diff --git a/audio/aidl/default/Android.bp b/audio/aidl/default/Android.bp
index f51f65e..d47b0b1 100644
--- a/audio/aidl/default/Android.bp
+++ b/audio/aidl/default/Android.bp
@@ -77,6 +77,7 @@
         "r_submix/ModuleRemoteSubmix.cpp",
         "r_submix/SubmixRoute.cpp",
         "r_submix/StreamRemoteSubmix.cpp",
+        "stub/DriverStubImpl.cpp",
         "stub/ModuleStub.cpp",
         "stub/StreamStub.cpp",
         "usb/ModuleUsb.cpp",
diff --git a/audio/aidl/default/include/core-impl/DriverStubImpl.h b/audio/aidl/default/include/core-impl/DriverStubImpl.h
new file mode 100644
index 0000000..40a9fea
--- /dev/null
+++ b/audio/aidl/default/include/core-impl/DriverStubImpl.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "core-impl/Stream.h"
+
+namespace aidl::android::hardware::audio::core {
+
+class DriverStubImpl : virtual public DriverInterface {
+  public:
+    explicit DriverStubImpl(const StreamContext& context);
+
+    ::android::status_t init() override;
+    ::android::status_t drain(StreamDescriptor::DrainMode) override;
+    ::android::status_t flush() override;
+    ::android::status_t pause() override;
+    ::android::status_t standby() override;
+    ::android::status_t start() override;
+    ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
+                                 int32_t* latencyMs) override;
+    void shutdown() override;
+
+  private:
+    const size_t mBufferSizeFrames;
+    const size_t mFrameSizeBytes;
+    const int mSampleRate;
+    const bool mIsAsynchronous;
+    const bool mIsInput;
+    bool mIsInitialized = false;  // Used for validating the state machine logic.
+    bool mIsStandby = true;       // Used for validating the state machine logic.
+    int64_t mStartTimeNs = 0;
+    long mFramesSinceStart = 0;
+};
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/Stream.h b/audio/aidl/default/include/core-impl/Stream.h
index 5dca739..f7b9269 100644
--- a/audio/aidl/default/include/core-impl/Stream.h
+++ b/audio/aidl/default/include/core-impl/Stream.h
@@ -133,6 +133,9 @@
     ReplyMQ* getReplyMQ() const { return mReplyMQ.get(); }
     int getTransientStateDelayMs() const { return mDebugParameters.transientStateDelayMs; }
     int getSampleRate() const { return mSampleRate; }
+    bool isInput() const {
+        return mFlags.getTag() == ::aidl::android::media::audio::common::AudioIoFlags::input;
+    }
     bool isValid() const;
     // 'reset' is called on a Binder thread when closing the stream. Does not use
     // locking because it only cleans MQ pointers which were also set on the Binder thread.
diff --git a/audio/aidl/default/include/core-impl/StreamPrimary.h b/audio/aidl/default/include/core-impl/StreamPrimary.h
index 600c377..4f19a46 100644
--- a/audio/aidl/default/include/core-impl/StreamPrimary.h
+++ b/audio/aidl/default/include/core-impl/StreamPrimary.h
@@ -16,25 +16,39 @@
 
 #pragma once
 
+#include <mutex>
 #include <vector>
 
+#include <android-base/thread_annotations.h>
+
+#include "DriverStubImpl.h"
 #include "StreamAlsa.h"
-#include "StreamSwitcher.h"
+#include "primary/PrimaryMixer.h"
 
 namespace aidl::android::hardware::audio::core {
 
 class StreamPrimary : public StreamAlsa {
   public:
-    StreamPrimary(StreamContext* context, const Metadata& metadata,
-                  const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices);
+    StreamPrimary(StreamContext* context, const Metadata& metadata);
 
+    // Methods of 'DriverInterface'.
+    ::android::status_t init() override;
+    ::android::status_t drain(StreamDescriptor::DrainMode mode) override;
+    ::android::status_t flush() override;
+    ::android::status_t pause() override;
+    ::android::status_t standby() override;
     ::android::status_t start() override;
     ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
                                  int32_t* latencyMs) override;
     ::android::status_t refinePosition(StreamDescriptor::Position* position) override;
+    void shutdown() override;
+
+    // Overridden methods of 'StreamCommonImpl', called on a Binder thread.
+    ndk::ScopedAStatus setConnectedDevices(const ConnectedDevices& devices) override;
 
   protected:
     std::vector<alsa::DeviceProfile> getDeviceProfiles() override;
+    bool isStubStream();
 
     const bool mIsAsynchronous;
     int64_t mStartTimeNs = 0;
@@ -42,12 +56,29 @@
     bool mSkipNextTransfer = false;
 
   private:
-    static std::pair<int, int> getCardAndDeviceId(
+    using AlsaDeviceId = std::pair<int, int>;
+
+    static constexpr StreamPrimary::AlsaDeviceId kDefaultCardAndDeviceId{
+            primary::PrimaryMixer::kAlsaCard, primary::PrimaryMixer::kAlsaDevice};
+    static constexpr StreamPrimary::AlsaDeviceId kStubDeviceId{
+            primary::PrimaryMixer::kInvalidAlsaCard, primary::PrimaryMixer::kInvalidAlsaDevice};
+
+    static AlsaDeviceId getCardAndDeviceId(
             const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices);
-    const std::pair<int, int> mCardAndDeviceId;
+    static bool useStubStream(bool isInput,
+                              const ::aidl::android::media::audio::common::AudioDevice& device);
+
+    bool isStubStreamOnWorker() const { return mCurrAlsaDeviceId == kStubDeviceId; }
+
+    DriverStubImpl mStubDriver;
+    mutable std::mutex mLock;
+    AlsaDeviceId mAlsaDeviceId GUARDED_BY(mLock) = kStubDeviceId;
+
+    // Used by the worker thread only.
+    AlsaDeviceId mCurrAlsaDeviceId = kStubDeviceId;
 };
 
-class StreamInPrimary final : public StreamIn, public StreamSwitcher, public StreamInHwGainHelper {
+class StreamInPrimary final : public StreamIn, public StreamPrimary, public StreamInHwGainHelper {
   public:
     friend class ndk::SharedRefBase;
     StreamInPrimary(
@@ -56,14 +87,6 @@
             const std::vector<::aidl::android::media::audio::common::MicrophoneInfo>& microphones);
 
   private:
-    static bool useStubStream(const ::aidl::android::media::audio::common::AudioDevice& device);
-
-    DeviceSwitchBehavior switchCurrentStream(
-            const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices)
-            override;
-    std::unique_ptr<StreamCommonInterfaceEx> createNewStream(
-            const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices,
-            StreamContext* context, const Metadata& metadata) override;
     void onClose(StreamDescriptor::State) override { defaultOnClose(); }
 
     ndk::ScopedAStatus getHwGain(std::vector<float>* _aidl_return) override;
@@ -71,7 +94,7 @@
 };
 
 class StreamOutPrimary final : public StreamOut,
-                               public StreamSwitcher,
+                               public StreamPrimary,
                                public StreamOutHwVolumeHelper {
   public:
     friend class ndk::SharedRefBase;
@@ -81,22 +104,10 @@
                              offloadInfo);
 
   private:
-    static bool useStubStream(const ::aidl::android::media::audio::common::AudioDevice& device);
-
-    DeviceSwitchBehavior switchCurrentStream(
-            const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices)
-            override;
-    std::unique_ptr<StreamCommonInterfaceEx> createNewStream(
-            const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices,
-            StreamContext* context, const Metadata& metadata) override;
     void onClose(StreamDescriptor::State) override { defaultOnClose(); }
 
     ndk::ScopedAStatus getHwVolume(std::vector<float>* _aidl_return) override;
     ndk::ScopedAStatus setHwVolume(const std::vector<float>& in_channelVolumes) override;
-
-    ndk::ScopedAStatus setConnectedDevices(
-            const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices)
-            override;
 };
 
 }  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/include/core-impl/StreamStub.h b/audio/aidl/default/include/core-impl/StreamStub.h
index 22b2020..cee44db 100644
--- a/audio/aidl/default/include/core-impl/StreamStub.h
+++ b/audio/aidl/default/include/core-impl/StreamStub.h
@@ -16,38 +16,15 @@
 
 #pragma once
 
+#include "core-impl/DriverStubImpl.h"
 #include "core-impl/Stream.h"
 
 namespace aidl::android::hardware::audio::core {
 
-class StreamStub : public StreamCommonImpl {
+class StreamStub : public StreamCommonImpl, public DriverStubImpl {
   public:
     StreamStub(StreamContext* context, const Metadata& metadata);
     ~StreamStub();
-
-    // Methods of 'DriverInterface'.
-    ::android::status_t init() override;
-    ::android::status_t drain(StreamDescriptor::DrainMode) override;
-    ::android::status_t flush() override;
-    ::android::status_t pause() override;
-    ::android::status_t standby() override;
-    ::android::status_t start() override;
-    ::android::status_t transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
-                                 int32_t* latencyMs) override;
-    void shutdown() override;
-
-  private:
-    const size_t mBufferSizeFrames;
-    const size_t mFrameSizeBytes;
-    const int mSampleRate;
-    const bool mIsAsynchronous;
-    const bool mIsInput;
-    bool mIsInitialized = false;  // Used for validating the state machine logic.
-    bool mIsStandby = true;       // Used for validating the state machine logic.
-
-    // Used by the worker thread.
-    int64_t mStartTimeNs = 0;
-    long mFramesSinceStart = 0;
 };
 
 class StreamInStub final : public StreamIn, public StreamStub {
diff --git a/audio/aidl/default/primary/PrimaryMixer.h b/audio/aidl/default/primary/PrimaryMixer.h
index 3806428..760d42f 100644
--- a/audio/aidl/default/primary/PrimaryMixer.h
+++ b/audio/aidl/default/primary/PrimaryMixer.h
@@ -16,20 +16,14 @@
 
 #pragma once
 
-#include <map>
-#include <memory>
-#include <mutex>
-#include <vector>
-
-#include <android-base/thread_annotations.h>
-#include <android/binder_auto_utils.h>
-
 #include "alsa/Mixer.h"
 
 namespace aidl::android::hardware::audio::core::primary {
 
 class PrimaryMixer : public alsa::Mixer {
   public:
+    static constexpr int kInvalidAlsaCard = -1;
+    static constexpr int kInvalidAlsaDevice = -1;
     static constexpr int kAlsaCard = 0;
     static constexpr int kAlsaDevice = 0;
 
diff --git a/audio/aidl/default/primary/StreamPrimary.cpp b/audio/aidl/default/primary/StreamPrimary.cpp
index 801bbb8..1176d05 100644
--- a/audio/aidl/default/primary/StreamPrimary.cpp
+++ b/audio/aidl/default/primary/StreamPrimary.cpp
@@ -25,9 +25,7 @@
 #include <error/Result.h>
 #include <error/expected_utils.h>
 
-#include "PrimaryMixer.h"
 #include "core-impl/StreamPrimary.h"
-#include "core-impl/StreamStub.h"
 
 using aidl::android::hardware::audio::common::SinkMetadata;
 using aidl::android::hardware::audio::common::SourceMetadata;
@@ -41,19 +39,49 @@
 
 namespace aidl::android::hardware::audio::core {
 
-const static constexpr std::pair<int, int> kDefaultCardAndDeviceId = {
-        primary::PrimaryMixer::kAlsaCard, primary::PrimaryMixer::kAlsaDevice};
-
-StreamPrimary::StreamPrimary(
-        StreamContext* context, const Metadata& metadata,
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices)
+StreamPrimary::StreamPrimary(StreamContext* context, const Metadata& metadata)
     : StreamAlsa(context, metadata, 3 /*readWriteRetries*/),
       mIsAsynchronous(!!getContext().getAsyncCallback()),
-      mCardAndDeviceId(getCardAndDeviceId(devices)) {
+      mStubDriver(getContext()) {
     context->startStreamDataProcessor();
 }
 
+::android::status_t StreamPrimary::init() {
+    RETURN_STATUS_IF_ERROR(mStubDriver.init());
+    return StreamAlsa::init();
+}
+
+::android::status_t StreamPrimary::drain(StreamDescriptor::DrainMode mode) {
+    return isStubStreamOnWorker() ? mStubDriver.drain(mode) : StreamAlsa::drain(mode);
+}
+
+::android::status_t StreamPrimary::flush() {
+    return isStubStreamOnWorker() ? mStubDriver.flush() : StreamAlsa::flush();
+}
+
+::android::status_t StreamPrimary::pause() {
+    return isStubStreamOnWorker() ? mStubDriver.pause() : StreamAlsa::pause();
+}
+
+::android::status_t StreamPrimary::standby() {
+    return isStubStreamOnWorker() ? mStubDriver.standby() : StreamAlsa::standby();
+}
+
 ::android::status_t StreamPrimary::start() {
+    bool isStub = true, shutdownAlsaStream = false;
+    {
+        std::lock_guard l(mLock);
+        isStub = mAlsaDeviceId == kStubDeviceId;
+        shutdownAlsaStream =
+                mCurrAlsaDeviceId != mAlsaDeviceId && mCurrAlsaDeviceId != kStubDeviceId;
+        mCurrAlsaDeviceId = mAlsaDeviceId;
+    }
+    if (shutdownAlsaStream) {
+        StreamAlsa::shutdown();  // Close currently opened ALSA devices.
+    }
+    if (isStub) {
+        return mStubDriver.start();
+    }
     RETURN_STATUS_IF_ERROR(StreamAlsa::start());
     mStartTimeNs = ::android::uptimeNanos();
     mFramesSinceStart = 0;
@@ -63,6 +91,9 @@
 
 ::android::status_t StreamPrimary::transfer(void* buffer, size_t frameCount,
                                             size_t* actualFrameCount, int32_t* latencyMs) {
+    if (isStubStreamOnWorker()) {
+        return mStubDriver.transfer(buffer, frameCount, actualFrameCount, latencyMs);
+    }
     // This is a workaround for the emulator implementation which has a host-side buffer
     // and is not being able to achieve real-time behavior similar to ADSPs (b/302587331).
     if (!mSkipNextTransfer) {
@@ -102,19 +133,52 @@
     return ::android::OK;
 }
 
+void StreamPrimary::shutdown() {
+    StreamAlsa::shutdown();
+    mStubDriver.shutdown();
+}
+
+ndk::ScopedAStatus StreamPrimary::setConnectedDevices(const ConnectedDevices& devices) {
+    LOG(DEBUG) << __func__ << ": " << ::android::internal::ToString(devices);
+    if (devices.size() > 1) {
+        LOG(ERROR) << __func__ << ": primary stream can only be connected to one device, got: "
+                   << devices.size();
+        return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+    }
+    {
+        const bool useStubDriver = devices.empty() || useStubStream(mIsInput, devices[0]);
+        std::lock_guard l(mLock);
+        mAlsaDeviceId = useStubDriver ? kStubDeviceId : getCardAndDeviceId(devices);
+    }
+    if (!devices.empty()) {
+        auto streamDataProcessor = getContext().getStreamDataProcessor().lock();
+        if (streamDataProcessor != nullptr) {
+            streamDataProcessor->setAudioDevice(devices[0]);
+        }
+    }
+    return StreamAlsa::setConnectedDevices(devices);
+}
+
 std::vector<alsa::DeviceProfile> StreamPrimary::getDeviceProfiles() {
-    return {alsa::DeviceProfile{.card = mCardAndDeviceId.first,
-                                .device = mCardAndDeviceId.second,
+    return {alsa::DeviceProfile{.card = mCurrAlsaDeviceId.first,
+                                .device = mCurrAlsaDeviceId.second,
                                 .direction = mIsInput ? PCM_IN : PCM_OUT,
                                 .isExternal = false}};
 }
 
-std::pair<int, int> StreamPrimary::getCardAndDeviceId(const std::vector<AudioDevice>& devices) {
+bool StreamPrimary::isStubStream() {
+    std::lock_guard l(mLock);
+    return mAlsaDeviceId == kStubDeviceId;
+}
+
+// static
+StreamPrimary::AlsaDeviceId StreamPrimary::getCardAndDeviceId(
+        const std::vector<AudioDevice>& devices) {
     if (devices.empty() || devices[0].address.getTag() != AudioDeviceAddress::id) {
         return kDefaultCardAndDeviceId;
     }
     std::string deviceAddress = devices[0].address.get<AudioDeviceAddress::id>();
-    std::pair<int, int> cardAndDeviceId;
+    AlsaDeviceId cardAndDeviceId;
     if (const size_t suffixPos = deviceAddress.rfind("CARD_");
         suffixPos == std::string::npos ||
         sscanf(deviceAddress.c_str() + suffixPos, "CARD_%d_DEV_%d", &cardAndDeviceId.first,
@@ -126,48 +190,28 @@
     return cardAndDeviceId;
 }
 
+// static
+bool StreamPrimary::useStubStream(
+        bool isInput, const ::aidl::android::media::audio::common::AudioDevice& device) {
+    static const bool kSimulateInput =
+            GetBoolProperty("ro.boot.audio.tinyalsa.simulate_input", false);
+    static const bool kSimulateOutput =
+            GetBoolProperty("ro.boot.audio.tinyalsa.ignore_output", false);
+    if (isInput) {
+        return kSimulateInput || device.type.type == AudioDeviceType::IN_TELEPHONY_RX ||
+               device.type.type == AudioDeviceType::IN_FM_TUNER ||
+               device.type.connection == AudioDeviceDescription::CONNECTION_BUS /*deprecated */;
+    }
+    return kSimulateOutput || device.type.type == AudioDeviceType::OUT_TELEPHONY_TX ||
+           device.type.connection == AudioDeviceDescription::CONNECTION_BUS /*deprecated*/;
+}
+
 StreamInPrimary::StreamInPrimary(StreamContext&& context, const SinkMetadata& sinkMetadata,
                                  const std::vector<MicrophoneInfo>& microphones)
     : StreamIn(std::move(context), microphones),
-      StreamSwitcher(&mContextInstance, sinkMetadata),
+      StreamPrimary(&mContextInstance, sinkMetadata),
       StreamInHwGainHelper(&mContextInstance) {}
 
-bool StreamInPrimary::useStubStream(const AudioDevice& device) {
-    static const bool kSimulateInput =
-            GetBoolProperty("ro.boot.audio.tinyalsa.simulate_input", false);
-    return kSimulateInput || device.type.type == AudioDeviceType::IN_TELEPHONY_RX ||
-           device.type.type == AudioDeviceType::IN_FM_TUNER ||
-           device.type.connection == AudioDeviceDescription::CONNECTION_BUS /*deprecated */;
-}
-
-StreamSwitcher::DeviceSwitchBehavior StreamInPrimary::switchCurrentStream(
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices) {
-    LOG(DEBUG) << __func__;
-    if (devices.size() > 1) {
-        LOG(ERROR) << __func__ << ": primary stream can only be connected to one device, got: "
-                   << devices.size();
-        return DeviceSwitchBehavior::UNSUPPORTED_DEVICES;
-    }
-    if (devices.empty() || useStubStream(devices[0]) == isStubStream()) {
-        return DeviceSwitchBehavior::USE_CURRENT_STREAM;
-    }
-    return DeviceSwitchBehavior::CREATE_NEW_STREAM;
-}
-
-std::unique_ptr<StreamCommonInterfaceEx> StreamInPrimary::createNewStream(
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices,
-        StreamContext* context, const Metadata& metadata) {
-    if (devices.empty()) {
-        LOG(FATAL) << __func__ << ": called with empty devices";  // see 'switchCurrentStream'
-    }
-    if (useStubStream(devices[0])) {
-        return std::unique_ptr<StreamCommonInterfaceEx>(
-                new InnerStreamWrapper<StreamStub>(context, metadata));
-    }
-    return std::unique_ptr<StreamCommonInterfaceEx>(
-            new InnerStreamWrapper<StreamPrimary>(context, metadata, devices));
-}
-
 ndk::ScopedAStatus StreamInPrimary::getHwGain(std::vector<float>* _aidl_return) {
     if (isStubStream()) {
         return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
@@ -201,44 +245,9 @@
 StreamOutPrimary::StreamOutPrimary(StreamContext&& context, const SourceMetadata& sourceMetadata,
                                    const std::optional<AudioOffloadInfo>& offloadInfo)
     : StreamOut(std::move(context), offloadInfo),
-      StreamSwitcher(&mContextInstance, sourceMetadata),
+      StreamPrimary(&mContextInstance, sourceMetadata),
       StreamOutHwVolumeHelper(&mContextInstance) {}
 
-bool StreamOutPrimary::useStubStream(const AudioDevice& device) {
-    static const bool kSimulateOutput =
-            GetBoolProperty("ro.boot.audio.tinyalsa.ignore_output", false);
-    return kSimulateOutput || device.type.type == AudioDeviceType::OUT_TELEPHONY_TX ||
-           device.type.connection == AudioDeviceDescription::CONNECTION_BUS /*deprecated*/;
-}
-
-StreamSwitcher::DeviceSwitchBehavior StreamOutPrimary::switchCurrentStream(
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices) {
-    LOG(DEBUG) << __func__;
-    if (devices.size() > 1) {
-        LOG(ERROR) << __func__ << ": primary stream can only be connected to one device, got: "
-                   << devices.size();
-        return DeviceSwitchBehavior::UNSUPPORTED_DEVICES;
-    }
-    if (devices.empty() || useStubStream(devices[0]) == isStubStream()) {
-        return DeviceSwitchBehavior::USE_CURRENT_STREAM;
-    }
-    return DeviceSwitchBehavior::CREATE_NEW_STREAM;
-}
-
-std::unique_ptr<StreamCommonInterfaceEx> StreamOutPrimary::createNewStream(
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices,
-        StreamContext* context, const Metadata& metadata) {
-    if (devices.empty()) {
-        LOG(FATAL) << __func__ << ": called with empty devices";  // see 'switchCurrentStream'
-    }
-    if (useStubStream(devices[0])) {
-        return std::unique_ptr<StreamCommonInterfaceEx>(
-                new InnerStreamWrapper<StreamStub>(context, metadata));
-    }
-    return std::unique_ptr<StreamCommonInterfaceEx>(
-            new InnerStreamWrapper<StreamPrimary>(context, metadata, devices));
-}
-
 ndk::ScopedAStatus StreamOutPrimary::getHwVolume(std::vector<float>* _aidl_return) {
     if (isStubStream()) {
         return ndk::ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
@@ -264,15 +273,4 @@
     return ndk::ScopedAStatus::ok();
 }
 
-ndk::ScopedAStatus StreamOutPrimary::setConnectedDevices(
-        const std::vector<::aidl::android::media::audio::common::AudioDevice>& devices) {
-    if (!devices.empty()) {
-        auto streamDataProcessor = mContextInstance.getStreamDataProcessor().lock();
-        if (streamDataProcessor != nullptr) {
-            streamDataProcessor->setAudioDevice(devices[0]);
-        }
-    }
-    return StreamSwitcher::setConnectedDevices(devices);
-}
-
 }  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/stub/DriverStubImpl.cpp b/audio/aidl/default/stub/DriverStubImpl.cpp
new file mode 100644
index 0000000..beb0114
--- /dev/null
+++ b/audio/aidl/default/stub/DriverStubImpl.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cmath>
+
+#define LOG_TAG "AHAL_Stream"
+#include <android-base/logging.h>
+#include <audio_utils/clock.h>
+
+#include "core-impl/DriverStubImpl.h"
+
+namespace aidl::android::hardware::audio::core {
+
+DriverStubImpl::DriverStubImpl(const StreamContext& context)
+    : mBufferSizeFrames(context.getBufferSizeInFrames()),
+      mFrameSizeBytes(context.getFrameSize()),
+      mSampleRate(context.getSampleRate()),
+      mIsAsynchronous(!!context.getAsyncCallback()),
+      mIsInput(context.isInput()) {}
+
+::android::status_t DriverStubImpl::init() {
+    mIsInitialized = true;
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::drain(StreamDescriptor::DrainMode) {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    if (!mIsInput) {
+        if (!mIsAsynchronous) {
+            static constexpr float kMicrosPerSecond = MICROS_PER_SECOND;
+            const size_t delayUs = static_cast<size_t>(
+                    std::roundf(mBufferSizeFrames * kMicrosPerSecond / mSampleRate));
+            usleep(delayUs);
+        } else {
+            usleep(500);
+        }
+    }
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::flush() {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::pause() {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::standby() {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    mIsStandby = true;
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::start() {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    mIsStandby = false;
+    mStartTimeNs = ::android::uptimeNanos();
+    mFramesSinceStart = 0;
+    return ::android::OK;
+}
+
+::android::status_t DriverStubImpl::transfer(void* buffer, size_t frameCount,
+                                             size_t* actualFrameCount, int32_t*) {
+    if (!mIsInitialized) {
+        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
+    }
+    if (mIsStandby) {
+        LOG(FATAL) << __func__ << ": must not happen while in standby";
+    }
+    *actualFrameCount = frameCount;
+    if (mIsAsynchronous) {
+        usleep(500);
+    } else {
+        mFramesSinceStart += *actualFrameCount;
+        const long bufferDurationUs = (*actualFrameCount) * MICROS_PER_SECOND / mSampleRate;
+        const auto totalDurationUs =
+                (::android::uptimeNanos() - mStartTimeNs) / NANOS_PER_MICROSECOND;
+        const long totalOffsetUs =
+                mFramesSinceStart * MICROS_PER_SECOND / mSampleRate - totalDurationUs;
+        LOG(VERBOSE) << __func__ << ": totalOffsetUs " << totalOffsetUs;
+        if (totalOffsetUs > 0) {
+            const long sleepTimeUs = std::min(totalOffsetUs, bufferDurationUs);
+            LOG(VERBOSE) << __func__ << ": sleeping for " << sleepTimeUs << " us";
+            usleep(sleepTimeUs);
+        }
+    }
+    if (mIsInput) {
+        uint8_t* byteBuffer = static_cast<uint8_t*>(buffer);
+        for (size_t i = 0; i < frameCount * mFrameSizeBytes; ++i) {
+            byteBuffer[i] = std::rand() % 255;
+        }
+    }
+    return ::android::OK;
+}
+
+void DriverStubImpl::shutdown() {
+    mIsInitialized = false;
+}
+
+}  // namespace aidl::android::hardware::audio::core
diff --git a/audio/aidl/default/stub/StreamStub.cpp b/audio/aidl/default/stub/StreamStub.cpp
index a3d99a8..f6c87e1 100644
--- a/audio/aidl/default/stub/StreamStub.cpp
+++ b/audio/aidl/default/stub/StreamStub.cpp
@@ -32,110 +32,12 @@
 namespace aidl::android::hardware::audio::core {
 
 StreamStub::StreamStub(StreamContext* context, const Metadata& metadata)
-    : StreamCommonImpl(context, metadata),
-      mBufferSizeFrames(getContext().getBufferSizeInFrames()),
-      mFrameSizeBytes(getContext().getFrameSize()),
-      mSampleRate(getContext().getSampleRate()),
-      mIsAsynchronous(!!getContext().getAsyncCallback()),
-      mIsInput(isInput(metadata)) {}
+    : StreamCommonImpl(context, metadata), DriverStubImpl(getContext()) {}
 
 StreamStub::~StreamStub() {
     cleanupWorker();
 }
 
-::android::status_t StreamStub::init() {
-    mIsInitialized = true;
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::drain(StreamDescriptor::DrainMode) {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    if (!mIsInput) {
-        if (!mIsAsynchronous) {
-            static constexpr float kMicrosPerSecond = MICROS_PER_SECOND;
-            const size_t delayUs = static_cast<size_t>(
-                    std::roundf(mBufferSizeFrames * kMicrosPerSecond / mSampleRate));
-            usleep(delayUs);
-        } else {
-            usleep(500);
-        }
-    }
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::flush() {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::pause() {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::standby() {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    mIsStandby = true;
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::start() {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    mIsStandby = false;
-    mStartTimeNs = ::android::uptimeNanos();
-    mFramesSinceStart = 0;
-    return ::android::OK;
-}
-
-::android::status_t StreamStub::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
-                                         int32_t*) {
-    if (!mIsInitialized) {
-        LOG(FATAL) << __func__ << ": must not happen for an uninitialized driver";
-    }
-    if (mIsStandby) {
-        LOG(FATAL) << __func__ << ": must not happen while in standby";
-    }
-    *actualFrameCount = frameCount;
-    if (mIsAsynchronous) {
-        usleep(500);
-    } else {
-        mFramesSinceStart += *actualFrameCount;
-        const long bufferDurationUs =
-                (*actualFrameCount) * MICROS_PER_SECOND / mContext.getSampleRate();
-        const auto totalDurationUs =
-                (::android::uptimeNanos() - mStartTimeNs) / NANOS_PER_MICROSECOND;
-        const long totalOffsetUs =
-                mFramesSinceStart * MICROS_PER_SECOND / mContext.getSampleRate() - totalDurationUs;
-        LOG(VERBOSE) << __func__ << ": totalOffsetUs " << totalOffsetUs;
-        if (totalOffsetUs > 0) {
-            const long sleepTimeUs = std::min(totalOffsetUs, bufferDurationUs);
-            LOG(VERBOSE) << __func__ << ": sleeping for " << sleepTimeUs << " us";
-            usleep(sleepTimeUs);
-        }
-    }
-    if (mIsInput) {
-        uint8_t* byteBuffer = static_cast<uint8_t*>(buffer);
-        for (size_t i = 0; i < frameCount * mFrameSizeBytes; ++i) {
-            byteBuffer[i] = std::rand() % 255;
-        }
-    }
-    return ::android::OK;
-}
-
-void StreamStub::shutdown() {
-    mIsInitialized = false;
-}
-
 StreamInStub::StreamInStub(StreamContext&& context, const SinkMetadata& sinkMetadata,
                            const std::vector<MicrophoneInfo>& microphones)
     : StreamIn(std::move(context), microphones), StreamStub(&mContextInstance, sinkMetadata) {}