Android12显示两个MTP设备

./packages/services/Mtp/src/com/android/mtp/MtpService.java

    private final StorageEventListener mStorageEventListener = new StorageEventListener() {
        @Override
        public void onStorageStateChanged(String path, String oldState, String newState) {
            synchronized (MtpService.this) {
                Log.d(TAG, "onStorageStateChanged " + path + " " + oldState + " -> " + newState);
                if (Environment.MEDIA_MOUNTED.equals(newState)) {
                    // Updating mVolumes variable because new storage could be inserted
                    mVolumes = StorageManager.getVolumeList(getUserId(), 0);
                    for (int i = 0; i < mVolumes.length; i++) {
                        StorageVolume volume = mVolumes[i];
                        if (volume.getPath().equals(path)) {
                            boolean isAdd = false;
                            if (mVolumeMap.containsKey(path)) {
                                isAdd = true;
                            }

                            mVolumeMap.put(path, volume);
                            //bug1742334 PTP mode support new storage insert
                            if (mUnlocked && !isAdd/*&& (volume.isPrimary() || !mPtpMode)*/) {
                               addStorage(volume);
                            }  
                            break;
                        }
                    }
                } else if (Environment.MEDIA_MOUNTED.equals(oldState)) {
                    // bug1735580 Updating mVolumes variable because storage could be removed
                    mVolumes = StorageManager.getVolumeList(getUserId(), 0);
                    if (mVolumeMap.containsKey(path)) {
                        removeStorage(mVolumeMap.remove(path));
                    }
                }
            }
        }
    };

./frameworks/av/media/mtp/MtpServer.cpp

diff --git a/idh.code/frameworks/av/media/mtp/MtpServer.cpp b/idh.code/frameworks/av/media/mtp/MtpServer.cpp
index ebea14875c3..8fbe2d406d0 100755
--- a/idh.code/frameworks/av/media/mtp/MtpServer.cpp
+++ b/idh.code/frameworks/av/media/mtp/MtpServer.cpp
@@ -137,6 +137,10 @@ MtpServer::~MtpServer() {
 void MtpServer::addStorage(MtpStorage* storage) {
     std::lock_guard<std::mutex> lg(mMutex);

+    // avoid show two MTP devices.
+    if(hasStorage(storage->getStorageID()))
+       return;
+
     mStorages.push_back(storage);
     sendStoreAdded(storage->getStorageID());
 }