I found a config value in packages/app/Bluetooth/res/values/config.xml and a hide class
- android.bluetooth.BluetoothHeadsetClient, this provides HFP client API, such as dial, accept call.
I set profile_supported_hfpclient to true, and remake and flash the system. I write a test app to using BluetoothHeadsetClient API, and it can dial and accept call. However, the voice is not working when calling. The speaker doesn't make sound, and the voice received by mic isn't transferred by Bluetooth SCO.
So does android support HFP client fully? How can I make voice works well