Bluetooth Audio is broken on Lenovo Legion Y700 Gen 4

[turbo-boo]

Current Behavior

Bluetooth audio device connects successfully and appears as "Active". However, media audio continues to play through the internal speakers.
When attempting to manually switch the output device via the Media Control panel (in Quick Settings/Notification shade), tapping the Bluetooth device causes a loading spinner to appear briefly, but the selection immediately reverts to "This phone". It is impossible to force the audio to the Bluetooth device.

Describe the bug

The system fails to route audio to the connected Bluetooth A2DP device. Manual intervention via the UI also fails; the system attempts to switch (indicated by the loading spinner) but aborts and defaults back to the internal speaker.

To Reproduce

1. Pair and connect a Bluetooth audio device.
2. Start media playback (e.g., VLC, YouTube). Audio plays from internal speakers.
3. Open the Media Control panel (from the notification shade).
4. Tap the specific Bluetooth device name to switch output.
5. Error: A loading spinner appears next to the Bluetooth device, but the checkmark remains on "This phone". Audio output never changes.

Expected behavior

The audio output should switch to the Bluetooth device immediately upon connection, or at least when manually selected in the Media Control panel.

Photos/Video

• Attached video: [screen-20250414-205817.mp4](https://github.com/user-attachments/assets/97ff3341-a2b4-4385-9b33-f27a268703e0)
• (The video demonstrates the inability to switch the output source in the UI)

Smartphone (please complete the following information):

• Device: Lenovo Legion Y700 Gen 4
• Firmware Version: TB322FC_CN_OPEN_USER_Q00041.1_V_ZUXOS_1.1.11.202_ST_250919
• Build Flavor: system-td-arm64-ab-vanilla.img.xz
• Version: android_15.0.0_r26 ci-20250415

Additional context

• Bluetooth Device used: QCY H3 Pro, BaseUS WM03
• I have tried forgetting and re-pairing the device, but the issue persists.
• Logs:
  boot.log
  play_audio_on_VLC.log
  pairing_to_a_earbuds.log

github-preview.mp4

[ildar]

You should try to apply fixes in Treble Settings (in Settings)

[turbo-boo]

You should try to apply fixes in Treble Settings (in Settings)

I tried that, but every setting gives me the broken results.
like, device will be can't even connect to the earbuds or device plays sound from speakers at max volume...

[Xavron]

Edit:

I see its happening in eg YouTube also so its unlikely to be VLC itself. It could in theory be Android's BT API, but idk. I'm probably not going to spend any further time to look at it at this point.

• Can also try this for a shot in the dark: https://www.reddit.com/r/GooglePixel/comments/r3o9er/if_you_are_having_bluetooth_issues_try_this/ if its there in Android here (I didn't look) "Enable developer options then search settings for "Disable Bluetooth A2DP hardware offload" this is in the off position by default, toggle it to enable it."

  • In the GSI ROM I use that is using the phh patches (not the one here) it is actually enabled and gets force enabled.

  • Also, in the GSI ROM I use that is using the phh patches (not the one here), Android force reboots (quick reboot, not sure if soft or other) when playing audio/video when keeping BT enabled but accessory device disabled then enabling the accessory device to switch over then pulling down the notification shade. So there's obviously problems there. Didn't appear to happen when BT is disabled then enabled but only when BT stays enabled but accessory is disabled. Didn't do full conflict testing so this could possibly change some. (Or this point could be from Android 16 QPR0 itself that I'm on.)

---

That Tablet it a 2025 model so it shouldn't be a hardware compat issue.

• I'm going to assume there isn't a compat issue between the hardware and accessories. That has potential to show up at rare times.

So, maybe its something like this in the logs:

AudioDevice{type: AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}, address: AudioDeviceAddress{mac: [164, 64, 61, 147, 49, 227]}}
04-14 20:51:04.356  5488  5489 D AHAL_ModuleBluetooth: populateConnectedDevicePort: isA2dpEnabled: 1
04-14 20:51:04.356  5488  5489 E AHAL_BluetoothAudioPort: initSessionType: device=AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}, session_type=A2DP_SOFTWARE_ENCODING_DATAPATH is not ready
04-14 20:51:04.356  5488  5489 E AHAL_ModuleBluetooth: createProxy: failed to register BT port for AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}
04-14 20:51:04.356  5488  5489 E AHAL_ModuleBluetooth: Function: populateConnectedDevicePort Line: 277 Failed 
04-14 20:51:04.356  5488  5489 W AHAL_BluetoothAudioPort: unregisterPort: BluetoothAudioPortAidl is not in use
04-14 20:51:04.356  5488  5489 E AHAL_Module: Function: connectExternalDevice Line: 637 Failed 
04-14 20:51:04.356  5499  5522 E Hal2AidlMapper: Function: setDevicePortConnectedState Line: 1060 Failed 
04-14 20:51:04.356  5499  5522 E APM_AudioPolicyManager: Error -38 while setting connected state 0 for device AUDIO_DEVICE_OUT_BLUETOOTH_A2DP, @:SUPPRESSED
04-14 20:51:04.356  5499  5522 W APM::Devices: DeviceVector::remove device 00000080 not in
04-14 20:51:04.356  5499  5522 E APM_AudioPolicyManager: setDeviceConnectionStateInt() device AUDIO_DEVICE_OUT_BLUETOOTH_A2DP, @: format 4000000 connection failed
04-14 20:51:04.356  2910  3614 E AudioSystem-JNI: Command failed for android_media_AudioSystem_setDeviceConnectionState: -38
04-14 20:51:04.356  2910  3614 E AS.AudioDeviceInventory: APM failed to make available A2DP device addr=XX:XX:XX:XX:31:E3 error=1
04-14 20:51:04.357  2910  3614 D BluetoothA2dp: getCodecStatus(XX:XX:XX:XX:31:E3)
04-14 20:51:04.358  2910  2910 V MediaRouter: Audio routes updated: AudioRoutesInfo{ type=SPEAKER, bluetoothName=Baseus Bowie WM03 }, a2dp=true

Might be related to something GrapheneOS had to deal with that showed some of these errors:

• https://github.com/GrapheneOS/os-issue-tracker/issues/221 and https://github.com/GrapheneOS/os-issue-tracker/issues/220 Link disabled so it doesn't show up in their project because Github is funny that way.

  • eg "AudioSystem-JNI: Command failed for android_media_AudioSystem_setDeviceConnectionState: -38"

[turbo-boo]

Edit:

I see its happening in eg YouTube also so its unlikely to be VLC itself. It could in theory be Android's BT API, but idk. I'm probably not going to spend any further time to look at it at this point.

• Can also try this for a shot in the dark: https://www.reddit.com/r/GooglePixel/comments/r3o9er/if_you_are_having_bluetooth_issues_try_this/ if its there in Android here (I didn't look) "Enable developer options then search settings for "Disable Bluetooth A2DP hardware offload" this is in the off position by default, toggle it to enable it."

  • In the GSI ROM I use that is using the phh patches (not the one here) it is actually enabled and gets force enabled.
  • Also, in the GSI ROM I use that is using the phh patches (not the one here), Android force reboots (quick reboot, not sure if soft or other) when playing audio/video when keeping BT enabled but accessory device disabled then enabling the accessory device to switch over then pulling down the notification shade. So there's obviously problems there. Didn't appear to happen when BT is disabled then enabled but only when BT stays enabled but accessory is disabled. Didn't do full conflict testing so this could possibly change some. (Or this point could be from Android 16 QPR0 itself that I'm on.)

That Tablet it a 2025 model so it shouldn't be a hardware compat issue.

• I'm going to assume there isn't a compat issue between the hardware and accessories. That has potential to show up at rare times.

So, maybe its something like this in the logs:

AudioDevice{type: AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}, address: AudioDeviceAddress{mac: [164, 64, 61, 147, 49, 227]}}
04-14 20:51:04.356  5488  5489 D AHAL_ModuleBluetooth: populateConnectedDevicePort: isA2dpEnabled: 1
04-14 20:51:04.356  5488  5489 E AHAL_BluetoothAudioPort: initSessionType: device=AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}, session_type=A2DP_SOFTWARE_ENCODING_DATAPATH is not ready
04-14 20:51:04.356  5488  5489 E AHAL_ModuleBluetooth: createProxy: failed to register BT port for AudioDeviceDescription{type: OUT_DEVICE, connection: bt-a2dp}
04-14 20:51:04.356  5488  5489 E AHAL_ModuleBluetooth: Function: populateConnectedDevicePort Line: 277 Failed 
04-14 20:51:04.356  5488  5489 W AHAL_BluetoothAudioPort: unregisterPort: BluetoothAudioPortAidl is not in use
04-14 20:51:04.356  5488  5489 E AHAL_Module: Function: connectExternalDevice Line: 637 Failed 
04-14 20:51:04.356  5499  5522 E Hal2AidlMapper: Function: setDevicePortConnectedState Line: 1060 Failed 
04-14 20:51:04.356  5499  5522 E APM_AudioPolicyManager: Error -38 while setting connected state 0 for device AUDIO_DEVICE_OUT_BLUETOOTH_A2DP, @:SUPPRESSED
04-14 20:51:04.356  5499  5522 W APM::Devices: DeviceVector::remove device 00000080 not in
04-14 20:51:04.356  5499  5522 E APM_AudioPolicyManager: setDeviceConnectionStateInt() device AUDIO_DEVICE_OUT_BLUETOOTH_A2DP, @: format 4000000 connection failed
04-14 20:51:04.356  2910  3614 E AudioSystem-JNI: Command failed for android_media_AudioSystem_setDeviceConnectionState: -38
04-14 20:51:04.356  2910  3614 E AS.AudioDeviceInventory: APM failed to make available A2DP device addr=XX:XX:XX:XX:31:E3 error=1
04-14 20:51:04.357  2910  3614 D BluetoothA2dp: getCodecStatus(XX:XX:XX:XX:31:E3)
04-14 20:51:04.358  2910  2910 V MediaRouter: Audio routes updated: AudioRoutesInfo{ type=SPEAKER, bluetoothName=Baseus Bowie WM03 }, a2dp=true

Might be related to something GrapheneOS had to deal with that showed some of these errors:

• https://github.com/GrapheneOS/os-issue-tracker/issues/221 and https://github.com/GrapheneOS/os-issue-tracker/issues/220 Link disabled so it doesn't show up in their project because Github is funny that way.

  • eg "AudioSystem-JNI: Command failed for android_media_AudioSystem_setDeviceConnectionState: -38"

I might have explained it poorly. Actually, sound comes from the speakers in all apps. It never comes through the Bluetooth headphones.

[Xavron]

No you didn't. That's the exact problem I noted in my post. Eg GrapheneOS problem that had been seen: "Setting the media output to phone or the BT device plays audio through the phone speakers."

I don't know if that could be a similar problem unfixed here, a newer difference problem, some other issue there, or elsewhere causing something similar. I didn't look at the code.

• It does show some of the exact same errors in your logs and stuff. And things GrapheneOS did to fix it there almost certainly won't kick back to this project here, and I get the impression its not a GrapheneOS only issue.

The issue that was in GrapheneOS was also affected by rebooting the device and some people found success by removing all BT devices and then adding back. Sometimes it took a few reboots. I don't know if your issue is affected in any of the same ways. There can also be some other variation or other workaround not thought of.

And the Android developer options do have various BT audio settings that can affect things like A2DP and affect the BT. In other words, possibly affect issues.

(The entire post focused on "sound comes from the speakers in all apps. It never comes through the Bluetooth headphones.".)

• It could possibly be a BT hardware compat issue (as this is GSI, otherwise this would be called as driver issue) with that specific device (but I suspect it may not be in this case).
  • Generally, this results in stuff like BT failing to enable, devices disconnecting, etc. On this device it gets enabled.
• If not, I would think its likely to be something like GrapheneOS had seen with the Android side code, a variation, or something newer.
• It doesn't appear to be app side BT code as you see it in all apps.
• It could be Google's Android BT API if they're all sharing the same API problem but I don't think its this.
• It doesn't appear to be the accessory device firmware BT code as its all connected devices.

Maybe that helps, idk. All I can do is try :)

• Looks like the Android source code may still contain same problems in theory (they don't seem to have made many changes in the past 5-6 years but it could be elsewhere or something unseen): https://android.googlesource.com/platform/frameworks/av/+/HEAD/services/audiopolicy/common/managerdefinitions/include/DeviceDescriptor.h#297

  • Compared to GrapheneOS change https://github.com/GrapheneOS-Archive/platform_frameworks_av/blob/e87af39cbe5a77f258625dc6f9f6253331667cac/services/audiopolicy/common/managerdefinitions/include/DeviceDescriptor.h#L211 Link disabled.

  • And I believe this is the Treble ROM https://github.com/TrebleDroid/platform_frameworks_av/blob/a9074f2fad90562844b1277bfae7b47b3925911c/services/audiopolicy/common/managerdefinitions/include/DeviceDescriptor.h#L297

However, it looks like the phh patches with System Wide BT HAL enabled runs their own code affecting A2DP and stuff. So, there can be a problem in the TrebleDroid code separate from anything else.

---

Variations found so far...

• (1) TrebleDroid > Misc > Disable System Wide BT HAL > Can now disable A2DP hardware offload in dev options > results in no sound on BT connected device nor phone speaker for me as long as BT device is connected (selecting this phone in VLC notification widget results in sound on phone speaker, but still no sound on BT device in any case). This is very close to the issue here. Indicates possible wrong settings combination.

  • I'm still not seeing the long forever loading circle so some other combination must exist.

• (2) Found a near or same match. The above point then enable System Wide BT HAL results in long forever loading circle when trying to switch audio devices in VLC and then failing. This is either the same or super close to the issue posted here. This is showing to me to be a settings combination issue.

  • Unsure what combination exactly would get it working here. I'm unsure if this is from user changes or from default enabled choices on this specific device of the issue above (not my device). Enabling System Wide BT HAL and rebooting works fine for me and it re-enabled disable A2DP hardware offload in dev options. So, idk from here.

  • With potential for bug or additional unforeseen issue on certain devices to be solved by phh patches that cannot be solved by current combinations. I have no idea if its this or if can be solved by current combinations. In my tests, simply enabling System Wide BT HAL and rebooting for good measure fixes it... but I didn't do full combination testing. And as I see it, it may only be a near match and not an exact one (unsure which).

  • One thing I do see is that there is potential for user breakage which could be considered a problem but also not necessarily be considered a problem to deal with. A dialog warning may not suffice either. I'd be more interested to know why some devices are backwards to need it, or is it based on Android version, or something else?

---

The above also shows there's possibilities of their A2DP or whatever code with System Wide BT HAL enabled having some issues where it can happen. They appear to be overriding Android's by what I'm seeing. So, there's potential where it could be issues with their code or at least there's something in there where it goes wrong temporarily anyway. They call their override sysbta.

I will leave it there.

[polygraphene]

I am facing the exact same issue. My device is the Y700 gen4. The inability to use Bluetooth audio is very problematic. I hope this issue can be resolved soon.

I have been trying to resolve this issue for several months since purchasing the device, but I have not yet achieved any clear success.

I would like to share what I have discovered so far:

1. The problem of Bluetooth audio not working occurs regardless of whether sysbta is enabled or disabled. (However, I feel that the behavior is slightly different between the on and off states.)
2. The issue also occurs with the official Google GSI ROMs. Since the official GSI naturally does not include patches derived from TrebleDroid, it uses the pure Android implementation (not sysbta).
3. The same problem occurs when building AOSP 15 or 16 (without TrebleDroid patches) as a GSI from my own source.
4. The logs don't clearly show anything failing? I compared the logs with a successful connection on the Stock ROM, but there are too many differences to understand clearly.
5. I'm not sure if it's related, but even on the Stock ROM (Lenovo ZUI/ZUXOS), if I disable "Bluetooth hardware offload" in the Developer options, the Bluetooth audio stops working properly.

I plan to do a more detailed analysis when I have time, for example, dynamic analysis using strace or gdb. I'm not very familiar with the implementation of the Bluetooth or audio stacks, so I would appreciate it if someone knowledgeable could take a look.

If only this issue could be resolved, it seems I could use TrebleDroid-based ROMs quite comfortably. I strongly hope for a solution.

[polygraphene]

I found a solution!
I could get it working by disabling sysbta and enabling hardware offload. It needs a patch on bluetooth stack.
I will send PR later.

[turbo-boo]

I found a solution! I could get it working by disabling sysbta and enabling hardware offload. It needs a patch on bluetooth stack. I will send PR later.

Great! I look forward to your PR.
I plan to open another issue soon, but do you happen to know a solution for this? I attempted to fix it myself but was unable to:

There is an issue on the Y700 (series) with GSI A16 where app-side rotation requests do not work. For example, even if a landscape-oriented game is launched while the screen is in portrait mode, the screen does not rotate and the game continues to run in portrait mode.

The screen rotation button that appears when rotating the device does work.

[polygraphene]

I can probably send a pull request in a couple of days.

I have same orientation issue. Is it related?
https://android-developers.googleblog.com/2025/01/orientation-and-resizability-changes-in-android-16.html

[turbo-boo]

I can probably send a pull request in a couple of days.

I have same orientation issue. Is it related? https://android-developers.googleblog.com/2025/01/orientation-and-resizability-changes-in-android-16.html

hmm, impressive
can you try "adb shell wm set-ignore-orientation-request false"? sadly I don't have a device right now

[polygraphene]

I created PR.
TrebleDroid/treble_app#49

hmm, impressive can you try "adb shell wm set-ignore-orientation-request false"? sadly I don't have a device right now

Thanks! The command fixed the issue.
According to the googleblog, this change only affected on apps with targetSdk=36 (Android16).
But it occurs also on older targetSdk.

[turbo-boo]

I created PR. TrebleDroid/treble_app#49

awesome work!