Bluetooth headset keeps randomly disconnecting

[oshunluvr]

A couple of these solutions may be helpful: https://askubuntu.com/questions/1331...-disconnecting

[pwlinwin]

A couple of these solutions may be helpful: https://askubuntu.com/questions/1331...-disconnecting

Thanks. I found this thread, but it didn't help.

I've found some other threads that match the same error in dmesg that I'm getting with the same chipset (AX200 series) and same behaviour, but they are all unresolved. It seems like its a driver issue.

[Schwarzer Kater]

[…] error in dmesg that I'm getting with the same chipset (AX200 series) and same behaviour […]

By chance I just read that you can order some of the TUXEDO notebooks with the AX200 chipset.
Perhaps it could be worth a try if your problem goes away with their kernel and drivers in their TUXEDO OS 2 - see Overview: Kubuntu, its parent and some of its siblings for more info and the link to the ISO.

[pwlinwin]

By chance I just read that you can order some of the TUXEDO notebooks with the AX200 chipset.
Perhaps it could be worth a try if your problem goes away with their kernel and drivers in their TUXEDO OS 2 - see Overview: Kubuntu, its parent and some of its siblings for more info and the link to the ISO.

Seems a shame to skip distros over such a small issue when literally everything else about my Kubuntu experience is working for me. I've dug into some more threads, and this issue does appear to cross distros. Even the arch users are reporting it. Something in the AX201 firmware.

I didn't notice this in my dmesg. I didn't realize that if I waited to long, the information gathered during boot would disappear from dmesg. (still getting the hang of linux). This is just after a boot.

Bluetooth: Core ver 2.22
NET: Registered PF_BLUETOOTH protocol family
Bluetooth: HCI device and connection manager initialized
Bluetooth: HCI socket layer initialized
Bluetooth: L2CAP socket layer initialized
Bluetooth: SCO socket layer initialized
Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.
Bluetooth: hci0: Opcode 0xfc1e failed: -16
Bluetooth: BNEP (Ethernet Emulation) ver 1.3
Bluetooth: BNEP filters: protocol multicast
Bluetooth: BNEP socket layer initialized
Bluetooth: MGMT ver 1.22
Bluetooth: RFCOMM TTY layer initialized
Bluetooth: RFCOMM socket layer initialized
Bluetooth: RFCOMM ver 1.11
Bluetooth: hci0: Invalid exception type 03
Bluetooth: hci0: Invalid exception type 03​

The following line caught my eye. It shows up on every thread I've found about this.

Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.
Bluetooth: hci0: Opcode 0xfc1e failed: -16

I'm trying to figure out how to turn LE (I assume Low energy mode) off, and get more information on the error under it..

Also the fact that I'm getting those type 03 exceptions at boot. Googling finds almost no results on those.

Its a learning experience if nothing else.

[Schwarzer Kater]

[…]
I'm trying to figure out how to turn LE (I assume Low energy mode) off, and get more information on the error under it.. […]

And did you try if powertop is of any use for that?

[pwlinwin]

I'm continuing to troubleshoot this as I get time. I may have found the most unexpected solution.

I ran across a thread the other day (I didn't bookmark it and can't find it again) that suggested that I update the AX201 driver in my windows installation (dual boot) with the official one supplied on the intel web page, as a possible resolution to this issue.

Apparently, the older driver packaged with windows update isn't the latest driver for the AX201 chipset. The poster seemed to think that while logged in to your windows partition, the older driver configures the adapter in such a way that manifests instability when rebooted into linux. This may explain why the problem only manifested some times and not others. I'm guessing that the times the bluetooth adapter was disconnected were following a reboot into linux from windows rather than a cold boot (power on) directly into linux.

This problem is reportedly corrected in the newer windows AX201 driver from intel.

I thought it was a long shot that updating the driver on my windows partition might fix the AX201 errors I'm getting on linux, but I've now gone several days without a disconnect and most of the errors have disappeared from dmesg.

[pwlinwin]

After a week, still no more dropouts. You can mark this as resolved.