[Galaxy Tab 2 (Unified 7" + 10.1") Android Developm] hamberthm:
Hi! I'll report a bug I hope somebody can fix. Bluetooth headsets in Call mode (with mic input) doesn't work. Any app using the BT headset in call mode will cause no audio output (it should be mono 8khz for call profile), nor mic input (also mono 8 khz i think).

Tested with many apps like Zoom, Google Duo, etc. This makes impossible to do videoconferencing or audio calls with connected BT Headphones, Earbuds, etc.

In these pandemic times, this is a dealbreaker for MANY people. I need the tablet to take online classes, so it would be awesome somebody can help.

Heres a Logcat when turning on BT Call Mode (headset profile) using the app "BTmono" to force it:

05-05 10:05:39.893 238 28015 I bt_a2dp_hw: start_audio_datapath: state 5
05-05 10:05:39.894 660 1003 W bt_btif : calculate_max_frames_per_packet Restricting AVDTP MTU size to 663
05-05 10:05:39.894 660 929 W bt_btif : bta_dm_rm_cback:3, status:7
05-05 10:05:39.919 540 1468 D BluetoothHeadset: startScoUsingVirtualVoiceCall()
05-05 10:05:39.921 660 929 I bt_hci_audio: set_audio_state handle:1 codec:0x1 state:3
05-05 10:05:39.922 660 929 D bt_hwcfg: hw_set_SCO_codec 0x1
05-05 10:05:39.948 660 909 I bt_hwcfg: SCO I2S interface change the sample rate to 8K
05-05 10:05:39.948 660 909 I bt_hwcfg: I2SPCM config {0x1, 0x1, 0x0, 0x1}
05-05 10:05:39.951 660 909 I bt_hwcfg: sco I2S/PCM config result 0 [0-Success, 1-Fail]
05-05 10:05:39.951 660 909 I bt_vendor: sco_audiostate_cb(status: 0)
05-05 10:05:40.646 660 994 D HeadsetStateMachine: Set NREC: 0 for device:00:02:3C:65:2E:F0
05-05 10:05:40.662 660 929 I bt_bta_av: bta_av_link_role_ok hndl:x41 role:0 conn_audio:x1 bits:1 features:x824b
05-05 10:05:40.662 660 929 W bt_btif : bta_dm_rm_cback:3, status:0
05-05 10:05:40.662 660 929 W bt_btif : bta_dm_rm_cback:3, status:7
05-05 10:05:40.662 238 28015 I bt_a2dp_hw: skt_connect: connect to /data/misc/bluedroid/.a2dp_data (sz 14336)
05-05 10:05:40.663 238 28015 I bt_a2dp_hw: skt_connect: connected to stack fd = 14
05-05 10:05:40.663 238 28015 W AudioFlinger: write blocked for 770 msecs, 4 delayed writes, thread 0xb2d83dc0
05-05 10:05:40.663 238 28015 I bt_a2dp_hw: out_set_parameters: state 1
05-05 10:05:40.663 238 28015 I hash_map_utils: key: 'a2dp_sink_address' value: '00:02:3C:65:2E:F0'
05-05 10:05:40.663 238 28015 I hash_map_utils: key: 'routing' value: '128'
05-05 10:05:40.663 238 28015 I bt_a2dp_hw: suspend_audio_datapath: state 1
05-05 10:05:40.664 660 1003 W bt_btif : pcm bytes per tick 3528
05-05 10:05:40.664 238 28015 I bt_a2dp_hw: skt_disconnect: fd 14
05-05 10:05:40.664 238 2354 I bt_a2dp_hw: adev_set_parameters: state 5
05-05 10:05:40.664 238 2354 I bt_a2dp_hw: out_set_parameters: state 5
05-05 10:05:40.664 238 2354 I hash_map_utils: key: 'bt_headset_nrec' value: 'off'
05-05 10:05:40.666 660 1003 W bt_btif : calculate_max_frames_per_packet Restricting AVDTP MTU size to 663
05-05 10:05:40.664 660 758 I BluetoothA2dpServiceJni: bta2dp_audio_state_callback
05-05 10:05:40.668 660 1002 D A2dpStateMachine: Connected process message: 101
05-05 10:05:40.670 238 639 I bt_a2dp_hw: adev_set_parameters: state 5
05-05 10:05:40.670 238 639 I bt_a2dp_hw: out_set_parameters: state 5
05-05 10:05:40.670 238 639 I hash_map_utils: key: 'bt_headset_name' value: 'Sound Blaster JAM'
05-05 10:05:40.672 660 1002 D A2dpStateMachine: A2DP Playing state : device: 00:02:3C:65:2E:F0 State:11->10
05-05 10:05:40.674 238 28776 E audio_hw_primary: Leaving IN_CALL state, in_call=0, mode=3
05-05 10:05:40.685 660 1003 W bt_btif : poll : channel detached remotely
05-05 10:05:40.685 660 1004 E bt_btif : warning : no command pending, ignore ack
05-05 10:05:40.685 660 1003 W bt_btif : ### UNDERFLOW :: ONLY READ 0 BYTES OUT OF 512 ###
05-05 10:05:40.685 660 1003 W bt_btif : btif_media_aa_prep_sbc_2_send underflow 5, 0
05-05 10:05:40.687 660 929 E bt_btif : bta_av_str_stopped:audio_open_cnt=1, p_data 9f47e988
05-05 10:05:40.687 660 929 W bt_btif : bta_dm_rm_cback:3, status:6
05-05 10:05:40.691 540 540 I Telecom : : mReceiver: HEADSET_AUDIO_STATE_CHANGED_ACTION: BM.oR@AE4
05-05 10:05:40.691 540 540 I Telecom : : ==> new state: 12: BM.oR@AE4
05-05 10:05:40.700 540 891 I Telecom : CallAudioRouteStateMachine: Message received: SWITCH_BLUETOOTH=1002, arg1=0: BM.oR->CARSM.pM_SWITCH_BLUETOOTH@AE4_0
05-05 10:05:40.704 660 1003 E bt_btif : UIPC_Read : channel 1 closed
05-05 10:05:40.704 660 1003 W bt_btif : ### UNDERFLOW :: ONLY READ 0 BYTES OUT OF 512 ###
05-05 10:05:40.704 660 1003 W bt_btif : btif_media_aa_prep_sbc_2_send underflow 5, 0
05-05 10:05:40.704 660 1003 E bt_btif : UIPC_Read : channel 1 closed
05-05 10:05:40.704 660 1003 W bt_btif : ### UNDERFLOW :: ONLY READ 0 BYTES OUT OF 512 ###
05-05 10:05:40.704 660 1003 W bt_btif : btif_media_aa_prep_sbc_2_send underflow 5, 0
05-05 10:05:40.724 660 1003 W bt_btif : btif_get_num_aa_frame_iteration() - Limiting frames to be sent from 20 to 14
05-05 10:05:40.724 660 1003 E bt_btif : UIPC_Read : channel 1 closed
05-05 10:05:40.724 660 1003 W bt_btif : ### UNDERFLOW :: ONLY READ 0 BYTES OUT OF 512 ###
05-05 10:05:40.724 660 1003 W bt_btif : btif_media_aa_prep_sbc_2_send underflow 5, 0
05-05 10:05:40.724 660 1003 E bt_btif : UIPC_Read : channel 1 closed
05-05 10:05:40.724 660 1003 W bt_btif : ### UNDERFLOW :: ONLY READ 0 BYTES OUT OF 512 ###
05-05 10:05:40.724 660 1003 W bt_btif : btif_media_aa_prep_sbc_2_send underflow 5, 0
05-05 10:05:40.735 540 4144 W AudioTrack: dead IAudioTrack, PCM, creating a new one from processAudioBuffer()
05-05 10:05:40.741 660 929 W bt_btif : bta_dm_rm_cback:3, status:6
05-05 10:05:40.742 660 758 I BluetoothA2dpServiceJni: bta2dp_audio_state_callback
05-05 10:05:40.743 660 1002 D A2dpStateMachine: Connected process message: 101
05-05 10:05:40.743 660 1003 E bt_btif : warning : no command pending, ignore ack
05-05 10:05:40.743 660 1003 W bt_btif : pcm bytes per tick 3528
05-05 10:05:40.746 660 1002 D A2dpStateMachine: A2DP Playing state : device: 00:02:3C:65:2E:F0 State:10->11
05-05 10:05:40.905 238 238 W AudioFlinger: createTrack_l(): mismatch between requested flags (00000004) and output flags (00000002)
05-05 10:05:40.914 540 4144 W AudioTrack: AUDIO_OUTPUT_FLAG_FAST denied by server; frameCount 4146
05-05 10:05:40.914 540 4144 D AudioTrack: restoring track at end of static buffer
05-05 10:05:41.246 540 1624 W art : Long monitor contention with owner Binder:540_11 (6132) at void com.android.server.audio.AudioService$VolumeStreamState.setAllIndexes(com.android.server.audio.AudioService$VolumeStreamState, java.lang.String)(AudioService.java:4106) waiters=0 in int com.android.server.audio.AudioService.getDevicesForStream(int, boolean) for 331ms
05-05 10:05:41.248 540 637 W art : Long monitor contention with owner Binder:540_11 (6132) at void com.android.server.audio.AudioService$VolumeStreamState.setAllIndexes(com.android.server.audio.AudioService$VolumeStreamState, java.lang.String)(AudioService.java:4106) waiters=1 in void com.android.server.audio.AudioService$AudioHandler.setDeviceVolume(com.android.server.audio.AudioService$VolumeStreamState, int) for 329ms
05-05 10:05:41.251 28191 28191 I Choreographer: Skipped 80 frames! The application may be doing too much work on its main thread.
05-05 10:05:41.254 681 781 I vol.Events: writeEvent level_changed STREAM_RING 5
05-05 10:05:41.260 681 781 I vol.Events: writeEvent level_changed STREAM_MUSIC 12
05-05 10:05:44.503 1244 1244 D BoundBrokerSvc: onUnbind: Intent { act=com.google.android.gms.ads.service.CACHE pkg=com.google.android.gms }
05-05 10:05:46.681 28191 28203 I PlayCore: UID: [10084] PID: [28191] PrewarmService : detach

I really hope somebody can help solve this! It´s present on all the 7 roms an even in 6 (tested also on RR 6).

Thanks!!