[RTL8821CE] Bluetooth devices seem to pair well but the connection isn't working

[maxroby]

Bluetooth devices seem to pair well but the connection isn't working.

Trying to connect from console output:

Attempting to connect to ---
Failed to connect: org.bluez.Error.Failed

Ubuntu 21.10
bluez 5.60-0ubuntu2

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: bluez 5.60-0ubuntu2
ProcVersionSignature: Ubuntu 5.13.0-21.21-generic 5.13.18
Uname: Linux 5.13.0-21-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Mon Nov 15 14:22:35 2021
InstallationDate: Installed on 2020-09-15 (425 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: LENOVO 81LK
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.13.0-21-generic root=UUID=4caf9acd-f72f-4105-b822-542fc17f2c3a ro quiet splash vt.handoff=7
SourcePackage: bluez
UpgradeStatus: Upgraded to impish on 2021-09-28 (47 days ago)
dmi.bios.date: 11/24/2020
dmi.bios.release: 1.33
dmi.bios.vendor: LENOVO
dmi.bios.version: BGCN33WW
dmi.board.asset.tag: NO Asset Tag
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0R32862 WIN
dmi.chassis.asset.tag: NO Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: IdeaPad L340-15IRH Gaming
dmi.ec.firmware.release: 1.33
dmi.modalias: dmi:bvnLENOVO:bvrBGCN33WW:bd11/24/2020:br1.33:efr1.33:svnLENOVO:pn81LK:pvrIdeaPadL340-15IRHGaming:rvnLENOVO:rnLNVNB161216:rvrSDK0R32862WIN:cvnLENOVO:ct10:cvrIdeaPadL340-15IRHGaming:skuLENOVO_MT_81LK_BU_idea_FM_IdeaPadL340-15IRHGaming:
dmi.product.family: IdeaPad L340-15IRH Gaming
dmi.product.name: 81LK
dmi.product.sku: LENOVO_MT_81LK_BU_idea_FM_IdeaPad L340-15IRH Gaming
dmi.product.version: IdeaPad L340-15IRH Gaming
dmi.sys.vendor: LENOVO
hciconfig:
 hci0: Type: Primary Bus: USB
  BD Address: 28:39:26:88:F8:0C ACL MTU: 1021:8 SCO MTU: 255:12
  UP RUNNING PSCAN ISCAN
  RX bytes:17530 acl:8 sco:0 events:382 errors:0
  TX bytes:37498 acl:8 sco:0 commands:245 errors:0

[Jeremy (wa113y3s)]

This should be filed against package linux as the kernel provides bluetooth support, not the rtl8821ce package

[Daniel van Vugt (vanvugt)]

I'm not so sure.

The RTL8821CE chip implements Bluetooth according to the manufacturer (https://www.realtek.com/en/products/communications-network-ics/item/rtl8821ce) and the above attachment Lspci.txt says:

  Kernel driver in use: rtl8821ce

But then Lsusb.txt says it's running over the USB bus:

  Bus 001 Device 005: ID 0bda:c024 Realtek Semiconductor Corp. Bluetooth Radio

So I assume it's a USB device implemented on the PCIe card, whose driver is rtl8821ce. But we can add a kernel task in case I've missed anything...

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This change was made by a bot.

[maxroby (maxroby)]

I confirm that the last update of Bluetooth packages has resolved the issue.

[Daniel van Vugt (vanvugt)]

It might have been fixed by https://launchpad.net/ubuntu/+source/bluez/5.60-0ubuntu2.1 but it's still unclear... so let's just say fixed in 'Ubuntu'.

[maxroby (maxroby)]

Checking apt logs, it's since

bluez:amd64 (5.60-0ubuntu2, 5.60-0ubuntu2.1)

update that is working.

[Daniel van Vugt (vanvugt)]

OK. Usually security updates don't change behaviour visibly, but it's understandable if *sometimes* they do.