diff --git a/services/audioflinger/DeviceEffectManager.cpp b/services/audioflinger/DeviceEffectManager.cpp
index feae97e..7cb9329 100644
--- a/services/audioflinger/DeviceEffectManager.cpp
+++ b/services/audioflinger/DeviceEffectManager.cpp
@@ -71,10 +71,15 @@
 
 void DeviceEffectManager::onReleaseAudioPatch(audio_patch_handle_t handle) {
     ALOGV("%s", __func__);
+    // Keep a reference on disconnected handle to delay destruction without lock held.
+    std::vector<sp<IAfEffectHandle>> disconnectedHandles{};
     audio_utils::lock_guard _l(mutex());
     for (auto& effectProxies : mDeviceEffects) {
         for (auto& effect : effectProxies.second) {
-            effect->onReleasePatch(handle);
+            sp<IAfEffectHandle> disconnectedHandle = effect->onReleasePatch(handle);
+            if (disconnectedHandle != nullptr) {
+                disconnectedHandles.push_back(std::move(disconnectedHandle));
+            }
         }
     }
 }
diff --git a/services/audioflinger/Effects.cpp b/services/audioflinger/Effects.cpp
index 973b2ab..0405035 100644
--- a/services/audioflinger/Effects.cpp
+++ b/services/audioflinger/Effects.cpp
@@ -1760,6 +1760,9 @@
         const sp<media::IEffectClient>& effectClient,
         int32_t priority, bool notifyFramesProcessed)
 {
+    if (client == nullptr && effectClient == nullptr) {
+        return sp<InternalEffectHandle>::make(effect, notifyFramesProcessed);
+    }
     return sp<EffectHandle>::make(
             effect, client, effectClient, priority, notifyFramesProcessed);
 }
@@ -1767,12 +1770,14 @@
 EffectHandle::EffectHandle(const sp<IAfEffectBase>& effect,
                                          const sp<Client>& client,
                                          const sp<media::IEffectClient>& effectClient,
-                                         int32_t priority, bool notifyFramesProcessed)
-    : BnEffect(),
+                                         int32_t priority, bool notifyFramesProcessed,
+                                         bool isInternal,
+                                         audio_utils::MutexOrder mutexOrder)
+    : BnEffect(), mMutex(mutexOrder),
     mEffect(effect), mEffectClient(media::EffectClientAsyncProxy::makeIfNeeded(effectClient)),
     mClient(client), mCblk(nullptr),
     mPriority(priority), mHasControl(false), mEnabled(false), mDisconnected(false),
-    mNotifyFramesProcessed(notifyFramesProcessed)
+    mNotifyFramesProcessed(notifyFramesProcessed), mIsInternal(isInternal)
 {
     ALOGV("constructor %p client %p", this, client.get());
     setMinSchedulerPolicy(SCHED_NORMAL, ANDROID_PRIORITY_AUDIO);
@@ -1939,7 +1944,7 @@
 
 void EffectHandle::disconnect(bool unpinIfLast)
 {
-    audio_utils::lock_guard _l(mutex());
+    audio_utils::unique_lock _l(mutex());
     ALOGV("disconnect(%s) %p", unpinIfLast ? "true" : "false", this);
     if (mDisconnected) {
         if (unpinIfLast) {
@@ -1951,11 +1956,19 @@
     {
         sp<IAfEffectBase> effect = mEffect.promote();
         if (effect != 0) {
+            // Unlock e.g. for device effect: may need to acquire AudioFlinger lock
+            // Also Internal Effect Handle would require Proxy lock (and vice versa).
+            if (isInternal()) {
+                _l.unlock();
+            }
             if (effect->disconnectHandle(this, unpinIfLast) > 0) {
                 ALOGW("%s Effect handle %p disconnected after thread destruction",
                     __func__, this);
             }
             effect->updatePolicyState();
+            if (isInternal()) {
+                _l.lock();
+            }
         }
     }
 
@@ -3544,8 +3557,7 @@
             }
             mHalEffect->configure_l();
         }
-        *handle = new EffectHandle(mHalEffect, nullptr, nullptr, 0 /*priority*/,
-                                   mNotifyFramesProcessed);
+        *handle = sp<InternalEffectHandle>::make(mHalEffect, mNotifyFramesProcessed);
         status = (*handle)->initCheck();
         if (status == OK) {
             status = mHalEffect->addHandle((*handle).get());
@@ -3592,15 +3604,16 @@
     return status;
 }
 
-void DeviceEffectProxy::onReleasePatch(audio_patch_handle_t patchHandle) {
-    sp<IAfEffectHandle> effect;
+sp<IAfEffectHandle> DeviceEffectProxy::onReleasePatch(audio_patch_handle_t patchHandle) {
+    sp<IAfEffectHandle> disconnectedHandle;
     {
         audio_utils::lock_guard _l(proxyMutex());
         if (mEffectHandles.find(patchHandle) != mEffectHandles.end()) {
-            effect = mEffectHandles.at(patchHandle);
+            disconnectedHandle = std::move(mEffectHandles.at(patchHandle));
             mEffectHandles.erase(patchHandle);
         }
     }
+    return disconnectedHandle;
 }
 
 
diff --git a/services/audioflinger/Effects.h b/services/audioflinger/Effects.h
index 830fe81..35e18d7 100644
--- a/services/audioflinger/Effects.h
+++ b/services/audioflinger/Effects.h
@@ -343,7 +343,8 @@
     EffectHandle(const sp<IAfEffectBase>& effect,
             const sp<Client>& client,
             const sp<media::IEffectClient>& effectClient,
-            int32_t priority, bool notifyFramesProcessed);
+            int32_t priority, bool notifyFramesProcessed, bool isInternal = false,
+            audio_utils::MutexOrder mutexOrder = audio_utils::MutexOrder::kEffectHandle_Mutex);
     ~EffectHandle() override;
     status_t onTransact(
             uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) final;
@@ -363,6 +364,11 @@
                                       int32_t* _aidl_return) final;
 
     const sp<Client>& client() const final { return mClient; }
+    /**
+     * Checks if the handle is internal, aka created by AudioFlinger for internal needs (e.g.
+     * device effect HAL handle or device effect thread handle).
+     */
+    virtual bool isInternal() const { return mIsInternal; }
 
     sp<android::media::IEffect> asIEffect() final {
         return sp<android::media::IEffect>::fromExisting(this);
@@ -400,15 +406,18 @@
 
     void dumpToBuffer(char* buffer, size_t size) const final;
 
+protected:
+    // protects IEffect method calls
+    mutable audio_utils::mutex mMutex;
 
 private:
     DISALLOW_COPY_AND_ASSIGN(EffectHandle);
 
-    audio_utils::mutex& mutex() const RETURN_CAPABILITY(android::audio_utils::EffectHandle_Mutex) {
+    virtual audio_utils::mutex& mutex() const
+            RETURN_CAPABILITY(android::audio_utils::EffectHandle_Mutex) {
         return mMutex;
     }
-    // protects IEffect method calls
-    mutable audio_utils::mutex mMutex{audio_utils::MutexOrder::kEffectHandle_Mutex};
+
     const wp<IAfEffectBase> mEffect;               // pointer to controlled EffectModule
     const sp<media::IEffectClient> mEffectClient;  // callback interface for client notifications
     /*const*/ sp<Client> mClient;            // client for shared memory allocation, see
@@ -424,6 +433,28 @@
     bool mDisconnected;                      // Set to true by disconnect()
     const bool mNotifyFramesProcessed;       // true if the client callback event
                                              // EVENT_FRAMES_PROCESSED must be generated
+    const bool mIsInternal;
+};
+
+/**
+ * There are 2 types of effects:
+ * -Session Effect: handle is directly called from the client, without AudioFlinger lock.
+ * -Device Effect: a device effect proxy is aggregating a collection of internal effect handles that
+ * controls the same effect added on all audio patches involving the device effect selected port
+ * requested either by a client or by AudioPolicyEffects. These internal effect handles do not have
+ * client. Sequence flow implies a different locking order, hence the lock is specialied.
+ */
+class InternalEffectHandle : public EffectHandle {
+public:
+    InternalEffectHandle(const sp<IAfEffectBase>& effect, bool notifyFramesProcessed) :
+            EffectHandle(effect, /* client= */ nullptr, /* effectClient= */ nullptr,
+                         /* priority= */ 0, notifyFramesProcessed, /* isInternal */ true,
+                         audio_utils::MutexOrder::kDeviceEffectHandle_Mutex) {}
+
+    virtual audio_utils::mutex& mutex() const
+            RETURN_CAPABILITY(android::audio_utils::DeviceEffectHandle_Mutex) {
+        return mMutex;
+    }
 };
 
 // the EffectChain class represents a group of effects associated to one audio session.
@@ -761,7 +792,7 @@
     status_t onUpdatePatch(audio_patch_handle_t oldPatchHandle, audio_patch_handle_t newPatchHandle,
            const IAfPatchPanel::Patch& patch) final;
 
-    void onReleasePatch(audio_patch_handle_t patchHandle) final;
+    sp<IAfEffectHandle> onReleasePatch(audio_patch_handle_t patchHandle) final;
 
     size_t removeEffect(const sp<IAfEffectModule>& effect) final;
 
diff --git a/services/audioflinger/IAfEffect.h b/services/audioflinger/IAfEffect.h
index f1edcfe..3452e94 100644
--- a/services/audioflinger/IAfEffect.h
+++ b/services/audioflinger/IAfEffect.h
@@ -400,7 +400,14 @@
     virtual status_t onUpdatePatch(audio_patch_handle_t oldPatchHandle,
             audio_patch_handle_t newPatchHandle,
             const IAfPatchPanel::Patch& patch) = 0;
-    virtual void onReleasePatch(audio_patch_handle_t patchHandle) = 0;
+    /**
+     * Checks (and release) of the effect handle is linked with the given release patch handle.
+     *
+     * @param patchHandle handle of the released patch
+     * @return a reference on the effect handle released if any, nullptr otherwise.
+     * It allows to delay the destruction of the handle.
+     */
+    virtual sp<IAfEffectHandle> onReleasePatch(audio_patch_handle_t patchHandle) = 0;
 
     virtual void dump2(int fd, int spaces) const = 0; // TODO(b/291319101) naming?