix Out"
diff --git a/audio/aidl/default/Module.cpp b/audio/aidl/default/Module.cpp
index 89e3d99..6c4d7ac 100644
--- a/audio/aidl/default/Module.cpp
+++ b/audio/aidl/default/Module.cpp
@@ -758,6 +758,28 @@
     return ndk::ScopedAStatus::ok();
 }
 
+ndk::ScopedAStatus Module::prepareToDisconnectExternalDevice(int32_t in_portId) {
+    auto& ports = getConfig().ports;
+    auto portIt = findById<AudioPort>(ports, in_portId);
+    if (portIt == ports.end()) {
+        LOG(ERROR) << __func__ << ": port id " << in_portId << " not found";
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+    if (portIt->ext.getTag() != AudioPortExt::Tag::device) {
+        LOG(ERROR) << __func__ << ": port id " << in_portId << " is not a device port";
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+    auto connectedPortsIt = mConnectedDevicePorts.find(in_portId);
+    if (connectedPortsIt == mConnectedDevicePorts.end()) {
+        LOG(ERROR) << __func__ << ": port id " << in_portId << " is not a connected device port";
+        return ndk::ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+
+    onPrepareToDisconnectExternalDevice(*portIt);
+
+    return ndk::ScopedAStatus::ok();
+}
+
 ndk::ScopedAStatus Module::getAudioPatches(std::vector<AudioPatch>* _aidl_return) {
     *_aidl_return = getConfig().patches;
     LOG(DEBUG) << __func__ << ": returning " << _aidl_return->size() << " patches";
@@ -1537,6 +1559,11 @@
     LOG(DEBUG) << __func__ << ": do nothing and return";
 }
 
+void Module::onPrepareToDisconnectExternalDevice(
+        const ::aidl::android::media::audio::common::AudioPort& audioPort __unused) {
+    LOG(DEBUG) << __func__ << ": do nothing and return";
+}
+
 ndk::ScopedAStatus Module::onMasterMuteChanged(bool mute __unused) {
     LOG(VERBOSE) << __func__ << ": do nothing and return ok";
     return ndk::ScopedAStatus::ok();
diff --git a/audio/aidl/default/include/core-impl/Module.h b/audio/aidl/default/include/core-impl/Module.h
index caf43f1..572b597 100644
--- a/audio/aidl/default/include/core-impl/Module.h
+++ b/audio/aidl/default/include/core-impl/Module.h
@@ -70,6 +70,7 @@
             const ::aidl::android::media::audio::common::AudioPort& in_templateIdAndAdditionalData,
             ::aidl::android::media::audio::common::AudioPort* _aidl_return) override;
     ndk::ScopedAStatus disconnectExternalDevice(int32_t in_portId) override;
+    ndk::ScopedAStatus prepareToDisconnectExternalDevice(int32_t in_portId) override;
     ndk::ScopedAStatus getAudioPatches(std::vector<AudioPatch>* _aidl_return) override;
     ndk::ScopedAStatus getAudioPort(
             int32_t in_portId,
@@ -195,6 +196,8 @@
             const std::vector<::aidl::android::media::audio::common::AudioPortConfig*>& sinks);
     virtual void onExternalDeviceConnectionChanged(
             const ::aidl::android::media::audio::common::AudioPort& audioPort, bool connected);
+    virtual void onPrepareToDisconnectExternalDevice(
+            const ::aidl::android::media::audio::common::AudioPort& audioPort);
     virtual ndk::ScopedAStatus onMasterMuteChanged(bool mute);
     virtual ndk::ScopedAStatus onMasterVolumeChanged(float volume);
     virtual std::vector<::aidl::android::media::audio::common::MicrophoneInfo> getMicrophoneInfos();
diff --git a/audio/aidl/default/r_submix/ModuleRemoteSubmix.cpp b/audio/aidl/default/r_submix/ModuleRemoteSubmix.cpp
index 3e8dd7c..2f42889 100644
--- a/audio/aidl/default/r_submix/ModuleRemoteSubmix.cpp
+++ b/audio/aidl/default/r_submix/ModuleRemoteSubmix.cpp
@@ -112,7 +112,7 @@
     static constexpr int32_t kMaxLatencyMs =
             (r_submix::kDefaultPipeSizeInFrames * 1000) / r_submix::kDefaultSampleRateHz;
     static constexpr int32_t kMinLatencyMs = kMaxLatencyMs / r_submix::kDefaultPipePeriodCount;
-    return (kMaxLatencyMs + kMinLatencyMs) / 2;
+    return kMinLatencyMs;
 }
 
 }  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
index 6258c93..d238aa4 100644
--- a/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
+++ b/audio/aidl/default/r_submix/StreamRemoteSubmix.cpp
@@ -73,10 +73,8 @@
         LOG(ERROR) << __func__ << ": nullptr sink when opening stream";
         return ::android::NO_INIT;
     }
-    // If the sink has been shutdown or pipe recreation is forced, delete the pipe and
-    // recreate it.
-    if (sink->isShutdown()) {
-        LOG(DEBUG) << __func__ << ": Non-nullptr shut down sink when opening stream";
+    if ((!mIsInput || mCurrentRoute->isStreamInOpen()) && sink->isShutdown()) {
+        LOG(DEBUG) << __func__ << ": Shut down sink when opening stream";
         if (::android::OK != mCurrentRoute->resetPipe()) {
             LOG(ERROR) << __func__ << ": reset pipe failed";
             return ::android::NO_INIT;
diff --git a/audio/aidl/default/r_submix/SubmixRoute.cpp b/audio/aidl/default/r_submix/SubmixRoute.cpp
index f04e607..235c9a3 100644
--- a/audio/aidl/default/r_submix/SubmixRoute.cpp
+++ b/audio/aidl/default/r_submix/SubmixRoute.cpp
@@ -98,6 +98,9 @@
         }
         mStreamInStandby = true;
         mReadCounterFrames = 0;
+        if (mSink != nullptr) {
+            mSink->shutdown(false);
+        }
     } else {
         mStreamOutOpen = true;
     }
@@ -106,8 +109,7 @@
 void SubmixRoute::closeStream(bool isInput) {
     std::lock_guard guard(mLock);
     if (isInput) {
-        mInputRefCount--;
-        if (mInputRefCount == 0) {
+        if (--mInputRefCount == 0) {
             mStreamInOpen = false;
             if (mSink != nullptr) {
                 mSink->shutdown(true);
diff --git a/audio/aidl/vts/TestUtils.h b/audio/aidl/vts/TestUtils.h
index e9f3251..515b8a2 100644
--- a/audio/aidl/vts/TestUtils.h
+++ b/audio/aidl/vts/TestUtils.h
@@ -69,6 +69,23 @@
                                          << "\n  but is has completed with: " << status;
 }
 
+inline ::testing::AssertionResult assertIsOkOrUnknownTransaction(
+        const char* expr, const ::ndk::ScopedAStatus& status) {
+    if (status.getStatus() == STATUS_UNKNOWN_TRANSACTION) {
+        return ::testing::AssertionSuccess();
+    }
+    return assertIsOk(expr, status);
+}
+
+inline ::testing::AssertionResult assertResultOrUnknownTransaction(
+        const char* exp_expr, const char* act_expr, int32_t expected,
+        const ::ndk::ScopedAStatus& status) {
+    if (status.getStatus() == STATUS_UNKNOWN_TRANSACTION) {
+        return ::testing::AssertionSuccess();
+    }
+    return assertResult(exp_expr, act_expr, expected, status);
+}
+
 }  // namespace detail
 
 }  // namespace android::hardware::audio::common::testing
@@ -93,3 +110,15 @@
             GTEST_SKIP() << "Skip data path for offload";                                        \
         }                                                                                        \
     })
+
+// Test that the transaction status 'isOk' if it is a known transaction
+#define EXPECT_IS_OK_OR_UNKNOWN_TRANSACTION(ret)                                                 \
+    EXPECT_PRED_FORMAT1(                                                                         \
+            ::android::hardware::audio::common::testing::detail::assertIsOkOrUnknownTransaction, \
+            ret)
+
+// Test that the transaction status is as expected if it is a known transaction
+#define EXPECT_STATUS_OR_UNKNOWN_TRANSACTION(expected, ret)                                        \
+    EXPECT_PRED_FORMAT2(                                                                           \
+            ::android::hardware::audio::common::testing::detail::assertResultOrUnknownTransaction, \
+            expected, ret)
diff --git a/audio/aidl/vts/VtsHalAudioCoreModuleTargetTest.cpp b/audio/aidl/vts/VtsHalAudioCoreModuleTargetTest.cpp
index 697aae9..f91795b 100644
--- a/audio/aidl/vts/VtsHalAudioCoreModuleTargetTest.cpp
+++ b/audio/aidl/vts/VtsHalAudioCoreModuleTargetTest.cpp
@@ -573,6 +573,8 @@
     WithDevicePortConnectedState& operator=(const WithDevicePortConnectedState&) = delete;
     ~WithDevicePortConnectedState() {
         if (mModule != nullptr) {
+            EXPECT_IS_OK_OR_UNKNOWN_TRANSACTION(mModule->prepareToDisconnectExternalDevice(getId()))
+                    << "when preparing to disconnect device port ID " << getId();
             EXPECT_IS_OK(mModule->disconnectExternalDevice(getId()))
                     << "when disconnecting device port ID " << getId();
         }
@@ -1753,6 +1755,9 @@
         ScopedAStatus status = module->connectExternalDevice(portWithData, &connectedPort);
         EXPECT_STATUS(EX_ILLEGAL_STATE, status) << "static port " << portWithData.toString();
         if (status.isOk()) {
+            EXPECT_IS_OK_OR_UNKNOWN_TRANSACTION(
+                    module->prepareToDisconnectExternalDevice(connectedPort.id))
+                    << "when preparing to disconnect device port ID " << connectedPort.id;
             EXPECT_IS_OK(module->disconnectExternalDevice(connectedPort.id))
                     << "when disconnecting device port ID " << connectedPort.id;
         }
@@ -1782,6 +1787,9 @@
         invalidPort.id = portId;
         EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->connectExternalDevice(invalidPort, &ignored))
                 << "port ID " << portId << ", when setting CONNECTED state";
+        EXPECT_STATUS_OR_UNKNOWN_TRANSACTION(EX_ILLEGAL_ARGUMENT,
+                                             module->prepareToDisconnectExternalDevice(portId))
+                << "port ID " << portId << ", when preparing to disconnect";
         EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->disconnectExternalDevice(portId))
                 << "port ID " << portId << ", when setting DISCONNECTED state";
     }
@@ -1792,6 +1800,9 @@
         if (port.ext.getTag() != AudioPortExt::Tag::device) {
             EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->connectExternalDevice(port, &ignored))
                     << "non-device port ID " << port.id << " when setting CONNECTED state";
+            EXPECT_STATUS_OR_UNKNOWN_TRANSACTION(EX_ILLEGAL_ARGUMENT,
+                                                 module->prepareToDisconnectExternalDevice(port.id))
+                    << "non-device port ID " << port.id << " when preparing to disconnect";
             EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->disconnectExternalDevice(port.id))
                     << "non-device port ID " << port.id << " when setting DISCONNECTED state";
         } else {
@@ -1800,6 +1811,10 @@
                 EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->connectExternalDevice(port, &ignored))
                         << "for a permanently attached device port ID " << port.id
                         << " when setting CONNECTED state";
+                EXPECT_STATUS_OR_UNKNOWN_TRANSACTION(
+                        EX_ILLEGAL_ARGUMENT, module->prepareToDisconnectExternalDevice(port.id))
+                        << "for a permanently attached device port ID " << port.id
+                        << " when preparing to disconnect";
                 EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->disconnectExternalDevice(port.id))
                         << "for a permanently attached device port ID " << port.id
                         << " when setting DISCONNECTED state";
@@ -1817,6 +1832,9 @@
         GTEST_SKIP() << "No external devices in the module.";
     }
     for (const auto& port : ports) {
+        EXPECT_STATUS_OR_UNKNOWN_TRANSACTION(EX_ILLEGAL_ARGUMENT,
+                                             module->prepareToDisconnectExternalDevice(port.id))
+                << "when preparing to disconnect already disconnected device port ID " << port.id;
         EXPECT_STATUS(EX_ILLEGAL_ARGUMENT, module->disconnectExternalDevice(port.id))
                 << "when disconnecting already disconnected device port ID " << port.id;
         AudioPort portWithData = GenerateUniqueDeviceAddress(port);
@@ -1851,6 +1869,10 @@
             // Our test assumes that 'getAudioPort' returns at least one profile, and it
             // is not a dynamic profile.
             ASSERT_NO_FATAL_FAILURE(config.SetUp(module.get()));
+            EXPECT_IS_OK_OR_UNKNOWN_TRANSACTION(
+                    module->prepareToDisconnectExternalDevice(portConnected.getId()))
+                    << "when preparing to disconnect device port ID " << port.id
+                    << " with active configuration " << config.getId();
             EXPECT_STATUS(EX_ILLEGAL_STATE, module->disconnectExternalDevice(portConnected.getId()))
                     << "when trying to disconnect device port ID " << port.id
                     << " with active configuration " << config.getId();