Can't reconnect to paired Bluetooth devices after toggling BT unless I re-pair

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1

I have a slightly strange issue where paired Bluetooth devices will fail to reconnect once the Bluetooth module is toggled (disable->enable) unless I unpair and re-pair them.

Reproduction steps:

  1. Pair headset with laptop, verify it works
  2. Disconnect and reconnect in the settings panel, verify it works
  3. Turn off Bluetooth, wait a couple of seconds, turn on Bluetooth
  4. Attempt connecting to the previous headset
  5. Observe connection failure

When the connection fails, the spinner in the Bluetooth panel spins for 20~30 seconds and then displays the following:

image

On running journalctl -xeu bluetooth I don’t see anything of note:

// ... truncated ...
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSource/faststream
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSource/faststream_duplex
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSink/opus_05
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSource/opus_05
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSink/opus_05_duplex
Mar 09 11:58:59 wendy bluetoothd[1350]: Endpoint unregistered: sender=:1.32 path=/MediaEndpoint/A2DPSource/opus_05_duplex
Mar 09 11:58:59 wendy bluetoothd[1350]: Battery Provider Manager destroyed
Mar 09 11:59:01 wendy bluetoothd[1350]: Battery Provider Manager created
Mar 09 11:59:01 wendy bluetoothd[1350]: src/device.c:device_set_wake_support() Unable to set wake_support without RPA resolution
Mar 09 11:59:01 wendy bluetoothd[1350]: Endpoint registered: sender=:1.32 path=/MediaEndpoint/A2DPSource/ldac
Mar 09 11:59:01 wendy bluetoothd[1350]: Endpoint registered: sender=:1.32 path=/MediaEndpoint/A2DPSink/aptx_hd
Mar 09 11:59:01 wendy bluetoothd[1350]: Endpoint registered: sender=:1.32 path=/MediaEndpoint/A2DPSource/aptx_hd
Mar 09 11:59:01 wendy bluetoothd[1350]: Endpoint registered: sender=:1.32 path=/MediaEndpoint/A2DPSink/aptx
Mar 09 11:59:01 wendy bluetoothd[1350]: Endpoint registered: sender=:1.32 path=/MediaEndpoint/A2DPSource/aptx
// ... truncated ...

This is what shows up in dmesg:

[11911.994054] Bluetooth: hci0: Waiting for firmware download to complete
[11911.994393] Bluetooth: hci0: Firmware loaded in 1753915 usecs
[11911.994577] Bluetooth: hci0: Waiting for device to boot
[11912.007576] Bluetooth: hci0: Device booted in 12856 usecs
[11912.007651] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-12-16.ddc
[11912.010587] Bluetooth: hci0: Applying Intel DDC parameters completed
[11912.011567] Bluetooth: hci0: Firmware revision 0.1 build 19 week 44 2021
[11912.013575] Bluetooth: hci0: Reading supported features failed (-16)
[11912.013596] Bluetooth: hci0: Error reading debug features
[11912.013623] Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.
[11912.066355] Bluetooth: MGMT ver 1.23

If I remove the device and re-pair it, it connects fine, audio plays, etc.
image

This is affecting the two headsets I’ve managed to test with (Buds2 Pro and WH-1000XM5). I’m using a ThinkPad T480 with the “Intel Corporation Wireless 8265 / 8275 (rev 78)” card according to lspci. I’m planning to install Windows and some other distro on a separate partition and verify whether this issue persists, but was wondering if anybody else ran into this issue in the meantime. Any replies would be appreciated!

2

So this appears to be a Linux issue, not a NixOS-specific issue.

I tested on Windows 11 and BT functioned as I expected it to. I then booted up a copy of Linux Mint and observed the same behavior.

Interestingly the kernel there gave me some more debug and error messages:

[  227.800732] Bluetooth: hci0: Bootloader revision 0.0 build 26 week 38 2015
[  227.801665] Bluetooth: hci0: Device revision is 16
[  227.801672] Bluetooth: hci0: Secure boot is enabled
[  227.801675] Bluetooth: hci0: OTP lock is enabled
[  227.801678] Bluetooth: hci0: API lock is enabled
[  227.801681] Bluetooth: hci0: Debug lock is disabled
[  227.801683] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
[  227.811738] Bluetooth: hci0: Found device firmware: intel/ibt-12-16.sfi
[  229.704576] Bluetooth: hci0: Waiting for firmware download to complete
[  229.704718] Bluetooth: hci0: Firmware loaded in 1848598 usecs
[  229.705015] Bluetooth: hci0: Waiting for device to boot
[  229.717720] Bluetooth: hci0: Device booted in 12586 usecs
[  229.717746] Bluetooth: hci0: Malformed MSFT vendor event: 0x02
[  229.720080] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-12-16.ddc
[  229.722814] Bluetooth: hci0: Applying Intel DDC parameters completed
[  229.723763] Bluetooth: hci0: Firmware revision 0.1 build 19 week 44 2021
[  229.725805] Bluetooth: hci0: Reading supported features failed (-16)
[  229.725821] Bluetooth: hci0: Error reading debug features
[  229.725831] Bluetooth: hci0: HCI LE Coded PHY feature bit is set, but its usage is not supported.
[  229.778571] Bluetooth: MGMT ver 1.22
[  229.834529] Bluetooth: hci0: Invalid link address type 1 for b0:54:76

The Linux Mint kernel was 6.8.0-51-generic, while I’m running 6.13.5 on NixOS. It appears that the Intel BT driver on Linux is faulty going back to 6.8.0 (and possibly before)…

3

Do you have fast boot enabled in windows? That can mess with hardware like wifi and bt cards.

4

I only installed Windows on a separate boot partition to confirm that it wasn’t a problem on Windows. This has been going on without Windows ever since I installed NixOS.

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